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JP5797418B2 - Bubble blowing device for reducing frictional resistance of ships - Google Patents

Bubble blowing device for reducing frictional resistance of ships Download PDF

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JP5797418B2
JP5797418B2 JP2011029651A JP2011029651A JP5797418B2 JP 5797418 B2 JP5797418 B2 JP 5797418B2 JP 2011029651 A JP2011029651 A JP 2011029651A JP 2011029651 A JP2011029651 A JP 2011029651A JP 5797418 B2 JP5797418 B2 JP 5797418B2
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ship
air
frictional resistance
outlet
blowing device
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JP2012166704A (en
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英幹 川島
英幹 川島
宗彦 日夏
宗彦 日夏
利文 堀
利文 堀
牧野 雅彦
雅彦 牧野
剛 石黒
剛 石黒
幸人 檜垣
幸人 檜垣
青 何
青 何
一之 箙
一之 箙
恭二 村上
恭二 村上
建剛 施
建剛 施
藤井 昭彦
昭彦 藤井
宗二 溝上
宗二 溝上
寿夫 田中
寿夫 田中
啓市 山崎
啓市 山崎
水野 克彦
克彦 水野
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B63SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63BSHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B1/00Hydrodynamic or hydrostatic features of hulls or of hydrofoils
    • B63B1/32Other means for varying the inherent hydrodynamic characteristics of hulls
    • B63B1/34Other means for varying the inherent hydrodynamic characteristics of hulls by reducing surface friction
    • B63B1/38Other means for varying the inherent hydrodynamic characteristics of hulls by reducing surface friction using air bubbles or air layers gas filled volumes
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B63SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63BSHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B1/00Hydrodynamic or hydrostatic features of hulls or of hydrofoils
    • B63B1/32Other means for varying the inherent hydrodynamic characteristics of hulls
    • B63B1/34Other means for varying the inherent hydrodynamic characteristics of hulls by reducing surface friction
    • B63B1/38Other means for varying the inherent hydrodynamic characteristics of hulls by reducing surface friction using air bubbles or air layers gas filled volumes
    • B63B2001/387Other means for varying the inherent hydrodynamic characteristics of hulls by reducing surface friction using air bubbles or air layers gas filled volumes using means for producing a film of air or air bubbles over at least a significant portion of the hull surface
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T70/00Maritime or waterways transport
    • Y02T70/10Measures concerning design or construction of watercraft hulls

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  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Aeration Devices For Treatment Of Activated Polluted Sludge (AREA)

Description

本発明は、航行中の船舶の船底部外面に沿う水の摩擦抵抗を低減させるための、船舶の摩擦抵抗低減用気泡吹出装置に関する。   The present invention relates to a bubble blowing device for reducing the frictional resistance of a ship for reducing the frictional resistance of water along the outer surface of the bottom of the ship being navigated.

航行中の船舶では、一般に船底部の没水表面に水の摩擦抵抗を受けており、特に大型船の場合には船体抵抗の大部分が船底部における外水の相対流により生じる摩擦抵抗で占められている。
そこで、航行時に船底面を気泡流で覆うことにより船体摩擦の低減を図る技術が提案されている(特許文献1〜5)。
特許文献1には、船底に空気噴出口を設けて船底と水との間に空気層を介在させることにより船体の摩擦抵抗を低減させる船が記載されている。そして、この船において、船が動揺するときに、船底の傾斜方向に応じて空気が高い方に向かって流れ、摩擦抵抗の減少程度が減殺される場合があり、この減殺率を小さくすることを目的として、船の傾斜に応じて、船底が浅くなる側の噴出口からの噴出量を減少させ、深くなる側の噴出量を増加させるように空気の流量を制御する構成が記載されている。
特許文献2には、船体摩擦抵抗低減装置において、船底部を覆う気泡の配分を無駄なく適切に行うことを目的として、横揺れセンサで検出される船体横傾斜角に基づいて船底部の幅方向にわたり分割された複数の分室に供給する高圧気体供給量を制御する構成が記載されている。
特許文献3には、船体摩擦抵抗低減装置において、船体強度の低下を抑制しつつ、船底に形成される気泡膜の形成領域を拡大することを目的として、中央空気噴出孔群の船幅方向における長さを側方空気噴出孔群の船幅方向における長さに比して長く形成する構成が記載されている。
特許文献4には、船体摩擦抵抗低減装置において船底に形成された複数の空気噴出孔から均一に空気を噴出することを目的として、エアーチャンバ内部に空気供給口と複数の空気噴出口の間に介在させた空気拡散板を設け、当該空気拡散板が空気供給口に対面する供給口対面領域と複数の空気噴出口の配列方向の両端部に対面する一対の噴出孔対面領域とを含むように形成する構成が記載されている。
特許文献5には、船体摩擦抵抗低減方法において、船側の気泡の滞留期間を延ばすことを目的として、船側部から吹き出させる加圧空気を、船速よりも早い吹出し速度として船体の斜め後方に向けて吹き出すと共に、船側部で発生させる微小気泡を船底部で発生させるものよりも小さい直径とする構成が記載されている。
In navigating vessels, the submerged surface of the bottom of the ship generally receives frictional resistance of water, and in the case of large ships in particular, most of the hull resistance is occupied by the frictional resistance generated by the relative flow of outside water at the bottom of the ship. It has been.
In view of this, techniques for reducing the hull friction by covering the bottom of the ship with a bubbly flow during navigation have been proposed (Patent Documents 1 to 5).
Patent Document 1 describes a ship that reduces the frictional resistance of the hull by providing an air jet on the ship bottom and interposing an air layer between the ship bottom and water. In this ship, when the ship shakes, the air flows toward the higher direction according to the inclination direction of the ship bottom, and the reduction degree of the frictional resistance may be reduced. As an object, there is described a configuration in which the flow rate of air is controlled so as to decrease the amount of ejection from the jet outlet on the side where the ship bottom becomes shallower and increase the amount of ejection on the deeper side according to the inclination of the ship.
In Patent Document 2, in the hull frictional resistance reduction device, the width direction of the bottom of the ship is determined based on the hull lateral inclination angle detected by the roll sensor for the purpose of appropriately distributing bubbles covering the bottom of the ship without waste. The structure which controls the high-pressure gas supply_amount | feed_rate supplied to the several compartment divided | segmented over is described.
In Patent Document 3, in the hull frictional resistance reduction device, in order to expand the formation region of the bubble film formed on the ship bottom while suppressing the decrease in hull strength, A configuration is described in which the length is longer than the length of the side air ejection hole group in the ship width direction.
In Patent Document 4, in the hull frictional resistance reduction device, for the purpose of uniformly ejecting air from a plurality of air ejection holes formed in the ship bottom, an air chamber is provided between an air supply port and a plurality of air ejection ports. An interposed air diffusion plate is provided, and the air diffusion plate includes a supply port facing region facing the air supply port and a pair of ejection hole facing regions facing both ends in the arrangement direction of the plurality of air ejection ports. The structure to be formed is described.
In Patent Document 5, in the hull frictional resistance reduction method, the pressurized air blown from the ship side is directed obliquely rearward of the hull as a blowing speed faster than the ship speed for the purpose of extending the residence time of bubbles on the ship side. In addition, a configuration is described in which the microbubbles generated at the side of the ship are smaller in diameter than those generated at the bottom of the ship.

特開昭60−163784号公報JP 60-163784 A 特開2008−13128号公報JP 2008-13128 A 特開2010−120607号公報JP 2010-120607 A 特開2010−120609号公報JP 2010-120609 A 特開平11−227674号公報JP-A-11-227474

航行時に船底面を気泡流で覆うことにより船体摩擦の低減を図る空気等を用いた潤滑法を大型船舶に適用する場合、船底をなるべく均一に気泡で被覆する必要がある。このため、複数個の空気吹き出し部を船幅方向に幅広く配置する必要がある。このような大型船舶は、例えばパナマックスバルクキャリアで全幅が約33m、VLCC(超大型タンカー)で全幅が約60mと幅が広い。仮に船底の幅が全幅の90%であると仮定すると、5度の横傾斜による船底における水面からの垂直方向の距離の差(以下、「水位差」という)の最大値は、バルクキャリアで2.6m、VLCCで4.7mとなる。このように、船底における水位差が大きくなると、各空気吹き出し部における圧力差が大きくなるため、各吹き出し部への空気供給系統は、独立させるか、配管に制御弁を設けて、各吹き出し部に供給する空気の量を均一化する必要がある。
一方、船底に配置した各吹き出し部も、各吹き出し部での相当空気膜厚さが厚くなりすぎると抵抗低減効果が低下するため、各吹き出し部の幅を広く取る必要がある。そのため各吹き出し部は、船幅方向に数メートルの幅を持つことになる。例えば吹き出し部の幅が3mあったとすると、5度の横傾斜でその両端での水位差は26cmにもなる。船の横傾斜時に抵抗低減の効果が低下しにくくするためには、各吹き出し部においても、なるべく均一に空気が吹き出される必要がある。
特許文献1には、上記の横傾斜時における抵抗低減の効果を低下させないために、空気の流量を制御する必要性が示唆されている。しかし、同文献には、空気の流量を制御するための構成について何ら記載されていない。
特許文献2には、船底部を覆う気泡の配分を無駄なく適切に行うことを目的として、複数の分室に供給する高圧気体供給量を制御する構成が記載されている。しかし、各吹き出し部を複数の区画に分けて、各吹き出し部への空気供給系統は、独立させるか、配管に制御弁を設けて、各吹き出し部に供給する空気の量を均一化する構成には、コスト面、信頼性の観点における問題がある。また、気吹き出し孔を非常に小さくして、圧損を稼ぎ均一化を図るという方法もあるが、空気の下向き吹き出し速度が過大になることや、空気供給側の圧力を増大させる必要があり、どちらも抵抗低減の効果を落とすことから、現実的では無い。
なお、特許文献3〜5に記載の構成は、船舶の横傾斜を原因とする抵抗低減の効果低下の問題を解決するものではない。
そこで、本発明は、ローリングにより船舶に横傾斜が生じる場合であっても、吹き出される空気量が不均一化することなく、船体摩擦の抵抗低減の効果が低下することを抑制することが可能な船舶の摩擦抵抗低減用気泡吹出装置を提供することを目的とする。
When applying a lubrication method using air or the like to reduce hull friction by covering the bottom of the ship with a bubbly flow during navigation, it is necessary to cover the bottom of the ship with bubbles as uniformly as possible. For this reason, it is necessary to arrange a plurality of air blowing portions widely in the ship width direction. Such a large vessel has a wide width of, for example, a Panamax bulk carrier with a total width of about 33 m and a VLCC (very large tanker) with a total width of about 60 m. Assuming that the width of the bottom of the ship is 90% of the total width, the maximum difference in the vertical distance from the water surface (hereinafter referred to as the “water level difference”) at the bottom of the ship due to the 5 ° lateral inclination is 2 for the bulk carrier. 0.6 m and 4.7 m by VLCC. In this way, when the water level difference at the bottom of the ship increases, the pressure difference at each air blowing section increases.Therefore, the air supply system to each blowing section is made independent or a control valve is provided in the piping, It is necessary to equalize the amount of air to be supplied.
On the other hand, each blowing section arranged on the bottom of the ship also needs to have a wide width for each blowing section because the resistance reduction effect decreases if the equivalent air film thickness at each blowing section becomes too thick. Therefore, each blowing portion has a width of several meters in the ship width direction. For example, if the width of the blowout part is 3 m, the water level difference at both ends is as much as 26 cm with a horizontal inclination of 5 degrees. In order to make it difficult for the resistance reduction effect to decrease when the ship is tilted sideways, it is necessary to blow out air as uniformly as possible in each blowing section.
Patent Document 1 suggests the necessity of controlling the flow rate of air in order not to reduce the effect of reducing resistance during the above-described lateral inclination. However, the document does not describe any configuration for controlling the air flow rate.
Patent Document 2 describes a configuration for controlling the amount of high-pressure gas supplied to a plurality of compartments for the purpose of appropriately distributing bubbles covering the ship bottom without waste. However, each blowing section is divided into a plurality of sections, and the air supply system to each blowing section is made independent, or a control valve is provided in the pipe so that the amount of air supplied to each blowing section is made uniform. However, there are problems in terms of cost and reliability. In addition, there is a method of making the air blowing hole very small to increase pressure loss and make it uniform, but it is necessary to increase the downward blowing speed of the air or increase the pressure on the air supply side. However, since the effect of reducing the resistance is reduced, it is not realistic.
In addition, the structure of patent documents 3-5 does not solve the problem of the effect reduction of the resistance reduction resulting from the horizontal inclination of a ship.
Therefore, the present invention can suppress a reduction in the effect of reducing the resistance of the hull friction without causing the amount of air to be blown out evenly, even when the ship is laterally inclined due to rolling. An object is to provide a bubble blowing device for reducing frictional resistance of a ship.

請求項1に記載の本発明の船舶の摩擦抵抗低減用気泡吹出装置は、船舶の周囲に気泡を噴出し摩擦抵抗を低減する摩擦抵抗低減用気泡吹出装置において、前記船舶の船底に複数設けた吹出口と、送気手段から送気される気体を受けて前記吹出口に供給するチャンバーとを備え、前記チャンバーと前記吹出口の間の隔壁に前記吹出口への気体供給孔を複数配置するとともに、複数の前記吹出口のうち、端部の前記吹出口への複数の前記気体供給孔の全てを前記船底の長手方向かつ前記船舶の前後中心線寄りに配置したことを特徴とする。
この構成により、複数の吹出口のうちの端部すなわち船舶の幅方向において最も外側に位置する吹出口に対して気体を供給する気体供給孔を、船底の長手方向かつ船舶の前後中心線寄りに配置することができる。
According to a first aspect of the present invention, there is provided a bubble blowing device for reducing frictional resistance of a ship according to the present invention, wherein a plurality of bubble blowing devices for reducing frictional resistance are provided on the bottom of the ship. A blower outlet, and a chamber that receives gas supplied from the air supply means and supplies the gas to the blower outlet, and a plurality of gas supply holes to the blower outlet are disposed in a partition wall between the chamber and the blower outlet. In addition, among the plurality of outlets , all of the plurality of gas supply holes to the outlet at the end are arranged in the longitudinal direction of the ship bottom and near the front and rear center lines of the ship .
With this configuration, the gas supply hole for supplying gas to the end of the plurality of outlets, that is, the outlet located on the outermost side in the width direction of the ship, is located in the longitudinal direction of the ship bottom and near the front and rear center lines of the ship. Can be arranged.

請求項2に記載の本発明の船舶の摩擦抵抗低減用気泡吹出装置は、船舶の周囲に気泡を噴出し摩擦抵抗を低減する摩擦抵抗低減用気泡吹出装置において、前記船舶の船底に設けた複数の吹出口を有した吹出口ブロックと、送気手段から送気される気体を受け前記吹出口ブロックに供給するチャンバーとを備え、前記チャンバーと前記吹出口の間の隔壁に前記吹出口への気体供給孔を複数配置するとともに、複数の前記吹出口のうち、端部の前記吹出口への複数の前記気体供給孔の全てを前記船底の長手方向かつ前記吹出口ブロックの前後中心線寄りに配置したことを特徴とする。
この構成により、複数の吹出口のうちの端部すなわち吹出口ブロックにおける船舶の幅方向において最も外側に位置する吹出口に対して気体を供給する気体供給孔を、船底の長手方向かつ吹出口ブロックの前後中心線寄りに配置することができる。
請求項3に記載の本発明は、請求項2に記載の船舶の摩擦抵抗低減用気泡吹出装置において、複数の前記吹出口ブロックを前記船底に設け、複数の前記吹出口ブロックに対して送気される前記気体を独立して調節する送気制御手段をさらに備えたことを特徴とする。
この構成により、送気される気体を吹出口ブロック毎に調節することができる。
According to a second aspect of the present invention, there is provided a bubble blowing device for reducing frictional resistance of a ship according to the present invention, wherein a plurality of bubble blowing devices for reducing frictional resistance are provided on the bottom of the ship. And a chamber for receiving the gas supplied from the air supply means and supplying the air to the air outlet block, a partition wall between the chamber and the air outlet is connected to the air outlet. A plurality of gas supply holes are arranged, and among the plurality of air outlets, all of the gas supply holes to the air outlets at the end are arranged in the longitudinal direction of the ship bottom and near the front and rear center lines of the air outlet block. It is arranged.
With this configuration, the gas supply hole for supplying gas to the outermost outlet in the width direction of the ship in the end portion of the plurality of outlets, that is, the outlet block, is arranged in the longitudinal direction of the ship bottom and the outlet block. It can be arranged near the front and rear center lines.
According to a third aspect of the present invention, in the bubble blowing device for reducing frictional resistance of a ship according to the second aspect, a plurality of the outlet blocks are provided on the bottom of the ship, and air is supplied to the plurality of the outlet blocks. The apparatus further comprises air supply control means for independently adjusting the gas to be generated.
With this configuration, the gas to be supplied can be adjusted for each outlet block.

請求項4に記載の本発明は、請求項1から請求項3のうちの1項に記載の船舶の摩擦抵抗低減用気泡吹出装置において、前記吹出口が、高さ方向に厚みを有し後方に向かうに従い前記厚みが漸減するリセス型であることを特徴とする。
この構成により、吹出口における厚みの部分(リセス部分)において、気体と水とを混合することができる。
請求項5に記載の本発明は、請求項4に記載の船舶の摩擦抵抗低減用気泡吹出装置において、前記吹出口から前記船底の後方に向かって噴出される前記気泡の速度が前記船舶の船速の2倍以下であることを特徴とする。
この構成により、摩擦抵抗低減用気泡吹出装置の抵抗低減効果を向上させることができる。
According to a fourth aspect of the present invention, in the bubble blowing device for reducing frictional resistance of a ship according to one of the first to third aspects, the outlet has a thickness in the height direction and a rear side. It is characterized by a recess type in which the thickness gradually decreases as it goes to.
With this configuration, gas and water can be mixed in the thickness portion (recess portion) of the outlet.
According to a fifth aspect of the present invention, in the bubble blowing device for reducing a frictional resistance of a ship according to the fourth aspect, the speed of the bubbles blown out from the outlet toward the rear of the bottom of the ship is the ship of the ship. It is characterized by being no more than twice the speed.
With this configuration, the resistance reduction effect of the bubble blowing device for reducing frictional resistance can be improved.

請求項6に記載の本発明は、請求項1から請求項3のうちの1項に記載の船舶の摩擦抵抗低減用気泡吹出装置において、前記吹出口が板状構造を有し、気体噴出孔が下方に向かって空いた孔空型であることを特徴とする。
この構成により、吹出口を簡単な構成で実現することができる。
請求項7に記載の本発明は、請求項1から請求項3のうちの1項に記載の船舶の摩擦抵抗低減用気泡吹出装置において、前記吹出口あるいは前記吹出口ブロックが二重チャンバー構造であることを特徴とする。
請求項8に記載の本発明は、請求項7に記載の船舶の摩擦抵抗低減用気泡吹出装置において、前記吹出口から前記船底の下方に向かって噴出される前記気泡の速度を、前記船舶の船速と同等以下としたことを特徴とする。
この構成により、摩擦抵抗低減用気泡吹出装置の抵抗低減効果を向上させることができる。
According to a sixth aspect of the present invention, in the bubble blowing device for reducing frictional resistance of a ship according to one of the first to third aspects, the outlet has a plate-like structure, and the gas outlet Is a perforated mold that opens downward.
With this configuration, the air outlet can be realized with a simple configuration.
According to a seventh aspect of the present invention, in the bubble blowing device for reducing marine frictional resistance according to one of the first to third aspects, the air outlet or the air outlet block has a double chamber structure. It is characterized by being.
The present invention according to claim 8 is the bubble blowing device for reducing the frictional resistance of a ship according to claim 7, wherein the speed of the bubbles blown out from the outlet toward the bottom of the bottom of the ship is determined. It is characterized by being less than or equal to the ship speed.
With this configuration, the resistance reduction effect of the bubble blowing device for reducing frictional resistance can be improved.

請求項9に記載の本発明は、請求項5あるいは請求項8に記載の船舶の摩擦抵抗低減用気泡吹出装置において、噴出される前記気泡の前記速度を前記船速に応じて変えたことを特徴とする。
この構成により、船速が変化した場合であっても抵抗低減効果を良好に維持することができる。
請求項10に記載の本発明は、請求項1から請求項9のうちの1項に記載の船舶の摩擦抵抗低減用気泡吹出装置において、前記吹出口あるいは前記吹出口ブロックを船首部における前記船底の形状に沿って配置したことを特徴とする。
この構成により、船舶の進行により船底に沿って気体を含んだ層を形成することができる。
According to a ninth aspect of the present invention, in the bubble blowing device for reducing the frictional resistance of a ship according to the fifth or eighth aspect, the speed of the bubbles to be blown is changed according to the ship speed. Features.
With this configuration, the resistance reduction effect can be satisfactorily maintained even when the boat speed changes.
A tenth aspect of the present invention is the bubble blowing device for reducing the frictional resistance of a ship according to one of the first to ninth aspects, wherein the blowout port or the blowout block is the bottom of the ship at the bow. It arrange | positions along the shape of this.
With this configuration, a layer containing gas can be formed along the bottom of the ship as the ship advances.

本発明の船舶の摩擦抵抗低減用気泡吹出装置によれば、端部の吹出口に対して気体を供給する気体供給孔を船底の長手方向かつ船舶の前後中心線寄りに配置することができる。これにより、両端の吹出口への気体供給孔の距離が小さくなるから、船舶のローリングによる横傾斜が生じた場合に生じる吹出口における水位差を小さくすることができる。したがって、空気吹き出し部における圧力差を抑制して、抵抗低減の効果の低下を抑制することが可能となる。また、吹出口に気体を供給するチャンバーにより、送気手段から送気された気体を一旦受け、複数配置された気体供給孔から均一に、特に横傾斜が生じた場合でも端部の吹出口に対して均一に噴射させることができる。 According to the bubble blowing device for reducing the frictional resistance of a ship according to the present invention, the gas supply hole for supplying gas to the outlet at the end can be arranged in the longitudinal direction of the ship bottom and near the front and rear center line of the ship. Thereby, since the distance of the gas supply hole to the blower outlets at both ends is reduced, it is possible to reduce the water level difference at the blower outlet that occurs when a horizontal inclination occurs due to rolling of the ship. Therefore, it is possible to suppress a pressure difference in the air blowing portion and suppress a decrease in the effect of reducing the resistance. Moreover, the gas supplied from the air supply means is once received by the chamber for supplying the gas to the air outlet, and is uniformly supplied to the air outlet at the end portion even when a lateral inclination occurs uniformly from the plurality of gas supply holes. On the other hand, it can spray uniformly.

本発明の船舶の摩擦抵抗低減用気泡吹出装置によれば、各吹出口ブロックにおける端部の吹出口への気体供給孔を船底の長手方向かつ各吹出口ブロックの前後中心線寄りに配置することができる。これにより、各吹出口ブロックにおける両端の吹出口の距離が小さくなるから、船舶のローリングによる横傾斜が生じた場合に生じる各吹出口ブロックにおける吹出口の水位差を小さくすることができる。したがって、空気吹き出し部における圧力差を抑制して、抵抗低減の効果の低下を抑制することが可能となる。また、吹出口に気体を供給するチャンバーにより、送気手段から送気された気体を一旦受け、複数配置された気体供給孔から均一に、特に横傾斜が生じた場合でも端部の気体供給孔から均一に噴射させることができる。
また、複数の吹出口ブロックを船底に設け、複数の吹出口ブロックに対して送気される気体を独立して調節する送気制御手段をさらに備えた構成とすれば、送気制御手段によって送気される気体を複数の吹出口ブロック毎に制御することが可能となる。
According to the bubble blowing device for reducing frictional resistance of a ship according to the present invention, the gas supply holes to the blowout ports at the ends of the blowout block are arranged in the longitudinal direction of the ship bottom and near the front and rear center lines of the blowout blocks. Can do. Thereby, since the distance of the blower outlet of both ends in each blower outlet block becomes small, the water level difference of the blower outlet in each blower outlet block produced when the horizontal inclination by rolling of a ship arises can be made small. Therefore, it is possible to suppress a pressure difference in the air blowing portion and suppress a decrease in the effect of reducing the resistance. In addition, the gas supply hole at the end portion receives the gas supplied from the air supply means once by the chamber for supplying the gas to the air outlet, and even when a lateral inclination occurs evenly from the plurality of gas supply holes arranged. Can be sprayed uniformly.
In addition, if the air supply control means is provided with a plurality of air outlet blocks on the bottom of the ship and further adjusts the gas supplied to the air outlet blocks independently, the air supply control means supplies the air. The gas to be gas can be controlled for each of the plurality of outlet blocks.

本発明の船舶の摩擦抵抗低減用気泡吹出装置は、吹出口をリセス型とした構成とすれば、リセス部分において空気と水とを混合することができるから、船底に供給される気体の均一性を向上させることが可能となる。
また、吹出口をリセス型とした場合、吹出口から吹き出される気泡の速度を船舶の船速の2倍以下とすることにより、摩擦抵抗低減用気泡吹出装置の抵抗低減効果を向上させることができる。
The bubble blowing device for reducing the frictional resistance of a ship according to the present invention can mix air and water in the recessed portion if the outlet is configured as a recess, so that the uniformity of the gas supplied to the ship bottom is uniform. Can be improved.
In addition, when the outlet is a recess type, the resistance reduction effect of the frictional resistance reduction bubble blowing device can be improved by setting the speed of the bubbles blown out from the outlet to be twice or less the ship speed of the ship. it can.

本発明の船舶の摩擦抵抗低減用気泡吹出装置は、吹出口を孔空型とすれば、簡単な構成により吹出口を実現することが可能となる。
また、吹出口あるいは吹出口ブロックを二重チャンバー構造とすれば、吹出口側のチャンバーにおいて空気と水とを混合することができるから、船底に供給される気体の均一性を向上させることができる。
また、二重チャンバー構造とした場合、吹出口から船底の下方に向かって噴出される気泡の速度を、船舶の船速と同等以下とすることにより、摩擦抵抗低減用気泡吹出装置の抵抗低減効果を向上させることが可能となる。
The bubble blowing device for reducing frictional resistance of a ship according to the present invention can realize a blowout port with a simple configuration if the blowout port is a perforated type.
Further, if the air outlet or the air outlet block has a double chamber structure, air and water can be mixed in the air outlet side chamber, so that the uniformity of the gas supplied to the ship bottom can be improved. .
In addition, in the case of a double chamber structure, the resistance reduction effect of the bubble blowing device for reducing frictional resistance is achieved by setting the speed of the bubbles ejected from the outlet toward the bottom of the ship bottom to be equal to or lower than the ship speed of the ship. Can be improved.

本発明の船舶の摩擦抵抗低減用気泡吹出装置は、噴出される気泡の速度を船速に応じて変えた構成とすれば、船速が変化した場合であっても抵抗低減効果を良好に維持することができる。
また、本発明の船舶の摩擦抵抗低減用気泡吹出装置は、吹出口あるいは吹出口ブロックを船首部における船底の形状に沿って配置した構成とすれば、船舶の進行により船底に沿って気体を含んだ層を形成することができる。
If the bubble blowing device for reducing the frictional resistance of a ship according to the present invention has a configuration in which the speed of the bubble to be blown is changed according to the ship speed, the resistance reduction effect is maintained well even when the ship speed changes. can do.
Further, the bubble blowing device for reducing the frictional resistance of a ship according to the present invention includes a blowout port or a blowout block arranged along the shape of the bottom of the ship at the bow, so that gas is contained along the bottom of the ship as the ship advances. A layer can be formed.

第1の実施形態としての船舶の摩擦抵抗低減用気泡吹出装置の模式図であり、(a)船底側から見た平面図、(b)船首側から見た断面図(船底が水平な状態)、(c)船首側から見た断面図(船底が横方向に傾いた状態)BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of the bubble blowing apparatus for frictional resistance reduction of the ship as 1st Embodiment, (a) The top view seen from the ship bottom side, (b) The sectional view seen from the bow side (state where the ship bottom is horizontal) , (C) Cross section viewed from the bow side (the state where the bottom of the ship is tilted laterally) 図1の船舶の摩擦抵抗低減用気泡吹出装置の模式図であり、船側から見た断面図(船底が水平な状態)It is a schematic diagram of the bubble blowing apparatus for reducing the frictional resistance of the ship of FIG. 1, and is a sectional view seen from the ship side (a state where the ship bottom is horizontal) 図1の船舶の摩擦抵抗低減用気泡吹出装置が配置された船底を船底側から見た状態を示す模式図The schematic diagram which shows the state which looked at the ship bottom by which the bubble blowing apparatus for frictional resistance reduction of the ship of FIG. 1 was arrange | positioned from the ship bottom side 船舶の摩擦抵抗低減用気泡吹出装置が船首部における船底の形状に沿って配置された構成を甲板側から見た断面模式図A cross-sectional schematic view of a configuration in which a bubble blowing device for reducing the frictional resistance of a ship is arranged along the shape of the bottom of the ship at the bow, viewed from the deck side 第1の実施形態としての船舶の摩擦抵抗低減用気泡吹出装置の実験に用いたモデルの構造を示す模式図であり、(a)リセス型の吹出口に相当する構成を側面から見た断面図、(b)開口型の吹出口に相当する構成を側面から見た断面図It is a schematic diagram which shows the structure of the model used for the experiment of the bubble blowing apparatus for reducing the frictional resistance of the ship as 1st Embodiment, (a) Sectional drawing which looked at the structure corresponded to a recess type blower outlet from the side surface (B) Sectional drawing which looked at the structure corresponded to an opening type blower outlet from the side surface 図5に示したモデルを用いて、供給する空気の量を変化させることにより、吹出速度を変化させた場合の抵抗低減効果を示すグラフThe graph which shows the resistance reduction effect at the time of changing the blowing speed by changing the quantity of the air to supply using the model shown in FIG. 第2の実施形態としての船舶の摩擦抵抗低減用気泡吹出装置の模式図であり、(a)船底側から見た平面図、(b)船首側から見た断面図It is a schematic diagram of a bubble blowing device for reducing frictional resistance of a ship as a second embodiment, (a) a plan view seen from the bottom of the ship, (b) a cross-sectional view seen from the bow side 第2の実施形態としての船舶の摩擦抵抗低減用気泡吹出装置の実験に用いたモデルの構造を模式的に示す断面図Sectional drawing which shows typically the structure of the model used for the experiment of the bubble blowing apparatus for frictional resistance reduction of the ship as 2nd Embodiment 第2の実施形態としての船舶の摩擦抵抗低減用気泡吹出装置の実験に用いた開口板の構造を示す平面図The top view which shows the structure of the aperture plate used for the experiment of the bubble blowing apparatus for ship frictional resistance reduction as 2nd Embodiment 図8、図9に示したモデルを用いて、供給する空気の量を変化させることにより、開口からの吹出速度を変化させた場合の抵抗低減効果を示すグラフ8 and 9 are graphs showing the resistance reduction effect when the blowing speed from the opening is changed by changing the amount of air to be supplied using the models shown in FIGS. 第3の実施形態としての船舶の摩擦抵抗低減用気泡吹出装置の模式図であり、(a)船底側から見た平面図、(b)船首側から見た断面図(船底が水平な状態)、(c)船首側から見た断面図(船底が横方向に傾いた状態)It is a schematic diagram of a bubble blowing device for reducing frictional resistance of a ship as a third embodiment, (a) a plan view seen from the ship bottom side, (b) a sectional view seen from the bow side (a state where the ship bottom is horizontal) , (C) Cross section viewed from the bow side (the state where the bottom of the ship is tilted laterally) 第4の実施形態としての船舶の摩擦抵抗低減用気泡吹出装置を構成する吹出口ブロックの概略を示す模式図The schematic diagram which shows the outline of the blower outlet block which comprises the bubble blowing apparatus for frictional resistance reduction of the ship as 4th Embodiment 第4の実施形態としての摩擦抵抗低減用気泡吹出装置を船底側から見た模式図The schematic diagram which looked at the bubble blowing apparatus for frictional resistance reduction as 4th Embodiment from the ship bottom side 開発に当たり当初検討した船舶の摩擦抵抗低減用気泡吹出装置の模式図であり、(a)船底側から見た平面図、(b)船首側から見た断面図(船底が水平な状態)、(c)船首側から見た断面図(船底が横方向に傾いた状態)It is a schematic diagram of a bubble blowing device for reducing frictional resistance of a ship that was initially examined in development, (a) a plan view seen from the bottom of the ship, (b) a cross-sectional view seen from the bow (with the ship bottom horizontal), c) Cross section viewed from the bow side (the bottom of the ship is tilted laterally)

本発明の船舶の摩擦抵抗低減用気泡吹出装置により船底に形成される相当空気膜厚tは、模型船実験においては下記の式により求められる。
=Q/(B・U
(t:空気相当膜厚、Qa:空気流量、B:空気被覆幅(船体全幅)、U:模型船速度)
空気相当膜厚(t)が8mm前後となるまでは、空気相当膜厚の増加にほぼ比例して、船舶の抵抗低減率が増加する。しかし、空気相当膜厚が8mmを超えると抵抗低減効果が飽和し始める。そして、空気相当膜厚が12mm〜14mm程度を超えると、気泡流は気膜状になり、空気量を増加しても抵抗低減効果がほとんど向上しなくなる。そこで、空気潤滑法による抵抗低減効果を高めるためには、空気吹き出し部での空気膜厚が、大きくなりすぎないようにする必要がある。そのためには、船底に配置した各吹き出し部を船幅方向に広く取る必要がある。したがって、各吹き出し部は、実船においては船幅方向に数メートルの幅を持つことになる。
Equivalent air film thickness t b is formed on the ship's bottom by drag reduction for bubble blowing device of the ship of the present invention is determined by the following equation in model ship experiments.
t b = Q a / (B a · U m )
(T b: air equivalent thickness, Q a: air flow rate, B a: the air coating width (Hull full width), U m: model ship speed)
Until the air equivalent film thickness (t b ) reaches about 8 mm, the resistance reduction rate of the ship increases almost in proportion to the increase in the air equivalent film thickness. However, when the air equivalent film thickness exceeds 8 mm, the resistance reduction effect starts to saturate. When the air equivalent film thickness exceeds about 12 mm to 14 mm, the bubble flow becomes a film shape, and the resistance reduction effect is hardly improved even if the air amount is increased. Therefore, in order to enhance the resistance reduction effect by the air lubrication method, it is necessary to prevent the air film thickness at the air blowing portion from becoming too large. For that purpose, it is necessary to widen each blowing part arranged on the ship bottom in the ship width direction. Therefore, each blowing section has a width of several meters in the ship width direction on an actual ship.

図14は、開発に当たり当初検討した船舶の摩擦抵抗低減用気泡吹出装置の模式図であり、(a)は船底側から見た平面図を、(b)は船首側から見た断面図(船底が水平な状態)を、(c)は船首側から見た断面図(船底が横方向に傾いた状態)をそれぞれ示している。同図(a)に示すように、船底101において空気供給孔102を幅方向に広くとった場合、(b)に示すように、船に横方向の傾斜が無い場合は船底101が水平となるから、船幅方向における両端の空気供給孔102の間の水平距離Hが大きくても、空気供給孔102から船外の海水20に対して空気を均一に吹き出すことができる。
しかし、(c)に示すように、船舶が横方向に傾斜した場合、空気供給孔102の水面からの垂直方向の距離(以下、「水位」という。)に水位差Lが生じる。この水位差Lが大きくなると各空気供給孔102にかかる水圧差が大きくなり、空気供給孔102からの空気噴出量が不均一となることにより、船舶の摩擦抵抗低減効果が低下するという問題が生じる。なお、水平距離Hと水位差Lとの間には、船の横方向の傾斜が同じであれば、水平距離Hが大きくなるに従って水位差Lも大きくなるという関係がある。
FIG. 14 is a schematic view of a bubble blowing device for reducing frictional resistance of a ship, which was initially examined in development, wherein (a) is a plan view viewed from the bottom side, and (b) is a cross-sectional view viewed from the bow side (the bottom of the ship). (C) shows a cross-sectional view (a state where the bottom of the ship is inclined in the lateral direction) viewed from the bow side. As shown in FIG. 6A, when the air supply hole 102 is wide in the width direction in the bottom 101, the bottom 101 becomes horizontal when the ship has no lateral inclination as shown in FIG. Therefore, even if the horizontal distance H between the air supply holes 102 at both ends in the ship width direction is large, the air can be uniformly blown from the air supply hole 102 to the seawater 20 outside the ship.
However, as shown in (c), when the ship is inclined in the lateral direction, a water level difference L is generated in a vertical distance from the water surface of the air supply hole 102 (hereinafter referred to as “water level”). When the water level difference L increases, the water pressure difference applied to each air supply hole 102 increases, and the amount of air jetted from the air supply hole 102 becomes non-uniform, resulting in a problem that the effect of reducing the frictional resistance of the ship is reduced. . Note that there is a relationship between the horizontal distance H and the water level difference L that the water level difference L increases as the horizontal distance H increases if the horizontal inclination of the ship is the same.

(第1の実施形態)
本実施形態の船舶の摩擦抵抗低減用気泡吹出装置は、吹出口を高さ方向に厚みを有し後方に向かうに従い厚みが漸減するリセス型としたものである。
図1は、本実施形態の船舶の摩擦抵抗低減用気泡吹出装置30の模式図であり、(a)は船底側から見た平面図を、(b)は船首側から見た断面図(船底が水平な状態)、(c)は船首側から見た断面図(船底が横方向に傾いた状態)をそれぞれ示している。同図に示すように、本実施形態の船舶の摩擦抵抗低減用気泡吹出装置30は、船舶の船底11に複数設けた吹出口32と、送気手段13(図示しないブロワーを含む)から送気される空気を受けて吹出口32に供給する第1チャンバー34を複数備えており、第1チャンバー34と吹出口32との間の隔壁36に、吹出口32への気体供給孔35を複数配置するとともに、複数の吹出口32のうちの船幅方向における端部の吹出口32への気体供給孔35を船底の長手方向(船舶の前後方向、図(a)では図面の上下方向)に配置している。なお、チャンバーとは特定目的のために仕切られた空間のことをいい、本実施形態においては、送気手段から送気される空気を受けて吹出口に供給する目的のために設けられた空間を第1チャンバーという。
この構成により、図14に示す開発にあたり当初検討した船舶の摩擦抵抗低減用気泡吹出装置と吹出口の数を同じとしながら、船幅方向の両端の吹出口32に気体を供給する気体供給孔35の間の水平距離H1を小さくすることができる。これにより、(c)に示す横方向に傾いた状態において、船幅方向における両端の気体供給孔35の水位差L1を小さくすることができる。また、吹出口32の船幅方向における水平方向幅H2を広くとりながら、船幅方向両端の吹出口32に気体を供給する気体供給孔35の間の水平方向距離H1を小さくすることができる。これにより、横方向に傾いた状態における気体供給孔35の水位差L1を吹出口32の水位差L2よりも小さくすることができる。したがって、水位差L1に起因して気体供給孔35からの空気噴出量が不均一となることによって船舶の摩擦抵抗低減効果が低下するという問題を抑制することが可能となる。
(First embodiment)
The bubble blowing device for reducing frictional resistance of a ship according to this embodiment is a recess type in which the outlet has a thickness in the height direction and gradually decreases in thickness toward the rear.
1A and 1B are schematic views of a bubble blowing device 30 for reducing frictional resistance of a ship according to the present embodiment. FIG. 1A is a plan view viewed from the bottom of the ship, and FIG. 1B is a cross-sectional view viewed from the bow side. (C) shows a cross-sectional view (a state where the bottom of the ship is tilted laterally) viewed from the bow side. As shown in the figure, the bubble blowing device 30 for reducing the frictional resistance of a ship according to this embodiment supplies air from a plurality of air outlets 32 provided on the ship bottom 11 and air supply means 13 (including a blower not shown). A plurality of first chambers 34 that receive the air to be supplied to the blower outlet 32 are provided, and a plurality of gas supply holes 35 to the blower outlet 32 are arranged in the partition wall 36 between the first chamber 34 and the blower outlet 32. as well as, longitudinal gas supply holes 35 the ship's bottom to outlet 32 of the end portion in the ship width direction of the plurality of air outlets 32 (longitudinal direction of the ship, the vertical direction of the drawing in FIG. 1 (a)) It is arranged. The chamber refers to a space partitioned for a specific purpose, and in this embodiment, a space provided for the purpose of receiving air supplied from the air supply means and supplying it to the outlet. Is called the first chamber.
With this configuration, the gas supply hole 35 for supplying gas to the air outlets 32 at both ends in the width direction of the ship while keeping the same number of air outlets as the bubble resistance device for reducing frictional resistance of the ship initially examined in the development shown in FIG. The horizontal distance H1 can be reduced. Thereby, in the state inclined to the horizontal direction shown in (c), the water level difference L1 of the gas supply holes 35 at both ends in the ship width direction can be reduced. Further, the horizontal distance H1 between the gas supply holes 35 for supplying gas to the blower outlets 32 at both ends in the ship width direction can be reduced while widening the horizontal width H2 of the blower outlet 32 in the ship width direction. Thereby, the water level difference L1 of the gas supply hole 35 in the state inclined in the horizontal direction can be made smaller than the water level difference L2 of the outlet 32. Therefore, it is possible to suppress the problem that the effect of reducing the frictional resistance of the ship is lowered due to the non-uniform air ejection amount from the gas supply hole 35 due to the water level difference L1.

図2は、本実施形態の船舶の摩擦抵抗低減用気泡吹出装置30の模式図であり、船側から見た断面図(船底が水平な状態)を示している。同図では左側が船舶の船首方向、右側が船尾方向となっている。同図に示すように、船舶の摩擦抵抗低減用気泡吹出装置30の吹出口32は、高さ方向(水深方向)に厚みを有し、後方(船尾方向)に向かうに従って、図中にXで示した厚みが漸減するリセス型である。このため、隔壁36は第1チャンバー34の内側に設けられている。また、吹出口32の気体供給孔35に対向する領域には、当該領域を覆うように被覆板31が設けられている。これにより、気体供給孔35から吹出口32に供給された空気は、吹出口32において海水と混合する際、被覆板31と隔壁36との間及び吹出口32の厚み部分において均一に拡散する。そして、空気は、吹出口32内で均一に拡散した後、吹出口32から船舶の船底11へと供給されることとなる。これにより、吹出口32から供給される空気の幅、すなわち船幅方向における両端の吹出口32の水平距離H2を大きくしたままで、船幅方向における両端の気体供給孔35の水平距離H1を小さくすることができる(図1参照)。したがって、船舶のローリングに起因する気体供給孔35からの空気噴出量の不均一により船舶の摩擦抵抗低減効果が低下するという問題を抑制することが可能となる。   FIG. 2 is a schematic diagram of a bubble blowing device 30 for reducing frictional resistance of a ship according to the present embodiment, and shows a cross-sectional view (a state where the ship bottom is horizontal) viewed from the ship side. In the figure, the left side is the bow direction of the ship and the right side is the stern direction. As shown in the figure, the air outlet 32 of the bubble blowing device 30 for reducing the frictional resistance of the ship has a thickness in the height direction (water depth direction) and is indicated by X in the figure as it goes rearward (stern direction). It is a recess type in which the indicated thickness gradually decreases. Therefore, the partition wall 36 is provided inside the first chamber 34. Further, a covering plate 31 is provided in a region facing the gas supply hole 35 of the air outlet 32 so as to cover the region. Thereby, when the air supplied to the blower outlet 32 from the gas supply hole 35 is mixed with seawater at the blower outlet 32, the air is uniformly diffused between the cover plate 31 and the partition wall 36 and in the thickness portion of the blower outlet 32. The air is uniformly diffused in the air outlet 32, and then supplied from the air outlet 32 to the ship bottom 11 of the ship. Accordingly, the horizontal distance H1 of the gas supply holes 35 at both ends in the ship width direction is decreased while the width of the air supplied from the outlet 32, that is, the horizontal distance H2 of the air outlets 32 at both ends in the ship width direction is increased. (See FIG. 1). Therefore, it is possible to suppress the problem that the effect of reducing the frictional resistance of the ship is lowered due to the nonuniformity of the amount of air jetted from the gas supply hole 35 due to the rolling of the ship.

図3は、図1の船舶の摩擦抵抗低減用気泡吹出装置が配置された船底を船底側から見た状態を示す模式図である。同図に示すように、本実施形態の船舶の摩擦抵抗低減用気泡吹出装置30は、紙面上方向の船首側に設けられている。このように、船舶の摩擦抵抗低減用気泡吹出装置30を船首側に設けることで、吹出口32から吹き出された気泡を船底11に沿って船尾方向に流すことができるから、船舶の進行により船底11に沿って気体を含んだ層を形成することが可能となる。
図4は、船舶の摩擦抵抗低減用気泡吹出装置が船首部における船底の形状に沿って配置された構成を甲板側から見た断面模式図である。同図に示すように、吹出口32を船首部17における船底11の形状に沿って配置された構成とすることとしても良い。なお、図4に示すように、船舶の摩擦抵抗低減用気泡吹出装置30の気体供給孔35には、送気手段13からの空気がじゃま板19を介して供給される構成となっている。この構成により、共通の送気手段13を用いて複数の気体供給孔35に対して、均一に空気を供給することができる。
また、吹出口32から吹き出す気体として、空気を用いる構成について説明したが、摩擦抵抗低減用気泡吹出装置30による気体潤滑に用いられる気体は空気に限られるものではなく、例えば、排気ガスなどを利用することもできる。この点は後述する実施の形態についても同様である。
FIG. 3 is a schematic view showing a state in which the ship bottom in which the bubble blowing device for reducing frictional resistance of the ship of FIG. 1 is arranged is viewed from the ship bottom side. As shown in the figure, the bubble blowing device 30 for reducing the frictional resistance of a ship according to this embodiment is provided on the bow side in the upward direction on the paper. As described above, by providing the bubble blowing device 30 for reducing the frictional resistance of the ship on the bow side, the bubbles blown from the blowout port 32 can flow in the stern direction along the ship bottom 11, so that the ship bottom advances as the ship advances. A layer containing gas can be formed along the line 11.
FIG. 4 is a schematic cross-sectional view of a structure in which a bubble blowing device for reducing frictional resistance of a ship is arranged along the shape of the bottom of a ship at the bow, as viewed from the deck side. As shown in the figure, the air outlet 32 may be arranged along the shape of the bottom 11 of the bow portion 17. As shown in FIG. 4, the air from the air feeding means 13 is supplied to the gas supply hole 35 of the bubble blowing device 30 for reducing the frictional resistance of the ship through the baffle plate 19. With this configuration, air can be uniformly supplied to the plurality of gas supply holes 35 using the common air supply means 13.
Moreover, although the structure using air was demonstrated as the gas which blows off from the blower outlet 32, the gas used for the gas lubrication by the bubble blowing apparatus 30 for frictional resistance reduction is not restricted to air, For example, exhaust gas etc. are utilized. You can also This also applies to the embodiments described later.

上述したリセス型の吹出口32から船底11の後方に向かって噴出される気泡の速度として好ましい範囲を検討するため、下記の実験を行った。
図5は実験に用いたモデルの構造を示す模式図であり、(a)がリセス型の吹出口に相当する構成を側面から見た断面図を、(b)が開口型の吹出口に相当する構成を側面から見た断面図をそれぞれ示している。同図では、左側が船首方向、右側が船尾方向に相当する。
なお、実験上は(a)の方式を後方ジェット方式、(b)の方式を完全開口方式と称している。
図5においては、太線で表した矢印が空気の流れを示しており、(a)では41が被覆板31に相当し、45が気体供給孔35に相当し、42が吹出口32に相当する(図1、図2参照)。また、(b)では気体供給孔35に相当する45の出口側42が吹出口32に相当している。
なお、本実験では、(a)において吹出口32に相当する42の厚みXを2mm、被覆板31に相当する41の長さ(図5の左右方向)を130mmとし、船舶の速度を12kt(ノット)相当とした。
The following experiment was conducted in order to examine a preferable range as the speed of the bubbles ejected from the recess-type outlet 32 toward the rear of the ship bottom 11.
FIG. 5 is a schematic diagram showing the structure of the model used in the experiment, in which (a) is a sectional view of a configuration corresponding to a recess type outlet, and (b) is an opening type outlet. The cross-sectional view which looked at the structure to perform from the side is shown, respectively. In the figure, the left side corresponds to the bow direction and the right side corresponds to the stern direction.
In the experiment, the method (a) is referred to as a rear jet method, and the method (b) is referred to as a complete opening method.
In FIG. 5, arrows indicated by bold lines indicate the flow of air. In (a), 41 corresponds to the cover plate 31, 45 corresponds to the gas supply hole 35, and 42 corresponds to the air outlet 32. (See FIGS. 1 and 2). In (b), 45 outlet sides 42 corresponding to the gas supply holes 35 correspond to the air outlets 32.
In this experiment, in (a), the thickness X of 42 corresponding to the air outlet 32 is 2 mm, the length of 41 corresponding to the covering plate 31 (left-right direction in FIG. 5) is 130 mm, and the speed of the ship is 12 kt ( Knot).

図6は、図5に示したモデルを用いて、供給する空気の量を変化させることにより、吹出口に相当する42からの吹出速度を変化させた場合の抵抗低減効果を示すグラフである。図6のグラフは、縦軸が抵抗低減量(dR)を示しており、横軸が空気相当膜厚(t)を示している。
同図に示すように、上述した実験の結果、後方への空気吹き出し速度は、船速より遅い速度であれば後方ジェット方式(図5(a)参照)と完全開口方式(図5(b)参照)の差が無いこと、船の速度の2倍を超える速度になると後方ジェット方式(図5(a)参照)の抵抗低減効果が低下することが分かった。具体的には、吹き出し速度が船速の1.5倍から2.5倍となる速度において、完全開口方式(図5(b)参照)に対して、抵抗低減量が小さくなっている。このようにリセス型に対応するモデル(いわゆる後方ジェット方式、図5(a)参照)において抵抗低減量が小さくなる理由は、空気吹き出し速度が大きくなると空気吹き出し部の付近にできる空気膜の空気と水の界面に空気膜内の高速の空気流により造波が生じ、生じた波の頂部と船底面とが接触する位置により、抵抗低減量に変化をもたらしているものと推測される。なお、完全開口方式(図5(b)参照)は船速の4倍程度の範囲までは、理想的な抵抗低減量が得られることが別の実験で確認できている。
図6に示す実験結果より、リセス型の吹出口32を用いた場合、吹出口32から船底11の後方に向かって噴出される気泡の速度が船舶の船速の2倍以下となるように調整することにより、船舶の摩擦抵抗低減用気泡吹出装置30の抵抗低減効果を良好なものとすることができる。
また、船舶の航行においては、噴出される気泡の速度を船速に応じて変えることにより、船速が変化した場合であっても抵抗低減効果を良好に維持することができる。
なお、リセス型吹出口を採用する理由は、船のピッチングやスラミングの時に、孔空型吹出口に比較して、気泡の吹き出し速度に対する影響が少ないためである。
FIG. 6 is a graph showing the resistance reduction effect when the blowout speed from 42 corresponding to the blowout port is changed by changing the amount of air to be supplied using the model shown in FIG. In the graph of FIG. 6, the vertical axis represents the resistance reduction amount (dR), and the horizontal axis represents the air equivalent film thickness (t b ).
As shown in the figure, as a result of the above-described experiment, if the air blowing speed to the rear is slower than the ship speed, the rear jet method (see FIG. 5 (a)) and the full opening method (FIG. 5 (b)). It was found that the resistance reduction effect of the rear jet method (see FIG. 5 (a)) deteriorates when there is no difference between the two (see) and when the speed exceeds twice the ship speed. Specifically, the resistance reduction amount is smaller than that of the complete opening method (see FIG. 5B) at a speed at which the blowing speed is 1.5 times to 2.5 times the ship speed. Thus, in the model corresponding to the recess type (so-called backward jet system, see FIG. 5A), the reason why the resistance reduction amount is small is that the air in the air film formed in the vicinity of the air blowing portion when the air blowing speed increases. It is presumed that the wave reduction is caused by the high-speed air flow in the air film at the water interface, and the resistance reduction amount is changed by the position where the top of the generated wave contacts the ship bottom. It has been confirmed in another experiment that the perfect opening method (see FIG. 5B) can provide an ideal resistance reduction amount up to a range of about four times the ship speed.
From the experimental results shown in FIG. 6, when the recess type outlet 32 is used, the speed of the bubbles ejected from the outlet 32 toward the rear of the ship bottom 11 is adjusted to be not more than twice the ship speed. By doing so, the resistance reduction effect of the bubble blowing device 30 for reducing the frictional resistance of the ship can be improved.
Further, in the navigation of a ship, the resistance reduction effect can be satisfactorily maintained even when the ship speed is changed by changing the speed of the jetted bubbles according to the ship speed.
The reason why the recess type air outlet is adopted is that, when pitching or slamming a ship, the influence on the bubble blowing speed is less than that of the hole type air outlet.

(第2の実施形態)
本実施形態の船舶の摩擦抵抗低減用気泡吹出装置は、吹出口あるいは吹出口ブロックが、第1チャンバーに加えて更に第2チャンバーを備えた二重チャンバー構造を備えている点において、第1の実施形態とは異なっている。なお、本実施形態においては、水と気体とを均一に混合・分散する目的のために設けられた空間を第2チャンバーという。また、第1の実施形態において説明した部材と同一の部材には同じ符号を付し、本実施形態では説明を省略する。
(Second Embodiment)
The bubble blowing device for reducing the frictional resistance of a ship according to the present embodiment is the first in that the blowout port or the blowout block has a double chamber structure that further includes a second chamber in addition to the first chamber. This is different from the embodiment. In the present embodiment, a space provided for the purpose of uniformly mixing and dispersing water and gas is referred to as a second chamber. The same members as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted in this embodiment.

図7は、本実施形態の船舶の摩擦抵抗低減用気泡吹出装置50の模式図であり、(a)は船底側から見た平面図を、(b)は船首側から見た断面図を示している。同図に示すように、本実施形態の船舶の摩擦抵抗低減用気泡吹出装置50は、船舶の船底11に複数設けた吹出口52と、送気手段13(図示しないブロワーを含む)から送気される空気を受けて吹出口52に供給する第1チャンバー54を複数備えており、第1チャンバー54と吹出口52との間の隔壁56に、吹出口52への気体供給孔55を複数配置しており、また、吹出口52は、複数の開口57を備えており、開口57を備えた開口板58を海水20との間に備えている。この隔壁56と開口板58により、第2チャンバー59が構成される。   7A and 7B are schematic views of the bubble blowing device 50 for reducing the frictional resistance of a ship according to the present embodiment. FIG. 7A is a plan view seen from the bottom of the ship, and FIG. 7B is a cross-sectional view seen from the bow side. ing. As shown in the figure, a bubble blowing device 50 for reducing frictional resistance of a ship according to the present embodiment supplies air from a plurality of air outlets 52 provided on the ship bottom 11 of the ship and air supply means 13 (including a blower not shown). A plurality of first chambers 54 that receive the air to be supplied and supply the air to the air outlet 52, and a plurality of gas supply holes 55 to the air outlet 52 are arranged in the partition wall 56 between the first chamber 54 and the air outlet 52. In addition, the air outlet 52 includes a plurality of openings 57, and an opening plate 58 including the openings 57 is provided between the seawater 20. The partition 56 and the opening plate 58 constitute a second chamber 59.

図7(a)に示すように、複数の吹出口52のうちの端部の吹出口52へ気体を供給する気体供給孔55は、船底11の長手方向(船舶の前後方向、図7(a)では図面の上下方向)に配置している。また、開口板58の開口57は、船底11側から見たときに、気体供給孔55と重ならない位置に設けられている。これにより、気体供給孔55から供給された空気と開口57から侵入した海水とを、隔壁56と開口板58との間において、効率良く均一に混合することができる。   As shown in FIG. 7 (a), the gas supply hole 55 for supplying gas to the blowout port 52 at the end of the plurality of blowout ports 52 is provided in the longitudinal direction of the ship bottom 11 (the longitudinal direction of the ship, FIG. ) In the vertical direction of the drawing. The opening 57 of the opening plate 58 is provided at a position that does not overlap with the gas supply hole 55 when viewed from the ship bottom 11 side. Thereby, the air supplied from the gas supply hole 55 and the seawater entering through the opening 57 can be efficiently and uniformly mixed between the partition wall 56 and the opening plate 58.

図7に示すように、本実施形態の船舶の摩擦抵抗低減用気泡吹出装置50の吹出口52は、第1チャンバー54に加えて、更に開口57を有する開口板58を備えた第2チャンバー59が設けられている二重チャンバー構造である。このため、気体供給孔55から供給された気体は、第2チャンバー59において、隔壁56と開口板58との間で海水と混合されて空気が均一に分散された後に、開口57から船舶の船底11へと供給されることとなる。この構成により、吹出口52の船幅方向における水平方向幅H2を広くとりながら、船幅方向両端の吹出口52に気体を供給する気体供給孔55の間の水平方向距離H1を小さくすることができる。これにより、横方向に傾いた状態における気体供給孔55の水位差L1(図1参照)を小さくすることができる。したがって、船舶のローリングに起因する気体供給孔55からの空気噴出量の不均一により船舶の摩擦抵抗低減効果が低下するという問題を抑制することが可能となる。   As shown in FIG. 7, the air outlet 52 of the ship frictional resistance reducing bubble blowing device 50 of the present embodiment has a second chamber 59 provided with an opening plate 58 having an opening 57 in addition to the first chamber 54. Is a double chamber structure. For this reason, after the gas supplied from the gas supply hole 55 is mixed with seawater between the partition wall 56 and the opening plate 58 in the second chamber 59 and the air is uniformly dispersed, the bottom of the ship is opened from the opening 57. 11 will be supplied. With this configuration, it is possible to reduce the horizontal distance H1 between the gas supply holes 55 for supplying gas to the air outlets 52 at both ends in the ship width direction while widening the horizontal width H2 in the ship width direction of the air outlets 52. it can. Thereby, the water level difference L1 (refer FIG. 1) of the gas supply hole 55 in the state inclined to the horizontal direction can be made small. Therefore, it is possible to suppress the problem that the effect of reducing the frictional resistance of the ship is lowered due to the nonuniformity of the amount of air jetted from the gas supply hole 55 due to the rolling of the ship.

本実施形態では、吹出口52に板状構造を有し下方に向かって開口57が空いている開口板58を設けることにより、吹出口52が孔空型の吹出口として構成されている。ただし、この構成に限定されるものではなく、吹出口52に網状体により構成されたメッシュ構造の開口板等を用いることにより、吹出口52を孔空型の吹出口以外の構成とすることも可能である。   In this embodiment, the air outlet 52 is configured as a perforated air outlet by providing the air outlet 52 with an opening plate 58 having a plate-like structure and having an opening 57 downward. However, the present invention is not limited to this configuration, and by using a mesh-structured opening plate or the like made of a mesh for the air outlet 52, the air outlet 52 may be configured other than the hole-type air outlet. Is possible.

本実施形態の第1チャンバー54と第2チャンバー59とを備えた二重チャンバー構造の船舶の摩擦抵抗低減用気泡吹出装置50の開口57から船底11の下方に噴出される気泡の好ましい速度を検討するために下記の実験を行った。
図8及び図9は、本実験に用いたモデルの構造を示す模式図であり、図8が断面図、図9が開口板58の構造を示す平面図である。図9に示す開口板58を図8に示す断面の点線で示した位置に装着して実験を行った。
本実験においては、縦(前後方向)12cm、横(左右方向)20cmの開口板58に、開口57として直径3cmの丸孔を図9に示すように横方向のピッチを4cm、縦方向の各列のピッチを4cm、かつ中央列の丸穴を上下列の丸穴とは2cmずらして開け、また、その個数を変更して気泡の下方への噴出速度を調整した。
なお、本実験では、船舶の速度を14kt(ノット)相当として行った。
Examining the preferred velocity of the bubbles ejected from the opening 57 of the bubble blowing device 50 for reducing frictional resistance of a ship having a double chamber structure including the first chamber 54 and the second chamber 59 of the present embodiment to the bottom of the ship bottom 11. In order to do this, the following experiment was conducted.
8 and 9 are schematic views showing the structure of the model used in this experiment, FIG. 8 is a cross-sectional view, and FIG. 9 is a plan view showing the structure of the aperture plate 58. An experiment was conducted by mounting the aperture plate 58 shown in FIG. 9 at the position indicated by the dotted line in the cross section shown in FIG.
In this experiment, a circular hole having a diameter of 3 cm as an opening 57 is formed on an opening plate 58 having a length of 12 cm in the vertical direction (front-rear direction) and 20 cm in the horizontal direction (left-right direction). The pitch of the rows was 4 cm, and the round holes in the center row were shifted by 2 cm from the round holes in the upper and lower rows, and the number of the holes was changed to adjust the downward jetting speed of the bubbles.
In this experiment, the speed of the ship was set at 14 kt (knots).

図10は、図8に示したモデルを用いて、図9に示した開口板58を用いることにより、開口57から船底11の下方に向かって噴出される気泡の速度を変化させた場合の抵抗低減効果を示すグラフである。図10に示したグラフは、縦軸が抵抗低減量(dR)を示しており、横軸が空気相当膜厚(t)を示している。
同図に示すように、下方への空気吹き出し速度を船速と同等とした場合では、開口板58を設けなかったもの(完全開口)と同等の抵抗低減効果を奏している。対して、船速の約2倍とした場合、及び船速の約4倍とした場合では、特に空気相当膜厚(t)が5を越えると抵抗低減効果が低下する。この実験結果より、開口型の吹出口52を用いた場合、吹出口52から船底11の下方に向かって噴出される気泡の速度が船舶の船速の2倍以下となるよう調整することにより、船舶の摩擦抵抗低減用気泡吹出装置50の抵抗低減効果を良好にできることが示されている。
また、船舶の航行においては、噴出される気泡の速度を船速に応じて変えることにより、船速が変化した場合であっても抵抗低減効果を良好に維持することができる。
FIG. 10 shows the resistance when the velocity of bubbles ejected from the opening 57 toward the lower side of the bottom 11 is changed by using the opening plate 58 shown in FIG. 9 by using the model shown in FIG. It is a graph which shows the reduction effect. In the graph shown in FIG. 10, the vertical axis represents the resistance reduction amount (dR), and the horizontal axis represents the air equivalent film thickness (t b ).
As shown in the figure, when the downward air blowing speed is made equal to the ship speed, the resistance reduction effect equivalent to that provided with no opening plate 58 (complete opening) is achieved. On the other hand, when the ship speed is about twice, and when the ship speed is about four times, especially when the air equivalent film thickness (t b ) exceeds 5, the resistance reduction effect decreases. From this experimental result, when the opening-type air outlet 52 is used, by adjusting the speed of the bubbles ejected from the air outlet 52 toward the lower side of the ship bottom 11 to be twice or less the ship speed of the ship, It has been shown that the resistance reduction effect of the bubble blowing device 50 for reducing the frictional resistance of a ship can be improved.
Further, in the navigation of a ship, the resistance reduction effect can be satisfactorily maintained even when the ship speed is changed by changing the speed of the jetted bubbles according to the ship speed.

なお、本実施形態で完全開口方式としない理由は、複数の気体供給孔55を有した吹出口52を用いることにより圧力損失が適度に増し、船のローリングやピッチング時の気泡の噴出量の変動が少なくできるためである。またスラミング時に衝撃圧がチャンバー、空気配管構造に直接作用しないようにし、システムを破損から守るためである。
また、孔空型吹出口を採用する理由は、図6に示すように気泡の吹き出し速度の自由度が高い点と、異物が絡んだ時等において外からのメンテナンスがし易いためである。
Note that the reason for not using the complete opening method in the present embodiment is that the pressure loss is moderately increased by using the air outlet 52 having a plurality of gas supply holes 55, and fluctuations in the amount of bubbles ejected during ship rolling and pitching are achieved. This is because it can be reduced. This is also to prevent impact pressure from acting directly on the chamber and air piping structure during slamming and to protect the system from damage.
The reason why the perforated air outlet is employed is that the degree of freedom of the bubble blowing speed is high as shown in FIG. 6 and that maintenance from the outside is easy when a foreign object is entangled.

(第3の実施形態)
本実施形態の船舶の摩擦抵抗低減用気泡吹出装置は、吹出口がリセス型ではない点において、第1の実施形態と異なっている。なお、第1の実施形態として説明した部材と同一の部材には同じ符号を付し、本実施形態では説明を省略する。
(Third embodiment)
The bubble blowing device for reducing frictional resistance of a ship according to the present embodiment is different from the first embodiment in that the blowout port is not a recess type. In addition, the same code | symbol is attached | subjected to the member same as the member demonstrated as 1st Embodiment, and description is abbreviate | omitted in this embodiment.

図11は、本実施形態の船舶の摩擦抵抗低減用気泡吹出装置60の模式図であり、(a)は船底側から見た平面図を、(b)は船首側から見た断面図(船底が水平な状態)を、(c)は船首側から見た断面図(船底が横方向に傾いた状態)をそれぞれ示している。同図に示すように、本実施形態の船舶の摩擦抵抗低減用気泡吹出装置60は、船舶の船底11に複数設けた吹出口62と、送気手段13(図示しないブロワーを含む)から送気される空気を受けて吹出口62に供給する第1チャンバー64を複数備えており、複数の吹出口62のうち端部の吹出口62の気体供給孔65を船底11の長手方向(船舶の前後方向、(a)では図面の上下方向)に配置している。
この構成により、図14に示した従来の船舶の摩擦抵抗低減用気泡吹出装置と吹出口の数を同じとしながら、船幅方向の両端の吹出口62の気体供給孔65の間の水平距離Hを小さくすることができる。これにより、(c)に示す横方向に傾いた状態において、船幅方向における両端の気体供給孔65の水位差L1を小さくすることができる。したがって、水位差L1に起因して気体供給孔65からの空気噴出量が不均一となることによって船舶の摩擦抵抗低減効果が低下するという問題を抑制することが可能となる。
FIG. 11 is a schematic diagram of a bubble blowing device 60 for reducing frictional resistance of a ship according to the present embodiment, where (a) is a plan view viewed from the ship bottom side, and (b) is a cross-sectional view viewed from the bow side (the ship bottom). (C) shows a cross-sectional view (a state where the bottom of the ship is inclined in the lateral direction) viewed from the bow side. As shown in the figure, a bubble blowing device 60 for reducing frictional resistance of a ship according to the present embodiment supplies air from a plurality of air outlets 62 provided on the ship bottom 11 and air supply means 13 (including a blower not shown). A plurality of first chambers 64 that receive air to be supplied to the outlet 62 are provided, and the gas supply holes 65 of the outlet 62 at the end of the plurality of outlets 62 are arranged in the longitudinal direction of the ship bottom 11 (front and rear of the ship). In the direction (the vertical direction of the drawing in (a)).
With this configuration, the horizontal distance H between the gas supply holes 65 of the air outlets 62 at both ends in the ship width direction is the same as that of the conventional bubble blowing device for reducing frictional resistance of a ship shown in FIG. Can be reduced. Thereby, in the state inclined to the horizontal direction shown in (c), the water level difference L1 of the gas supply holes 65 at both ends in the ship width direction can be reduced. Therefore, it is possible to suppress the problem that the effect of reducing the frictional resistance of the ship is lowered due to the non-uniform air ejection amount from the gas supply hole 65 due to the water level difference L1.

なお、本実施の形態においては、吹出口62には、気体供給孔65が設けられ、第1チャンバー64と吹出口62との間に隔壁66が形成されている。すなわち、吹出口62(表面)と隔壁66は一体的に構成され、この隔壁66により第1チャンバー64が海水20と仕切られている。
また、図11には、吹出口62が板状構造を有し気体供給孔65が下方に向かって空いた孔空型のものを示している。ただし、この構成に限定されるものではなく、吹出口62として網状体により構成されたメッシュ構造のもの等を用いることも可能である。
In the present embodiment, the air outlet 62 is provided with a gas supply hole 65, and a partition wall 66 is formed between the first chamber 64 and the air outlet 62. That is, the air outlet 62 (surface) and the partition wall 66 are integrally formed, and the first chamber 64 is partitioned from the seawater 20 by the partition wall 66.
Further, FIG. 11 shows a perforated type in which the air outlet 62 has a plate-like structure and the gas supply hole 65 is open downward. However, it is not limited to this configuration, and it is also possible to use a mesh structure having a mesh structure or the like as the outlet 62.

(第4の実施形態)
本実施形態は、船舶の船底に設けた複数の吹出口を有した吹出口ブロックを備えたものとして船舶の摩擦抵抗低減用気泡吹出装置を実施する場合について説明する。なお、本実施形態では、第1の実施形態として説明したリセス型の吹出口を備えた吹出しブロックについて説明するが、他の構成の吹出口を備えた吹出しブロックを用いた場合も同様の効果を奏することができる。また、第1〜第3の実施形態として説明した部材と同一の部材には同じ符号を付して、本実施形態では説明を省略する。
(Fourth embodiment)
This embodiment demonstrates the case where the bubble blowing apparatus for reducing the frictional resistance of a ship is implemented as a thing provided with the blower outlet block provided with the several blower outlet provided in the ship bottom of the ship. In addition, although this embodiment demonstrates the blowout block provided with the recess type blower outlet demonstrated as 1st Embodiment, the same effect is also obtained when the blowout block provided with the blower outlet of another structure is used. Can play. The same members as those described as the first to third embodiments are denoted by the same reference numerals, and description thereof is omitted in this embodiment.

図12は、船舶の摩擦抵抗低減用気泡吹出装置を構成する吹出口ブロック70の構成の概略を示す模式図である。同図に示すように、吹出口ブロック70は、複数の吹出口32へ一つの第1チャンバー34からブロックとして送気手段73(図示しないブロワーを含む)により空気を送る構成のものである。そして、吹出口ブロック70の船幅方向における両端の吹出口32に対して気体を供給する気体供給孔35を、船底11(図13参照)の長手方向(図12では上下方向)に並ぶように配置している。この構成により、図12中に二点鎖線Cで示した吹出口ブロック70の前後中心線寄りに、気体供給孔35を配置することができる。したがって、吹出口32の船幅方向における水平方向幅H2を広くとりながら、船幅方向両端の吹出口32に気体を供給する気体供給孔35の間の水平方向距離H1を小さくすることができる。これにより、横方向に傾いた状態における気体供給孔35の水位差L1(図1参照)を小さくすることができる。したがって、船舶のローリングに起因する気体供給孔35からの空気噴出量の不均一により船舶の摩擦抵抗低減効果が低下するという問題を抑制することが可能となる。   FIG. 12 is a schematic diagram showing an outline of the configuration of the air outlet block 70 that constitutes the bubble blowing device for reducing the frictional resistance of a ship. As shown in the figure, the air outlet block 70 is configured to send air to a plurality of air outlets 32 from one first chamber 34 as a block by an air supply means 73 (including a blower not shown). And the gas supply hole 35 which supplies gas with respect to the blower outlet 32 of the both ends in the ship width direction of the blower outlet block 70 is arranged in the longitudinal direction (FIG. 12 up-down direction) of the ship bottom 11 (refer FIG. 13). It is arranged. With this configuration, the gas supply hole 35 can be disposed near the front and rear center lines of the outlet block 70 indicated by a two-dot chain line C in FIG. Accordingly, the horizontal distance H1 between the gas supply holes 35 for supplying gas to the blower outlets 32 at both ends in the ship width direction can be reduced while widening the horizontal width H2 of the blower outlet 32 in the ship width direction. Thereby, the water level difference L1 (refer FIG. 1) of the gas supply hole 35 in the state inclined to the horizontal direction can be made small. Therefore, it is possible to suppress the problem that the effect of reducing the frictional resistance of the ship is lowered due to the nonuniformity of the amount of air jetted from the gas supply hole 35 due to the rolling of the ship.

図13は、本実施形態の摩擦抵抗低減用気泡吹出装置を船底側から見た模式図である。同図に示すように、本実施形態の船舶の摩擦抵抗低減用気泡吹出装置80は、複数の吹出口ブロック70を船底11に設け、吹出口ブロック70に対して送気される気体を独立して調節する送気制御手段74をさらに備えた構成となっている。このように送気制御手段74により、気体供給源75から送気手段73を介して送付する気体を吹出口ブロック70毎に調節することが可能となる。   FIG. 13 is a schematic view of the bubble blowing device for reducing frictional resistance according to the present embodiment as viewed from the bottom of the ship. As shown in the figure, the bubble blowing device 80 for reducing the frictional resistance of a ship according to the present embodiment is provided with a plurality of outlet blocks 70 on the ship bottom 11, and the gas supplied to the outlet block 70 is independent. The air supply control means 74 for adjusting the air flow is further provided. As described above, the gas supplied from the gas supply source 75 through the air supply means 73 can be adjusted by the air supply control means 74 for each outlet block 70.

送気制御手段74は、気体供給源75を共通とする場合には、例えばバルブやダンパーを用いて実現することができる。ただし、送気制御手段74はこれに限定されるものではなく、吹出口ブロック70毎に気体供給源75を設け、気体供給源75を制御することにより、各吹出口ブロック70へ送られる気体を制御しても良い。また、これらを組み合わせることにより送気制御手段74を構成することとしても良い。   When the gas supply source 75 is shared, the air supply control means 74 can be realized using, for example, a valve or a damper. However, the air supply control means 74 is not limited to this, and a gas supply source 75 is provided for each outlet block 70 and the gas supplied to each outlet block 70 is controlled by controlling the gas supply source 75. You may control. Further, the air supply control means 74 may be configured by combining these.

本発明は、空気等を用いた気体潤滑法による船舶の摩擦抵抗低減効果がローリングに起因して低下することを抑制するための装置として利用することができる。   INDUSTRIAL APPLICABILITY The present invention can be used as an apparatus for suppressing a reduction in ship frictional resistance reduction effect due to rolling by a gas lubrication method using air or the like.

11 船底
13、63、73 送気手段
17 船首部
32、52、62 吹出口
34、54 64 第1チャンバー
35、55、65 気体供給孔
36、56、66 隔壁
30、50、60、80 船舶の摩擦抵抗低減用気泡吹出装置
59 第2チャンバー
70 吹出口ブロック
74 送気制御手段
11 Ship bottom 13, 63, 73 Air supply means 17 Bow 32, 52, 62 Air outlet 34, 54 64 First chamber 35, 55, 65 Gas supply hole 36, 56, 66 Bulkhead 30, 50, 60, 80 Ship Bubble blowing device 59 for reducing frictional resistance 59 Second chamber 70 Air outlet block 74 Air supply control means

Claims (10)

船舶の周囲に気泡を噴出し摩擦抵抗を低減する摩擦抵抗低減用気泡吹出装置において、
前記船舶の船底に複数設けた吹出口と、送気手段から送気される気体を受けて前記吹出口に供給するチャンバーとを備え、前記チャンバーと前記吹出口の間の隔壁に前記吹出口への気体供給孔を複数配置するとともに、複数の前記吹出口のうち、端部の前記吹出口への複数の前記気体供給孔の全てを前記船底の長手方向かつ前記船舶の前後中心線寄りに配置したことを特徴とする船舶の摩擦抵抗低減用気泡吹出装置。
In the bubble blowing device for reducing frictional resistance that blows out bubbles around the ship and reduces frictional resistance,
A plurality of air outlets provided on the bottom of the ship; and a chamber that receives gas supplied from an air supply means and supplies the gas to the air outlets, and a partition wall between the chamber and the air outlets to the air outlets. The plurality of gas supply holes are arranged, and among the plurality of outlets , all of the plurality of gas supply holes to the outlet at the end are arranged in the longitudinal direction of the ship bottom and near the front-rear center line of the ship. A bubble blowing device for reducing the frictional resistance of a ship characterized by the above.
船舶の周囲に気泡を噴出し摩擦抵抗を低減する摩擦抵抗低減用気泡吹出装置において、
前記船舶の船底に設けた複数の吹出口を有した吹出口ブロックと、送気手段から送気される気体を受け前記吹出口ブロックに供給するチャンバーとを備え、前記チャンバーと前記吹出口の間の隔壁に前記吹出口への気体供給孔を複数配置するとともに、複数の前記吹出口のうち、端部の前記吹出口への複数の前記気体供給孔の全てを前記船底の長手方向かつ前記吹出口ブロックの前後中心線寄りに配置したことを特徴とする船舶の摩擦抵抗低減用気泡吹出装置。
In the bubble blowing device for reducing frictional resistance that blows out bubbles around the ship and reduces frictional resistance,
A blower outlet block having a plurality of blower outlets provided on the bottom of the ship; and a chamber that receives gas supplied from an air supply means and supplies the gas to the blower outlet block, between the chamber and the blower outlet. as well as of arranging a plurality of gas supply holes to the partition wall to said outlet, among the plurality of the air outlets, all of the plurality of the gas supply holes to the outlet end of the ship bottom longitudinal and the blowing A bubble blowing device for reducing frictional resistance of a ship, wherein the bubble blowing device is disposed near a front and rear center line of an outlet block .
複数の前記吹出口ブロックを前記船底に設け、複数の前記吹出口ブロックに対して送気される前記気体を独立して調節する送気制御手段をさらに備えたことを特徴とする請求項2に記載の船舶の摩擦抵抗低減用気泡吹出装置。   3. The air supply control means according to claim 2, further comprising: a plurality of the air outlet blocks provided on the bottom of the ship, and the air supply control means for independently adjusting the gas supplied to the air outlet blocks. The bubble blowing device for reducing the frictional resistance of the vessel described. 前記吹出口が、高さ方向に厚みを有し後方に向かうに従い前記厚みが漸減するリセス型であることを特徴とする請求項1から請求項3のうちの1項に記載の船舶の摩擦抵抗低減用気泡吹出装置。   4. The ship's frictional resistance according to claim 1, wherein the air outlet is a recess type having a thickness in a height direction and gradually decreasing the thickness toward a rear side. 5. Bubble blowing device for reduction. 前記吹出口から前記船底の後方に向かって噴出される前記気泡の速度が前記船舶の船速の2倍以下であることを特徴とする請求項4に記載の船舶の摩擦抵抗低減用気泡吹出装置。   The bubble blowing device for reducing the frictional resistance of a ship according to claim 4, wherein the speed of the bubbles blown out from the outlet toward the rear of the ship bottom is twice or less the ship speed of the ship. . 前記吹出口が板状構造を有し、気体噴出孔が下方に向かって空いた孔空型であることを特徴とする請求項1から請求項3のうちの1項に記載の船舶の摩擦抵抗低減用気泡吹出装置。   4. The ship's frictional resistance according to claim 1, wherein the air outlet has a plate-like structure and is a perforated type in which a gas ejection hole is open downward. 5. Bubble blowing device for reduction. 前記吹出口あるいは前記吹出口ブロックが二重チャンバー構造であることを特徴とする請求項1から請求項3のうちの1項に記載の船舶の摩擦抵抗低減用気泡吹出装置。   The bubble blowing device for reducing frictional resistance of a ship according to any one of claims 1 to 3, wherein the blowout port or the blowout block has a double chamber structure. 前記吹出口から前記船底の下方に向かって噴出される前記気泡の速度を、前記船舶の船速と同等以下としたことを特徴とする請求項7に記載の船舶の摩擦抵抗低減用気泡吹出装置。   The bubble blowing device for reducing the frictional resistance of a ship according to claim 7, wherein the speed of the bubbles blown out from the outlet toward the bottom of the ship bottom is equal to or less than the ship speed of the ship. . 噴出される前記気泡の前記速度を前記船速に応じて変えたことを特徴とする請求項5あるいは請求項8に記載の船舶の摩擦抵抗低減用気泡吹出装置。   The bubble blowing device for reducing frictional resistance of a ship according to claim 5 or 8, wherein the speed of the bubbles to be ejected is changed according to the ship speed. 前記吹出口あるいは前記吹出口ブロックを船首部における前記船底の形状に沿って配置したことを特徴とする請求項1から請求項9のうちの1項に記載の船舶の摩擦抵抗低減用気泡吹出装置。   10. The bubble blowing device for reducing frictional resistance of a ship according to claim 1, wherein the air outlet or the air outlet block is arranged along a shape of the ship bottom at a bow portion. .
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