CN111905941B - Control method of fan-shaped spray flow field - Google Patents
Control method of fan-shaped spray flow field Download PDFInfo
- Publication number
- CN111905941B CN111905941B CN202010788932.2A CN202010788932A CN111905941B CN 111905941 B CN111905941 B CN 111905941B CN 202010788932 A CN202010788932 A CN 202010788932A CN 111905941 B CN111905941 B CN 111905941B
- Authority
- CN
- China
- Prior art keywords
- flow
- section
- jet
- nozzle
- axis
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000007921 spray Substances 0.000 title claims abstract description 64
- 238000000034 method Methods 0.000 title claims abstract description 35
- 239000007788 liquid Substances 0.000 claims abstract description 59
- 238000005315 distribution function Methods 0.000 claims abstract description 31
- 238000004401 flow injection analysis Methods 0.000 claims description 22
- 238000002347 injection Methods 0.000 claims description 15
- 239000007924 injection Substances 0.000 claims description 15
- 239000011159 matrix material Substances 0.000 claims description 15
- 230000004907 flux Effects 0.000 claims description 12
- 230000008859 change Effects 0.000 claims description 9
- 238000012360 testing method Methods 0.000 claims description 9
- 230000033228 biological regulation Effects 0.000 claims description 5
- 230000007423 decrease Effects 0.000 claims description 3
- 230000003247 decreasing effect Effects 0.000 claims description 3
- 230000008569 process Effects 0.000 claims description 3
- 230000009467 reduction Effects 0.000 claims description 2
- 238000005507 spraying Methods 0.000 description 18
- 238000010586 diagram Methods 0.000 description 10
- 238000004364 calculation method Methods 0.000 description 6
- 239000011148 porous material Substances 0.000 description 5
- 230000009471 action Effects 0.000 description 3
- 206010069747 Burkholderia mallei infection Diseases 0.000 description 2
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- IXPNQXFRVYWDDI-UHFFFAOYSA-N 1-methyl-2,4-dioxo-1,3-diazinane-5-carboximidamide Chemical compound CN1CC(C(N)=N)C(=O)NC1=O IXPNQXFRVYWDDI-UHFFFAOYSA-N 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000005562 fading Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 230000002262 irrigation Effects 0.000 description 1
- 238000003973 irrigation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 235000010413 sodium alginate Nutrition 0.000 description 1
- 229940005550 sodium alginate Drugs 0.000 description 1
- 239000000661 sodium alginate Substances 0.000 description 1
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 1
- 235000017557 sodium bicarbonate Nutrition 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B1/00—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
- B05B1/30—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to control volume of flow, e.g. with adjustable passages
- B05B1/3006—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to control volume of flow, e.g. with adjustable passages the controlling element being actuated by the pressure of the fluid to be sprayed
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B1/00—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
- B05B1/02—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to produce a jet, spray, or other discharge of particular shape or nature, e.g. in single drops, or having an outlet of particular shape
- B05B1/04—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to produce a jet, spray, or other discharge of particular shape or nature, e.g. in single drops, or having an outlet of particular shape in flat form, e.g. fan-like, sheet-like
Landscapes
- Application Of Or Painting With Fluid Materials (AREA)
Abstract
Hair brushThe invention relates to a control method of a fan-shaped spray flow field, which specifically comprises the following steps: (1) initially setting parameters of a flow field of a nozzle when the nozzle sprays liquid under gas-liquid pressure and flow: z is a radical of0、zn、3σ(0,z0)、
c(0)、h(z0) K; (2) calculating the spray flow field distribution: in the jet fundamental section, the spatial flow intensity distribution function is as follows:
wherein Q (r, theta, z) is a spatial flow intensity distribution function of any point in the basic segment of the flow field; (3) comparing the spatial flow intensity distribution to a desired flow intensity; (4) adjusting the spatial flow intensity distribution: the nozzle is replaced firstly, then the rotating angle of the nozzle around the x axis, the y axis and the z axis is rotated, and finally the gas-liquid pressure and the flow of the nozzle inlet are increased or reduced until the difference between the space flow intensity distribution and the expected flow intensity distribution meets the following requirements:
and n is the number of the small cubes.
Description
Technical Field
The invention relates to the field of liquid coating, in particular to control of a fan-shaped nozzle spray flow field.
Background
The atomization spraying is widely applied to the industries of automobile industry, wood product processing industry, irrigation and the like. In recent years, due to the demand for personalized customization, spray coating is increasingly applied to objects such as home ornaments, clothing materials, posters, and the like. Because the structure difference of the nozzles is large, under the action of different pressures and flows, different liquid sprays different spray flow fields, and the difficulty is brought to the combined layout of the multiple nozzles. At present, most enterprises improve the distribution uniformity of the liquid applying amount on the sprayed object by continuously adjusting the pressure and the flow passing through the inlet of the nozzle, the relative position between the nozzle and the sprayed object and the relative position between the nozzle and the nozzle. With the continuous improvement of the spraying requirements, only by knowing the mathematical expression of the spatial distribution of the flow field under the specific spraying process condition, the basis can be provided for the multi-nozzle combination layout, and the convenience is provided for the online control of the spray liquid amount.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a control method of a fan-shaped spray flow field; the method specifically establishes nozzle flow distribution by deducing a fan-shaped nozzle plane flow distribution function and a space flow distribution function, is suitable for calculating spray flow fields of fan-shaped nozzles, circular nozzles and the like, provides a mathematical basis for nozzle pressure control, flow control and multi-nozzle combination layout, and provides possibility for realizing uniform spraying.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a control method of a fan-shaped spray flow field comprises the following steps:
(1) the flow field parameters when the nozzle is initially set to spray liquid under gas-liquid pressure and flow (extreme values of pressure and flow are determined by hydraulic pipelines, nozzle structures and spray volume requirements) (a proper nozzle is selected according to the viscosity difference of the liquid; the nozzle is properly selected, and the liquid can be atomized into small liquid drops under the action of pressure) are as follows:
z0the distance from the beginning of the jet basic section to the nozzle;
znthe distance from the termination of the jet basic section to the jet orifice;
z＝z0on the cross section, in the effective jet area of the flow, the ellipse major semiaxis is 3 sigma (0, z)0)；
z＝z0On the cross section, in the effective flow injection area, the elliptical short semi-axis
c (0), the azimuth angle theta is 0 degree, and the slope of the outline of the flow field along the positive direction of the z axis;
z＝z0on the cross-section, through the center of the cross-section
Flow intensity value h (z) of0)；
k, the intensity of the flux in the central axis of the jet is along the z-axis (i.e. the axial direction of the central axis of the jet, above "z ═ z0"representing" a displacement in the z-axis
z0") an anti-fading coefficient;
z0、zn、σ(0,z0)、
c(0)、h(z0) The k value is related to the structure of the nozzle, the gas-liquid pressure, the flow rate, the speed and the mass ratio of the nozzle, the components, the viscosity, the density, the surface tension and other properties of the liquid; the sprayed liquid passes through the nozzle outlet under the action of certain gas and liquid pressure and can be divided into a jet flow initial section, a jet flow basic section and a jet flow dissipation section. Wherein, the stability of the initial section of the jet flow is poor, and the industrial use value is not available; the jet dissipation section is far away from the nozzle, and the jet dynamic pressure of the jet dissipation section is difficult to meet the required requirement; the flow field in the jet flow basic section is stable, the sprayed liquid is atomized uniformly, and an atomized layer and surrounding air have obvious limits, so that the method has practical application significance;
(2) calculating the spray flow field distribution: (the calculation of each nozzle is the same in the multi-nozzle flow field, the flow of different nozzles needs to be superposed numerically) in the jet basic section, the polar function formula of the space flow intensity distribution function is as follows:
q (r, theta, z) is a spatial flow intensity distribution function of any point in a basic segment of the flow field, and all symbols such as r, theta, z and the like have the same meanings as the symbols in the basic segment; namely a spray flow field distribution function, 7 flow field parameters of the nozzle under specific gas-liquid pressure and flow and when spraying specific liquid are measured and then substituted into the formula to obtain the spray flow field distribution;
(3) comparing the difference of the spatial flow intensity distribution function with the expected flow intensity:
in the jet basic section, dividing a flow effective injection area into n small cubes (the value of n is determined according to the calculation precision requirement, and n takes a larger value when the calculation precision requirement is higher); calculating the flow intensity Q of the center positions of all the cubesc(r, θ, z), the set of which is denoted QcNamely: qc＝{Qc(r1,θ1,z1),Qc(r2,θ2,z2),...,Qc(rn,θn,zn) }; let the expected flow intensity at the center of all the cubes be Qt(r, θ, z), the set of which is denoted QtNamely: qt＝{Qt(r1,θ1,z1),Qt(r2,θ2,z2),...,Qt(rn,θn,zn)}；
If the flow intensity QcAnd QtSatisfies the following conditions:
then the control of the fan-shaped spray flow field is finished; otherwise, adjusting the spatial flow intensity distribution until the control of the fan-shaped spray flow field is finished;
the adjusting the spatial flow intensity distribution refers to:
(1) the nozzle replacement specifically comprises:
(1.1) when the expected flow field is circular, selecting a circular nozzle; when the desired flow field is elliptical, selecting a fan nozzle;
(1.2) adjustment of the circular nozzle or the fan nozzle, a series of the nozzles can be recorded in advance in a tableThe ratio of the length half shaft and the minor half shaft of the nozzle flow field with different outlet shapes inquires the corresponding nozzle model according to the ratio of the length half shaft and the minor half shaft of the expected flow field until the basic section of the jet flow, wherein z is equal to zxIn cross section ("z ═ zx"means" a value on the z-axis of the central axis of the jet of zx", that is zxIs the center of the cross section passing through the z-axis
Distance from the origin P of the z-axis (satisfying z)0≤zx≤zn) The position P is the center of the outlet of the spray head; z isxThe section' refers to any plane along the z axis), the proportion of the length of the flow field and the half axis of the short half axis of the space flow intensity distribution in the effective flow injection area is
The ratio of the desired flow field length to the half-axis of the desired flow field length is
Satisfies the following conditions:
wherein, acFlow field length semiaxis, b, representing spatial flow intensity distributioncFlow field minor semiaxis, a, representing spatial flow intensity distributiontThe longer half-axis representing the desired flow field, btA minor semi-axis representing the desired flow field;
the spraying requirements are different, different types of nozzles are selected, and when the liquid with different attributes is sprayed, liquid incidence parameters such as pressure, speed, flow, gas-liquid mass ratio and the like at the inlet of the nozzle are adjusted accordingly. The gas-liquid pressure and flow parameters are below the maximum working pressure and maximum flow allowed by the nozzle.
The liquid to be sprayed is not limited to water, and spraying liquids with different components, such as pigments, chemical reagents and the like, are selected according to different sprayed objects. The liquid has large differences in properties such as viscosity and surface tension. When the liquid properties are susceptible to temperature, changes in the liquid properties also affect the spatial flow intensity of the spray flow field.
After the nozzle is adjusted to meet the requirements, the difference between the spatial flow intensity distribution function and the expected flow intensity can be compared for one time, and if the difference requirements of the spatial flow intensity distribution function and the expected flow intensity are met, the fan-shaped spray flow field can be controlled without further adjustment; if not, continuing to adjust:
(2) taking a point P of an outlet of the nozzle as a rotation center, rotating the rotation angle of the nozzle around the x, y and z axes, namely, the sequence of regulation around a rotating shaft is z → y → x in turn, until the flow field of space flow intensity distribution is the same as the direction of the expected flow field in the effective flow injection area in the jet flow basic section; when the rotation angles of the adjusting nozzles around the x, y and z axes meet the requirements, the difference between the spatial flow intensity distribution function and the expected flow intensity can be compared for one time, and if the difference requirements of the spatial flow intensity distribution function and the expected flow intensity are met, further adjustment is not needed, and the control of the fan-shaped spray flow field is completed; if not, continuing to adjust:
(3) and increasing or decreasing the gas-liquid pressure and the flow rate of the nozzle inlet until the difference between the space flow rate intensity distribution and the expected flow rate intensity distribution meets the requirement.
As a preferred technical scheme:
in the method for controlling a fan-shaped spray flow field, the rotation angles of the rotating nozzle around the x, y and z axes are calculated as follows:
(1) the spatial position of the desired flow field may be represented by a 3 x 3 matrix B, and associated with the local axis x of the nozzlei、yi、ziParallel, and of equal size and in the same direction, i.e.
The spatial position of the flow field with the spatial flow intensity distribution is
Two by two orthogonal and the determinant value is 1, then A-1＝AT；
(2) Let the rotation matrix R, let B equal AR, then R equal A-1B；
(3) According to A-1＝ATR is A-1B＝ATB, then:
the spatial position A can be obtained by directly reading a position value by installing an attitude sensor on the spray head, and the spatial position B is given by an expected position;
(4) setting the corresponding adjusting angles as gamma, beta and alpha according to the sequence of adjusting around the rotating shaft as z → y → x; the rotation matrix R is then:
wherein R isz-y-xA space rotation matrix is formed by sequentially rotating around the axes z, y and x by adopting a right-hand coordinate system; rotz, Rot y and Rot x are basic rotation matrixes formed after rotating gamma, beta and alpha around z, y and x axes respectively;
(5) a is to beTB is associated with the matrix R to solve for γ, β, α, i.e. the nozzle can be adjusted from the spatial position a to the spatial position B by rotating the nozzle in sequence γ around the z-axis, β around the y-axis, and α around the x-axis.
The geometric parameter z is the control method of the fan-shaped spray flow field0、zn、σ(0,z0)、
And c (0) calibrating the relation between the image pixels and the actual size by using a 50mm fixed-focus lens camera, and calculating and obtaining the image from the shot flow field image.
A method of controlling a fan-shaped spray flow field as described above, h (z)0) And k belongs to a flow field mechanics-like parameter, measured using a pitot tube.
The method for controlling the fan-shaped spray flow field comprises the following specific steps of:
(2.1) establishing a plane polar coordinate system to obtain a polar coordinate function formula of the plane flow intensity function;
randomly intercepting a jet flow section vertical to the axis of the jet flow beam at the jet flow basic section to obtain a plane flow intensity function in any direction in the jet flow section and a function formula of the plane flow intensity function in a plane polar coordinate system; wherein the geometric center of the cross section is
The distance from the geometric center of the cross section to the nozzle is zx(means geometric center of cross section)
Distance to nozzle outlet center P), and z)0≤zx≤zn；
Geometric center of cross section
The angle between any straight line and the positive direction of the x-axis (i.e. the azimuth angle of the straight line) is theta (theta belongs to 0, pi)]) (ii) a On this straight line, the jet flow intensity distribution conforms to the normal distribution law, and the flow intensity function is:
wherein e is Euler number, and the value is about 2.71828; Γ is the magnification of the flow intensity function; mu is the mathematical expectation in probability statistics, with the mathematical meaning of f (mu) ═ f (m)]max(ii) a Although σ is the flow intensity variance ("σ" represents the flow intensity variance, "σ" is different from the aforementioned "3 σ law" in units of σ), the distance z from the center of the cross section to the nozzle is taken according to the normal distribution 3 σ law since the two are numerically related and the same sign is used in probability)xAnd the azimuth angle theta are related to each other,record as
m, theta are parameters, and the following relation exists between coordinate variables x and y in the jet section:
the relation between the parameter variable and the coordinate variable is utilized to rewrite the flow intensity function into a form under a plane polar coordinate system, and then the point is passed
And the polar coordinate functional formula of the plane flow intensity function of any point on a straight line which forms theta with the positive direction of the x axis is as follows:
(2.2) correcting a polar coordinate function formula of the plane flow intensity function after uniqueness test and nonnegativity test;
in a plane polar coordinate system, in order to ensure that the flow intensity value of each point in the jet flow basic segment has uniqueness and nonnegativity, a polar coordinate function formula of a plane flow intensity function needs to be corrected as follows:
wherein,
the method is characterized in that a plane flow intensity function is corrected by uniqueness and nonnegativity test of any point on a section under a plane polar coordinate system;
is the geometric center of the cross section
The flow intensity value of (a) is constant for a certain plane;
is that
Minimum value in the variable value range of the variable satisfies
(2.3) determining the section boundary of the jet flow by adopting a 3 sigma rule, and perfecting a polar coordinate function formula of a plane flow intensity function;
extracting a contour boundary in a basic section of the jet flow field according to the change rate of the size of the effective jet area of the flow field on different sections along the z-axis;
the flow intensity distribution shape on any jet section in the jet basic section can be regarded as an ellipsograph taking the jet axis as the center, and the ellipsograph can be regarded as passing through the center
The flow intensity ray is formed by rotating flow intensity rays with different lengths; from (2.1), the flux intensity distribution on the ray is in accordance with the normal distribution, and according to the 3 σ rule, any point on the boundary of the ellipse reaches the geometric center of the section
A distance of
Then
Can be expressed as:
wherein,
each is z ═ zxWith major and minor semiaxes of the ellipse in the cross-section of the flow injection zone
And is
After the 3 sigma rule is adopted, the effective injection area is considered, and the value range of r in the plane flow intensity function is limited. The polar function of the planar flow intensity function after the flow boundary is defined is:
wherein,
the method is characterized in that a plane flow intensity distribution function in an effective injection area is obtained by examining uniqueness and nonnegativity of any point on a section in a plane polar coordinate system; r is the distance from any point on the cross section to the geometric center of the cross section (r)max＝3σ(θ))；
(2.4) in the jet basic section, the elliptical shapes of the effective injection areas of the cross sections at different positions from the nozzle are similar, and the width of the effective injection areas of the cross sections linearly increases along the positive direction of the z axis, namely:
wherein c (theta) is the change rate of the width of the cross-section effective injection area along the z-axis and is related to the azimuth angle theta;
is z ═ z0Variance of flow intensity distribution on straight lines at different angles from the positive direction of the x-axis in cross section, and σ (θ, z)0) Have the same meaning, i.e. have
Is popularized to any cross section in the jet basic section and has sigmaz(θ)＝σ(θ,z)。
Extracting z ═ z0In the cross section, the variance σ (0, z) of the flow intensity distribution in the major and minor semiaxes of the ellipse of the effective flow ejection region0)、
And when the azimuth angle theta is 0 degrees, the slope c (0) of the flow field outer contour along the positive direction of the z axis is obtained, and the change rate c (theta) of the effective flow injection area on any azimuth angle theta is obtained:
wherein c (0), σ (0, z)0)、
All related to the nozzle structure, the gas-liquid pressure and its ratio at the nozzle inlet, the viscosity of the liquid, the density of the liquid and the surface tension of the liquid.
(2.5) obtaining a flow intensity function on the central axis of the jet flow according to the attenuation rule of the central flow intensity of the jet flow along the z axis, and further obtaining a spatial flow intensity distribution function; the jet center flow intensity decreases in a hyperbolic curve along the z-axis, namely:
wherein, the larger the k value is, the slower the decay speed of the flux intensity of the central axis of the jet along the z axis is; the smaller the k value is, the faster the decay speed of the flux intensity of the central axis of the jet along the z axis is;
Qz(0, theta) represents the intensity function of the flow at the azimuth angle theta on a section perpendicular to the z-axis and passing through the central axis of the jet, written in the form of Q (0, theta, z), abbreviated as hzOr h (z), i.e. Qz(0,θ)＝Q(0,θ,z)＝hzH (z); then passing through the central axis of the jet, where z is z0On a cross section, the flow intensity function at the azimuth angle theta is
Namely, the method comprises the following steps:
polar function formula of plane flow intensity function after combination (2.3) flow boundary definition
The polar coordinate function formula of the jet space flow intensity distribution function is as follows:
in the method for controlling the fan-shaped spray flow field, the reduction of the gas-liquid pressure and the flow at the inlet of the nozzle means Qc-Qt≥1×10-3When the jet flow basic section is adopted, the gas-liquid pressure and the flow of the nozzle inlet are reduced at the same time, and then the flow intensity set Q at the central position of each small square body of the effective flow injection area in the jet flow basic section is obtainedcDecrease; the increase of the gas-liquid pressure and the flow rate at the inlet of the nozzle refers to Qc-Qt＜1×10-3When the gas-liquid pressure and the flow of the nozzle inlet are simultaneously increased, the flow intensity set Q at the central position of each small cube of the effective flow injection area in the basic jet flow section is obtainedcAnd is increased.
Advantageous effects
(1) The invention relates to a control method of a fan-shaped nozzle spray flow field, which obtains a spray flow field space flow intensity distribution function by comprehensively considering plane flow intensity distribution, uniqueness and nonnegativity of flow function values and attenuation rules of jet flow central flow intensity on different sections and different azimuth angles in a jet flow basic section;
(2) according to the control method of the fan-shaped nozzle spray flow field, a spatial flow intensity distribution function of the nozzle under specific spray parameters can be obtained only by measuring 7 undetermined coefficients related to the structure of the nozzle, the gas-liquid pressure, the flow, the speed and the mass ratio of the nozzle and the liquid properties;
(3) according to the control method of the fan-shaped nozzle spray flow field, the nozzle flow distribution is established by deducing the fan-shaped nozzle plane flow intensity distribution function and the space flow intensity distribution function, and the method is suitable for calculating the fan-shaped nozzle and the circular nozzle flow field;
(4) provides mathematical basis for nozzle pressure control, flow control and nozzle layout optimization, and provides possibility for realizing uniform spraying.
Drawings
FIG. 1 is a schematic view of a nozzle flow field;
FIG. 2 is a schematic diagram of the flow intensity distribution of the jet flow in any section of the basic section; wherein, (a) is the position information of the jet basic segment, and (b) is a flow intensity distribution diagram in any direction in the section A-A;
FIG. 3 is a schematic diagram of a major semi-axis and a minor semi-axis of an ellipse in an effective flow injection area on any jet flow section perpendicular to an axis z-axis of a jet flow beam in a jet flow basic section shown in FIGS. 1-2;
FIG. 4 is a schematic diagram of geometric-like constant determination; wherein, (a) is a geometric constant determination schematic diagram corresponding to the minor semiaxis of the ellipse, and (b) is a geometric constant determination schematic diagram corresponding to the major semiaxis of the ellipse;
FIG. 5 is a schematic diagram of flow field mechanics-like constant determination using a pitot tube; wherein, 1-spray head, 2-slide rail, 3-slide block, 4-pitot tube, 5-orifice plate;
FIG. 6 shows a nozzle with a distance from the spraying surfaceWhen the outlet is 0.4m and the axes x, y and z of the axial lead of the nozzle rotate 20 degrees at the same time, the initial flow field distribution pattern on the spraying surface is obtained; wherein, 7 constants of the flow field are initially set as: z is a radical of0＝0.15m；zn＝0.4m；3σ(0,z0)＝0.12m，
c(0)＝0.3；k＝1；h(z0)＝100L/(s*m2)；
FIG. 7 is a graph of the flow field across the nozzle face after varying some of the parameters of FIG. 6, where (a) is a change in only the length-to-semi-axis ratio, i.e., 3 σ (0, z)0)＝0.15m，
A flow field distribution pattern on a corresponding spray receiving surface, (b) a flow field distribution pattern on the corresponding spray receiving surface when only the initial slope of the outer contour is changed, namely c (0) ═ 0.5, (c) a flow field distribution pattern on the corresponding spray receiving surface when only the central axis flow strong anti-attenuation coefficient is changed, namely k ═ 0.5, and (d) a flow field distribution pattern on the corresponding spray receiving surface when only the initial flow intensity of the central axis is changed, namely h (z) (z0)＝85L/(s*m2) And (4) distributing the flow field on the corresponding spraying surface.
Detailed Description
The invention will be further illustrated with reference to specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.
A control method of a fan-shaped spray flow field comprises the following steps:
(1) the flow field sprayed by the spray head is non-submerged free jet, and can be roughly divided into an initial section, a basic section and a dissipation section (as shown in figure 1), and the schematic diagram of the flow intensity distribution of any section of the jet basic section is shown in figure 2; wherein, (a) is the position information of the jet basic segment, and (b) is a flow intensity distribution diagram in any direction in the section A-A; under a plane polar coordinate system, a schematic diagram of the geometric dimension of an effective injection region of a cross-section A-A flow field is shown in FIG. 3;
(2) calculating the spray flow field distribution:
(2.1) establishing a plane polar coordinate system to obtain a plane flow intensity function;
randomly intercepting a jet flow section vertical to the axis of the jet flow beam at the jet flow basic section to obtain a plane flow intensity function in any direction in the jet flow section and a function formula of the plane flow intensity function in a plane polar coordinate system; wherein the geometric center of the cross section is
The distance from the center of the cross section to the nozzle is zxAnd z is0≤zx≤zn；
Geometric center of cross section
The angle between any straight line and the positive direction of the x-axis (i.e. the azimuth angle of the straight line) is theta (theta belongs to 0, pi)]) (ii) a On this straight line, the jet flow intensity distribution conforms to the normal distribution law, and the flow intensity function is:
wherein e is Euler number, and the value is about 2.71828; Γ is the magnification of the flow intensity function; mu is the mathematical expectation in probability statistics, with the mathematical meaning of f (mu) ═ f (m)]max(ii) a Sigma is the variance of the flow intensity, and the value is taken as the distance z from the geometric center of the cross section to the nozzlexAnd the azimuth angle theta are related and recorded as
m, theta are parameters, and the following relation exists between coordinate variables x and y in the jet section:
by using the relationship between the parameter variable and the coordinate variable, the flow intensity function is rewritten into a form under a plane polar coordinate system, and then the plane flow intensity function is:
(2.2) correcting the plane flow intensity function after uniqueness test and nonnegativity test;
in a plane polar coordinate system, in order to ensure that the flow intensity value of each point in the jet basic segment has uniqueness and nonnegativity, the plane flow intensity function needs to be corrected as follows:
in the formula,
the method is characterized in that a plane flow intensity function is corrected by uniqueness and nonnegativity test of any point on a section under a plane polar coordinate system;
is the geometric center of the cross section
A flow intensity value of (d);
is that
Minimum value in the variable value range of the variable satisfies
(2.3) determining the section boundary of the jet flow by adopting a 3 sigma rule, and perfecting a plane flow intensity function;
in the jet basic section, the flow intensity distribution shape on any jet section can be regarded as an ellipsoid with the jet axis as the center, and any point on the boundary of the ellipse to the geometric center of the section
A distance of
Then
Can be expressed as:
wherein,
each is z ═ zxWith major and minor semiaxes of the ellipse in the cross-section of the flow injection zone
And is
The planar flow intensity function after the flow boundary definition is:
wherein,
is that any point on the cross section is on the plane poleIn a coordinate system, after uniqueness and nonnegativity inspection, a plane flow intensity distribution function in an effective injection area; r is the distance from any point on the section to the geometric center of the section, and the maximum value rmax＝3σ(θ)；
(2.4) in the jet basic section, the elliptical shapes of the effective injection areas of the cross sections at different positions from the nozzle are similar, and the width of the effective injection areas of the cross sections linearly increases along the positive direction of the z axis, namely:
wherein c (theta) is the change rate of the width of the cross-section effective injection area along the z-axis and is related to the azimuth angle theta;
is z ═ z0Variance of flow intensity distribution on straight lines at different angles from the positive direction of the x-axis in cross section, and σ (θ, z)0) Have the same meaning, i.e. have
σz(θ)＝σ(θ,z)。
Extracting z ═ z0In the cross section, the variance σ (0, z) of the flow intensity distribution in the major and minor semiaxes of the ellipse of the effective flow ejection region0)、
And when the azimuth angle theta is 0 degrees, the slope c (0) of the flow field outer contour along the positive direction of the z axis is obtained, and the change rate c (theta) of the effective flow injection area on any azimuth angle theta is obtained:
wherein c (0), σ (0, z)0)、
All related to the nozzle structure, the gas-liquid pressure and its ratio at the nozzle inlet, the viscosity of the liquid, the density of the liquid and the surface tension of the liquid.
(2.5) obtaining a flow intensity function on the central axis of the jet flow according to the attenuation rule of the central flow intensity of the jet flow along the z axis, and further obtaining a spatial flow intensity distribution function; the jet center flow intensity decreases in a hyperbolic curve along the z-axis, namely:
wherein, the larger the k value is, the slower the decay speed of the flux intensity of the central axis of the jet along the z axis is; the smaller the k value is, the faster the decay speed of the flux intensity of the central axis of the jet along the z axis is;
Qz(0, theta) represents the intensity function of the flow at the azimuth angle theta on a section perpendicular to the z-axis and passing through the central axis of the jet, written in the form of Q (0, theta, z), abbreviated as hzOr h (z), i.e. Qz(0,θ)＝Q(0,θ,z)＝hzH (z); then passing through the central axis of the jet, where z is z0On a cross section, the flow intensity function at the azimuth angle theta is
Namely, the method comprises the following steps:
in combination with (2.3)
Then the spatial flux intensity distribution function is obtained as:
wherein Q (r, theta, z) is a spatial flow intensity distribution function of any point in the basic section of the flow field.
Applying the space flow intensity distribution function to a case, namely adopting a Japanese Mingmiao A-100 pneumatic atomizing nozzle; initial parameters of the nozzle were set as: the distance between the outlet and the sprayed surface is 0.4m, and the axes x, y and z of the axial lead of the nozzle rotate 20 degrees simultaneously; the air inlet pressure of the nozzle is 0.3MPa, and the liquid path pressure is 0.2 MPa; the liquid formula is a mixed solution (the viscosity of the mixed solution is 620CP at normal temperature) of 2.0 wt% of sodium alginate, 5.0 wt% of urea, 2.0 wt% of sodium bicarbonate and 91.0 wt% of water for controlling a spray flow field; the specific process is as follows:
(1) after the relation between the image pixel and the actual size is calibrated by using a 50mm fixed-focus lens camera, z is obtained by calculation from the shot flow field image0、znAnd
the measurement principle is shown in fig. 4 (a); after the relation between the image pixel and the actual size is calibrated by using a 50mm fixed-focus lens camera, sigma (0, z) is obtained by calculation from the shot flow field image0) And c (0), the measurement principle of which is shown in FIG. 4 (b); determination of h (z) Using a Pitot tube0) And k, as shown in fig. 5, the spray head 1 is vertically fixed, a pore plate 5 capable of sliding up and down is placed below the spray head, an opening in the pore plate is positioned at the geometric center of the pore plate, so that the pore plate is fixedly connected with the sliding block 3, and the slide rail 2 is provided with scale marks, so that the vertical distance between the current pore plate and the spray head outlet can be accurately known. The interface of the pitot tube 4 is inserted into the inner hole of the orifice plate, and the opening direction of the orifice is opposite to the z axis. At z0Measuring the flow intensity at the center of the cross section to obtain a value h (z)0). Then, z is added0And znThe flow intensity is divided into 5 equal parts, the flow intensity is measured at each equal division point, the relation between the flow intensity and the axial distance of the jet flow is drawn into discrete points in a rectangular coordinate system, and a hyperbolic function is used for fitting the image, so that the anti-attenuation coefficient k can be obtained.
The specific parameters are as follows:
z00.15m, which is the distance from the beginning of the jet basic section to the nozzle;
zn0.4m, is a jetThe distance from the termination of the base segment to the spout;
z＝z0on the cross section, in the effective jet area of the flow, the ellipse major semiaxis is 3 sigma (0, z)0)＝0.12m；
z＝z0On the cross section, in the effective flow injection area, the elliptical short semi-axis
At the azimuth angle theta of 0 DEG, the slope c (0) of the flow field outer contour along the positive direction of the z axis is 0.3;
z＝z0on cross section, through the geometric centre O of the cross sectionz0Flow intensity value h (z) of0)＝100L/(s*m2)；
The anti-attenuation coefficient k of the flux intensity of the central axis of the jet flow along the z axis is 1;
further determining the initial flow field distribution on the sprayed surface as shown in FIG. 6;
when the above parameters are adjusted, the flow field distribution on the corresponding spray receiving surface changes, as shown in fig. 7, wherein (a) is to change only the ratio of the length to the minor axis, i.e., 3 σ (0, z)0)＝0.15m，
A flow field distribution pattern on a corresponding spray receiving surface, (b) a flow field distribution pattern on the corresponding spray receiving surface when only the initial slope of the outer contour is changed, namely c (0) ═ 0.5, (c) a flow field distribution pattern on the corresponding spray receiving surface when only the central axis flow strong anti-attenuation coefficient is changed, namely k ═ 0.5, and (d) a flow field distribution pattern on the corresponding spray receiving surface when only the initial flow intensity of the central axis is changed, namely h (z) (z0)＝85L/(s*m2) And (4) distributing the flow field on the corresponding spraying surface.
(2) Comparing the difference of the spatial flow intensity distribution with the expected flow intensity:
in the basic section of the jet, z ═ zxOn the cross section, dividing the effective flow injection area into n small cubes; when the spraying object is an automobile or a fabric, the spraying requirement is high, and the value of n is more than 100; when the spraying object is a building, the value of n is 50-100; the spraying object is a machineWhen the device is used for a rack, the spraying requirement is general, and n is 10-50; calculating the flow intensity Q of the center positions of all the cubesc(r, θ, z), the set of which is denoted QcNamely: qc＝{Qc(r1,θ1,z1),Qc(r2,θ2,z2),...,Qc(rn,θn,zn) }; let the expected flow intensity at the center of all the cubes be Qt(r, θ, z), the set of which is denoted QtNamely: qt＝{Qt(r1,θ1,z1),Qt(r2,θ2,z2),...,Qt(rn,θn,zn)}；
If the flow intensity QcAnd QtSatisfies the following conditions:
then, the difference between the spatial flow intensity distribution and the expected flow intensity distribution does not meet the requirement;
(3) the spatial flow intensity distribution needs to be adjusted:
(3.1) replacing the nozzle, specifically:
(3.1.1) when the desired flow field is circular, selecting a circular nozzle; when the desired flow field is elliptical, selecting a fan nozzle;
(3.1.2) adjusting the circular nozzle or the fan-shaped nozzle, recording the ratio of the length of the flow field and the minor axis of a series of nozzles with different outlet shapes by using a table in advance, inquiring the corresponding nozzle model according to the ratio of the length of the flow field and the minor axis of the expected flow field until the jet basic section is reached, wherein the value of z is equal to zxOn the cross section, in the effective flow jet area, the ratio of the length of the flow field and the short half shaft of the space flow intensity distribution is
The ratio of the desired flow field length to the half-axis of the desired flow field length is
Satisfies the following conditions:
wherein, acFlow field length semiaxis, b, representing spatial flow intensity distributioncFlow field minor semiaxis, a, representing spatial flow intensity distributiontThe longer half-axis representing the desired flow field, btA minor semi-axis representing the desired flow field;
after the nozzle is adjusted to meet the requirements, the difference between the spatial flow intensity distribution function and the expected flow intensity can be compared for one time, and if the difference requirements of the spatial flow intensity distribution function and the expected flow intensity are met, the fan-shaped spray flow field can be controlled without further adjustment; if not, continuing to adjust:
(3.2) the rotation angle of the rotating flow field around the x, y and z axes, i.e. the sequence of the regulation around the rotation axis is z → y → x, until in the jet basic segment, where z is zxOn the cross section, in the effective flow injection area, the flow field length and the short half shaft of the space flow intensity distribution are respectively parallel to the expected flow field length and the short half shaft;
the calculation method of the rotation angle of the rotary nozzle around the x, y and z axes is as follows:
(3.2.1) the spatial position of the desired flow field can be represented by a 3 x 3 matrix B with the local coordinate axis x of the nozzlei、yi、ziParallel, and of equal size and in the same direction, i.e.
The spatial position of the flow field with the spatial flow intensity distribution is
Then A is-1＝AT；
(3.2.2) setting the rotation matrix R such that B is AR, then R is a-1B；
(3.2.3) according to A-1＝ATR is A-1B＝ATB, then:
the spatial position A can be obtained by installing an attitude sensor on the spray head, and the spatial position B is given by an expected position;
(3.2.4) setting the sequence of regulation around the rotating shaft as z → y → x, and setting the corresponding regulation angles as gamma, beta and alpha; the rotation matrix R is then:
wherein R isz-y-xA space rotation matrix is formed by sequentially rotating around the axes z, y and x by adopting a right-hand coordinate system; rotz, Rot y and Rot x are basic rotation matrixes formed after rotating gamma, beta and alpha around z, y and x axes respectively;
(3.2.5) adding ATB is combined with the matrix R to solve gamma, beta and alpha, namely the nozzle can be adjusted from the space position A to the space position B by rotating gamma, beta and alpha around the z axis, y axis and x axis in sequence;
when the rotation angles of the adjusting nozzles around the x, y and z axes meet the requirements, the difference between the spatial flow intensity distribution and the expected flow intensity can be compared for one time, and if the difference requirements of the spatial flow intensity distribution and the expected flow intensity are met, further adjustment is not needed, and the control of the fan-shaped spray flow field is completed; if not, continuing to adjust:
(3.3) increasing or decreasing the gas-liquid pressure and flow rate at the nozzle inlet:
when Q isc-Qt＜1×10-3When the jet flow intensity is in the basic section, the flow intensity set Q at the central position of each small cube of the effective flow injection area is obtainedcIncreasing until the difference between the spatial flow intensity distribution and the expected flow intensity distribution meets the requirement;
when Q isc-Qt≥1×10-3When the jet flow intensity is in the basic section of the jet flow, the gas-liquid pressure and the flow of the inlet of the nozzle are reduced at the same time, and the flow intensity set Q at the central position of each small cube of the effective flow injection area in the basic section of the jet flowcReducing until the difference between the spatial flow intensity distribution and the expected flow intensity distribution meets the requirement;
the satisfying requirement means the flow intensity QcAnd Qt：
the control of the fan-shaped spray flow field is completed.
Claims (6)
1. A control method of a fan-shaped spray flow field is characterized by comprising the following steps:
(1) initially setting the nozzle under gas-liquid pressure and flow, and setting the parameters of a flow field when the nozzle sprays liquid as follows:
z0the distance from the beginning of the jet basic section to the nozzle;
znthe distance from the termination of the jet basic section to the jet orifice;
z＝z0on the cross section, in the effective jet area of the flow, the ellipse major semiaxis is 3 sigma (0, z)0)；
z＝z0On the cross section, in the effective flow injection area, the elliptical short semi-axis
c (0), the azimuth angle theta is 0 degree, and the slope of the outline of the flow field along the positive direction of the z axis;
z＝z0on the cross section, passing through the center O of the cross sectionz0Flow intensity value h (z) of0)；
k, the anti-attenuation coefficient of the flux intensity of the central axis of the jet along the z-axis;
(2) calculating the spray flow field distribution: in the jet fundamental section, the spatial flow intensity distribution function is as follows:
wherein Q (r, theta, z) is a spatial flow intensity distribution function of any point in the basic segment of the flow field; r is the distance from any point on the section to the geometric center of the section;
(3) comparing the difference of the spatial flow intensity distribution with the expected flow intensity:
in the jet basic section, dividing the effective flow injection area into n small cubes; calculating the flow intensity Q of the center positions of all the cubesc(r, θ, z), the set of which is denoted QcNamely: qc＝{Qc(r1,θ1,z1),Qc(r2,θ2,z2),...,Qc(rn,θn,zn) }; let the expected flow intensity at the center of all the cubes be Qt(r, θ, z), the set of which is denoted QtNamely: qt＝{Qt(r1,θ1,z1),Qt(r2,θ2,z2),...,Qt(rn,θn,zn)}；
If the flow intensity QcAnd QtSatisfies the following conditions:
then the control of the fan-shaped spray flow field is finished; otherwise, adjusting the spatial flow intensity distribution until the control of the fan-shaped spray flow field is finished;
the adjusting the spatial flow intensity distribution refers to:
(1) the nozzle replacement specifically comprises:
(1.1) when the expected flow field is circular, selecting a circular nozzle; when the desired flow field is elliptical, selecting a fan nozzle;
(1.2) adjusting the circular nozzle or the fan-shaped nozzle until the jet flow is in the basic section, wherein z is equal to zxOn the cross section, in the effective flow jet area, the ratio of the length of the flow field and the short half shaft of the space flow intensity distribution is
The ratio of the desired flow field length to the half-axis of the desired flow field length is
Satisfies the following conditions:
wherein, acFlow field length semiaxis, b, representing spatial flow intensity distributioncFlow field minor semiaxis, a, representing spatial flow intensity distributiontThe longer half-axis representing the desired flow field, btA minor semi-axis representing the desired flow field;
(2) rotating angles of the rotating nozzle around x, y and z axes, namely the sequence of regulation around the rotating shaft is z → y → x in sequence, until the flow field of space flow intensity distribution is the same as the direction of the expected flow field in the effective flow injection area in the jet flow basic section;
(3) and increasing or decreasing the gas-liquid pressure and the flow rate of the nozzle inlet until the difference between the space flow rate intensity distribution and the expected flow rate intensity distribution meets the requirement.
2. The method as claimed in claim 1, wherein the rotation angle of the rotating nozzle around the x, y and z axes is calculated as follows:
(1) the spatial position of the desired flow field may be represented by a 3 x 3 matrix B, and associated with the local axis x of the nozzlei、yi、ziParallel, and of equal size and in the same direction, i.e.
The spatial position of the flow field with the spatial flow intensity distribution is
Then A is-1＝AT；
(2) Let the rotation matrix R, let B equal AR, then R equal A-1B；
(3) According to A-1＝ATR is A-1B＝ATB, then:
the spatial position A can be obtained by installing an attitude sensor on the spray head, and the spatial position B is given by an expected position;
(4) setting the corresponding adjusting angles as gamma, beta and alpha according to the sequence of adjusting around the rotating shaft as z → y → x; the rotation matrix R is then:
wherein R isz-y-xA space rotation matrix is formed by sequentially rotating around the axes z, y and x by adopting a right-hand coordinate system; rot z, Rot y and Rotx are basic rotation matrixes formed after rotating gamma, beta and alpha around z, y and x axes respectively;
(5) a is to beTB is associated with the matrix R to solve for γ, β, α, i.e. the nozzle can be adjusted from the spatial position a to the spatial position B by rotating the nozzle in sequence γ around the z-axis, β around the y-axis, and α around the x-axis.
3. The method of claim 1, wherein z is the number of steps of the method0、zn、σ(0,z0)、
And c (0) calibrating the relation between the image pixels and the actual size by using a 50mm fixed-focus lens camera, and calculating and obtaining the image from the shot flow field image.
4. The method of claim 1, wherein h (z) is the control of the fan spray flow field0) And k was measured using a pitot tube.
5. The method for controlling the fan-shaped spray flow field according to claim 1, wherein the specific process of calculating the distribution of the spray flow field comprises:
(2.1) establishing a plane polar coordinate system to obtain a plane flow intensity function;
randomly intercepting a jet flow section vertical to the axis of the jet flow beam at the jet flow basic section to obtain a plane flow intensity function in any direction in the jet flow section and a function formula of the plane flow intensity function in a plane polar coordinate system; wherein the geometric center of the cross section is OzxThe distance from the geometric center of the cross section to the nozzle is zxAnd z is0≤zx≤zn；
Geometric center of cross section OzxThe angle between any straight line and the positive direction of the x axis, namely the azimuth angle of the straight line is theta (theta belongs to 0 and pi)]) (ii) a On this straight line, the jet flow intensity distribution conforms to the normal distribution law, and the flow intensity function is:
wherein e is Euler number, and the value is about 2.71828; Γ is the magnification of the flow intensity function; mu is the mathematical expectation in probability statistics, with the mathematical meaning of f (mu) ═ f (m)]max(ii) a Sigma is the variance of the flow intensity, and the value is taken from the distance z from the center of the section to the nozzlexAnd the azimuth angle theta are related and recorded as
m, theta are parameters, and the following relation exists between coordinate variables x and y in the jet section:
by using the relationship between the parameter variable and the coordinate variable, the flow intensity function is rewritten into a form under a plane polar coordinate system, and then the plane flow intensity function is:
(2.2) correcting the plane flow intensity function after uniqueness test and nonnegativity test;
in a plane polar coordinate system, in order to ensure that the flow intensity value of each point in the jet basic segment has uniqueness and nonnegativity, the plane flow intensity function needs to be corrected as follows:
wherein,
the method is characterized in that a plane flow intensity function is corrected by uniqueness and nonnegativity test of any point on a section under a plane polar coordinate system;
is the geometric center of the cross section
A flow intensity value of (d);
is that
Minimum value in the variable value range of the variable satisfies
(2.3) determining the section boundary of the jet flow by adopting a 3 sigma rule, and perfecting a plane flow intensity function;
in the jet basic section, the flow intensity distribution shape on any jet section can be regarded as an ellipsoid with the jet axis as the center, and any point on the boundary of the ellipse to the geometric center of the section
A distance of
Then
Can be expressed as:
wherein,
each is z ═ zxWith major and minor semiaxes of the ellipse in the cross-section of the flow injection zone
And is
The planar flow intensity function after the flow boundary definition is:
wherein,
the method is characterized in that a plane flow intensity distribution function in an effective injection area is obtained by examining uniqueness and nonnegativity of any point on a section in a plane polar coordinate system; r is the distance from any point on the section to the geometric center of the section, and the maximum value rmax＝3σ(θ)；
(2.4) in the jet basic section, the elliptical shapes of the effective injection areas of the cross sections at different positions from the nozzle are similar, and the width of the effective injection areas of the cross sections linearly increases along the positive direction of the z axis, namely:
wherein c (theta) is the change rate of the width of the cross-section effective injection area along the z-axis and is related to the azimuth angle theta;
is z ═ z0Variance of flow intensity distribution on straight lines at different angles from the positive direction of the x-axis in cross section, and σ (θ, z)0) Have the same meaning, i.e. have
σz(θ)＝σ(θ,z)；
Extracting z ═ z0In the cross section, the variance σ (0, z) of the flow intensity distribution in the major and minor semiaxes of the ellipse of the effective flow ejection region0)、
And when the azimuth angle theta is 0 degrees, the slope c (0) of the flow field outer contour along the positive direction of the z axis is obtained, and the change rate c (theta) of the effective flow injection area on any azimuth angle theta is obtained:
wherein c (0), σ (0, z)0)、
All related to the structure of the nozzle, the gas-liquid pressure and the ratio of the gas-liquid pressure at the inlet of the nozzle, the viscosity of the liquid, the density of the liquid and the surface tension of the liquid;
(2.5) obtaining a flow intensity function on the central axis of the jet flow according to the attenuation rule of the central flow intensity of the jet flow along the z axis, and further obtaining a spatial flow intensity distribution function; the jet center flow intensity decreases in a hyperbolic curve along the z-axis, namely:
wherein, the larger the k value is, the slower the decay speed of the flux intensity of the central axis of the jet along the z axis is; the smaller the k value is, the faster the decay speed of the flux intensity of the central axis of the jet along the z axis is;
Qz(0, theta) represents the intensity function of the flow at the azimuth angle theta on a section perpendicular to the z-axis and passing through the central axis of the jet, written in the form of Q (0, theta, z), abbreviated as hzOr h (z), i.e. Qz(0,θ)＝Q(0,θ,z)＝hzH (z); then passing through the central axis of the jet, where z is z0On a cross section, the flow intensity function at the azimuth angle theta is
Namely, the method comprises the following steps:
in combination with (2.3)
The spatial flux intensity distribution function is:
6. the method as claimed in claim 1, wherein the reduction of the gas-liquid pressure and flow rate at the nozzle inlet is defined as Qc-Qt≥1×10-3When the jet flow basic section is adopted, the gas-liquid pressure and the flow of the nozzle inlet are reduced at the same time, and then the flow intensity set Q at the central position of each small square body of the effective flow injection area in the jet flow basic section is obtainedcDecrease; the increase of the gas-liquid pressure and the flow rate at the inlet of the nozzle refers to Qc-Qt<1×10-3When the gas-liquid pressure and the flow of the nozzle inlet are simultaneously increased, the flow intensity set Q at the central position of each small cube of the effective flow injection area in the basic jet flow section is obtainedcAnd is increased.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010788932.2A CN111905941B (en) | 2020-08-07 | 2020-08-07 | Control method of fan-shaped spray flow field |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010788932.2A CN111905941B (en) | 2020-08-07 | 2020-08-07 | Control method of fan-shaped spray flow field |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111905941A CN111905941A (en) | 2020-11-10 |
| CN111905941B true CN111905941B (en) | 2021-06-04 |
Family
ID=73283281
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010788932.2A Active CN111905941B (en) | 2020-08-07 | 2020-08-07 | Control method of fan-shaped spray flow field |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111905941B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115228317B (en) * | 2022-07-05 | 2024-04-26 | 中国农业科学院烟草研究所(中国烟草总公司青州烟草研究所) | Fertilizer and pesticide preparation device and method for flue-cured tobacco planting |
| CN116920739B (en) * | 2023-03-02 | 2024-06-14 | 福建省龙德新能源有限公司 | Liquid circulation atomization synthesis control system and method for lithium hexafluorophosphate preparation |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02268854A (en) * | 1989-04-10 | 1990-11-02 | Miyoshi Nakagawa | Thermal spraying device |
| EP1046426A2 (en) * | 1999-04-22 | 2000-10-25 | Lechler GmbH & Co.KG | High pressure spray nozzle |
| US6823833B2 (en) * | 2000-07-03 | 2004-11-30 | Combustion Dymanics Corp. | Swirl injector for internal combustion engine |
| CN104324861A (en) * | 2014-08-12 | 2015-02-04 | 清华大学 | Multi-parameter time-varying robot spraying method |
| WO2016140682A1 (en) * | 2015-03-05 | 2016-09-09 | Axalta Coating Systems Ip Co., Llc | Spray gun with high transfer efficiency and method for use thereof |
| CN207430544U (en) * | 2017-11-10 | 2018-06-01 | 中国农业大学 | A kind of Fan spray head of bore automatic adjustment |
| CN109332033A (en) * | 2018-11-13 | 2019-02-15 | 江苏大学 | A kind of electrostatic coating machine people is directed to the optimization method of non-regulation planar polygon layer thickness uniformity |
-
2020
- 2020-08-07 CN CN202010788932.2A patent/CN111905941B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02268854A (en) * | 1989-04-10 | 1990-11-02 | Miyoshi Nakagawa | Thermal spraying device |
| EP1046426A2 (en) * | 1999-04-22 | 2000-10-25 | Lechler GmbH & Co.KG | High pressure spray nozzle |
| US6823833B2 (en) * | 2000-07-03 | 2004-11-30 | Combustion Dymanics Corp. | Swirl injector for internal combustion engine |
| CN104324861A (en) * | 2014-08-12 | 2015-02-04 | 清华大学 | Multi-parameter time-varying robot spraying method |
| WO2016140682A1 (en) * | 2015-03-05 | 2016-09-09 | Axalta Coating Systems Ip Co., Llc | Spray gun with high transfer efficiency and method for use thereof |
| CN207430544U (en) * | 2017-11-10 | 2018-06-01 | 中国农业大学 | A kind of Fan spray head of bore automatic adjustment |
| CN109332033A (en) * | 2018-11-13 | 2019-02-15 | 江苏大学 | A kind of electrostatic coating machine people is directed to the optimization method of non-regulation planar polygon layer thickness uniformity |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111905941A (en) | 2020-11-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111905941B (en) | Control method of fan-shaped spray flow field | |
| CN104324861B (en) | A kind of multiparameter time-varying Control During Paint Spraying by Robot method | |
| CN105327949B (en) | A kind of flow control methods of hot steel strip coiling temperature | |
| CN109909092A (en) | Paint film spraying method based on the detection of film thickness real non-destructive | |
| CN106546036A (en) | Flow dividing head, air conditioner and adjusting method of air conditioner | |
| DE102013211873A1 (en) | Method for determining the acceleration uniformity of a coated surface | |
| CN109093619B (en) | Robot track planning method for uniform thermal spraying of curved surface | |
| CN111898308A (en) | Design scheme for optimizing air nozzle of paint spray gun by using response surface method | |
| CA2839925A1 (en) | Coating nozzle for high-viscosity paint | |
| CN108829960B (en) | Numerical simulation method for powder flow field of coaxial powder feeding nozzle manufactured by laser additive remanufacturing | |
| CN115046722B (en) | Method for calibrating mach number of cross-supersonic-velocity wind tunnel nozzle | |
| CN117884338A (en) | Paint thickness control method and system for double-spiral superposition spraying of inner wall of cylinder | |
| CN111298998A (en) | Method for optimizing rotation angle of outlet of atomizing nozzle | |
| US6168824B1 (en) | Paint viscosity measuring system | |
| JP2008036625A (en) | Method for deciding atomization parameter for controlling coating atomizer using atomizing medium | |
| CN106735028A (en) | Produce the arrangement of nozzles method and system of the conticaster of Hot Metal in Beam Blank | |
| CN111495633B (en) | Coating closed-loop supply system based on Faster-rcnn and control method | |
| CN111468326A (en) | PID control method and coating closed-loop supply system | |
| CN109201749A (en) | Hot rolling low temperature coiling band steel surface based on temperature purges control method | |
| JPH06296923A (en) | Method for adjusting coating film thickness by gas wiping | |
| CN209452509U (en) | It is a kind of to determine angle water ring for copper pipe production | |
| CN113569500A (en) | Droplet ejection forming ejection state and droplet deposition size prediction method | |
| CN117019596B (en) | Automatic spraying and positioning method for plastic packaging bottle | |
| JP4304958B2 (en) | Coating apparatus and die slit thickness control method | |
| EP0810501B1 (en) | Method for determining and reducing the pulsation degree for a pneumatic transport |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |