EP0623786A1 - Combustion chamber - Google Patents

Abstract

In a combustion chamber, a gaseous or liquid fuel is sprayed as a secondary flow into a gaseous, channelled main flow. The main flow is passed over vortex generators (9), of which several are arranged next to one another over the width or the periphery of the channel (20) through which the flow passes. The height (h) of the vortex generators is at least 50% of the height (H) of the channel through which the flow passes or of the channel part allocated to the vortex generator. The secondary flow is directed into the channel (20) in the immediate area of the vortex generators (9). With the novel static mixer, longitudinal vortices without a recirculation zone are generated in the channel through which the flow passes. Exceptionally short mixing distances with at the same time little pressure loss are thus achieved in the combustion chamber. <IMAGE>

Description

Technical field

The invention relates to a combustion chamber in which a gaseous or liquid fuel is injected as a secondary flow into a gaseous, channeled main flow, the secondary flow having a substantially smaller mass flow than the main flow.

State of the art

In the combustion chamber there can be cold streaks in the main flow, for example caused by the introduction of cooling air into the combustion air. Such strands can lead to insufficient burnout in the combustion zone. Measures must therefore be taken to mix combustion air, cooling air and fuel intimately.

A delta wing that is employed in a channelized flow can be regarded as a vortex generator in the broadest sense. If such wings are flown from the tip, a dead water area is created on the one hand downstream of the wing, and on the other hand the flow through the employed surface experiences a not inconsiderable drop in pressure. The arrangement of such a delta wing in a channel must be carried out using flow-restricting aids such as struts, ribs or the like. Furthermore result there are problems with the cooling of such elements, for example in a hot gas flow.

Such delta wings cannot be used as mixing elements of two or more flows. The mixing of a secondary flow with a main flow present in a channel usually takes place by radial injection of the secondary flow into the channel. The momentum of the secondary flow is so small, however, that an almost complete mixing only takes place after a distance of approx. 100 channel heights.

Presentation of the invention

The invention is therefore based on the object of providing a combustion chamber of the type mentioned at the outset with a device with which longitudinal vortices can be generated in the channel through which flow occurs without a recirculation area.

According to the invention, this is achieved in that the main flow is conducted via vortex generators, of which several are arranged next to one another over the width or the circumference of the flow-through channel, preferably without gaps, and the height of which is at least 50% of the height of the flow-through channel or that Vortex generator associated channel part, and that the secondary flow is introduced into the channel in the immediate area of the vortex generators.

With the new static mixer, which is represented by the 3-dimensional vortex generators, it is possible to achieve extremely short mixing distances in the combustion chamber with a low pressure drop. A coarse mixing of the two streams takes place after only one full vortex revolution, while a fine mixing as a result of turbulent Flow and molecular diffusion processes exist after a distance that corresponds to a few channel heights.

• dass er drei frei umströmte Flächen aufweist, die sich in Strömungsrichtung erstrecken und von denen eine die Dachfläche und die beiden andern die Seitenflächen bilden,
• dass die Seitenflächen mit einer gleichen Kanalwand bündig sind und miteinander den Pfeilwinkel α einschliessen,
• dass die Dachfläche mit einer quer zum durchströmten Kanal verlaufenden Kante an der gleichen Kanalwand anliegt wie die Seitenwände,
• und dass die längsgerichteten Kanten der Dachfläche, die bündig sind mit den in den Strömungskanal hineinragenden längsgerichteten Kanten der Seitenflächen unter einem Anstellwinkel Θ zur Kanalwand verlaufen.

A vortex generator is characterized by

• that it has three freely flowing surfaces which extend in the direction of flow and one of which forms the roof surface and the other two the side surfaces,
• that the side surfaces are flush with the same duct wall and include the arrow angle α with one another,
• that the roof surface rests on the same channel wall as the side walls with an edge running transversely to the flow channel,
• and that the longitudinal edges of the roof surface, which are flush with the longitudinal edges of the side surfaces protruding into the flow channel, extend at an angle of attack Θ to the channel wall.

The advantage of such an element can be seen in its particular simplicity in every respect. In terms of production technology, the element consisting of three walls with flow around it is completely problem-free. The roof surface can be joined with the two side surfaces in a variety of ways. The element can also be fixed to flat or curved channel walls in the case of weldable materials by simple weld seams. From a fluidic point of view, the element has a very low pressure drop when flowing around and it creates vortices without a dead water area. Finally, due to its generally hollow interior, the element can be cooled in a variety of ways and with various means.

It is appropriate to choose the ratio of the height h of the connecting edge of the two side surfaces to the channel height H so that the generated vortex pair fills the full channel height or the full height of the channel part assigned to the vortex generator immediately downstream of the vortex generator.

Due to the fact that several vortex generators are arranged side by side without gaps across the width of the channel through which flow flows, the entire channel cross-section is fully loaded by the vortexes shortly behind the vortex generators.

It makes sense if the two side surfaces including the arrow angle α are arranged symmetrically about an axis of symmetry. This creates swirls of equal swirl.

If the two side surfaces enclosing the arrow angle α form an at least approximately sharp connecting edge with one another, which together with the longitudinal edges of the roof surface forms a tip, the flow cross-section is hardly impaired by blocking.

If the sharp connecting edge is the exit-side edge of the vortex generator and it runs perpendicular to the channel wall with which the side surfaces are flush, then the non-formation of a wake area achieved thereby is advantageous. A vertical connecting edge also leads to side surfaces that are also perpendicular to the channel wall, which gives the vortex generator the simplest possible form that is most favorable in terms of production technology.

If the axis of symmetry runs parallel to the channel axis, and the connecting edge of the two side surfaces forms the downstream edge of the vortex generator, while the edge of the roof surface running transversely to the channel through which the flow is flowing is the edge that is first acted upon by the channel flow, then a vortex generator two generated the same opposite vortex. There is a swirl-neutral flow pattern in which the direction of rotation of the two vortices is ascending in the area of the connecting edge.

For certain applications it is expedient if the angle of attack Θ of the roof surface and / or the arrow angle α of the side surfaces are selected such that the vortex generated by the flow bursts in the region of the vortex generator. With the possible variation of the two angles, one has a simple aerodynamic stabilizing means in hand, regardless of the cross-sectional shape of the flowed channel, which can be both wide and low as well as narrow and high, and can be provided with flat or curved channel walls.

Further advantages of the invention, in particular in connection with the arrangement of the vortex generators and the introduction of the secondary flow, result from the subclaims.

Brief description of the drawing

Fig. 1

eine perspektivische Darstellung eines Wirbel-Generators;

Fig. 2

eine Anordnungsvariante des Wirbel-Generators;

Fig. 3a-c

die gruppenweise Anordnung von Wirbel-Generatoren in einem Kanal im Längsschnitt, in einer Draufsicht und in einer Hinteransicht;

Fig. 4a-c

eine Ausführungsvariante einer gruppenweisen Anordnung von Wirbel-Generatoren in gleicher Darstellung wie Fig. 3 mit einer Variante der Sekundarströmungs-führung;

Fig. 5

eine zweite Variante der Sekundarströmungsführung;

Fig. 6

eine dritte Variante der Sekundarströmungsführung;

Fig. 7

die Ringbrennkammer einer Gasturbine mit eingebauten Wirbel-Generatoren;

Fig. 8

einen teilweisen Längsschnitt durch eine Brennkammer nach Linie 8-8 in Fig. 7

Fig. 9

eine zweite Anordnungsvariante für die Wirbel-Generatoren;

Fig. 10

eine dritte Anordnungsvariante für die Wirbel-Generatoren;

Fig. 11

eine vierte Anordnungsvariante für die Wirbel-Generatoren;

Fig. 12

eine fünfte Anordnungsvariante für die Wirbel-Generatoren;

Fig. 13

eine sechste Anordnungsvariante für die Wirbel-Generatoren;

Fig. 14

eine siebte Anordnungsvariante für die Wirbel-Generatoren in einer Draufsicht;

Fig. 15a-c

eine weitere Brennkammer im Längsschnitt, in einer Draufsicht und in einer Hinteransicht.

Fig. 16

eine weitere Ausführungsvariante des Wirbel-Generators;

Fig. 17

eine Anordnungsvariante des Wirbel-Generators nach Fig 16.

Several exemplary embodiments of the invention are shown schematically in the drawing. Show it:

Fig. 1

a perspective view of a vortex generator;

Fig. 2

a variant of the arrangement of the vortex generator;

3a-c

the grouped arrangement of vortex generators in a channel in longitudinal section, in a plan view and in a rear view;

4a-c

an embodiment variant of a group arrangement of vortex generators in the same representation as FIG. 3 with a variant of the secondary flow guide;

Fig. 5

a second variant of the secondary flow control;

Fig. 6

a third variant of the secondary flow control;

Fig. 7

the ring combustion chamber of a gas turbine with built-in vortex generators;

Fig. 8

7 shows a partial longitudinal section through a combustion chamber according to line 8-8 in FIG. 7

Fig. 9

a second arrangement variant for the vortex generators;

Fig. 10

a third arrangement variant for the vortex generators;

Fig. 11

a fourth arrangement variant for the vortex generators;

Fig. 12

a fifth arrangement variant for the vortex generators;

Fig. 13

a sixth arrangement variant for the vortex generators;

Fig. 14

a seventh arrangement variant for the vortex generators in a plan view;

15a-c

another combustion chamber in longitudinal section, in a plan view and in a rear view.

Fig. 16

a further embodiment of the vortex generator;

Fig. 17

a variant of the arrangement of the vortex generator according to FIG. 16.

The direction of flow of the work equipment is indicated by arrows. In the various figures, the same elements are provided with the same reference symbols. Elements not essential to the invention, such as housings, fastenings, cable bushings and the like, have been omitted.

Way of carrying out the invention

Before going into the actual combustion chamber, the vortex generator essential for the mode of operation of the invention is first described.

FIGS. 1, 5 and 6 do not show the actual channel through which a main flow symbolized by a large arrow flows. According to these figures, a vortex generator essentially consists of three free-flowing triangular surfaces. These are a roof surface 10 and two side surfaces 11 and 13. In their longitudinal extent, these surfaces run at certain angles in the direction of flow.

In all of the examples shown, the two side surfaces 11 and 13 are perpendicular to the channel wall 21, it being noted that this is not mandatory. The side walls, which consist of right-angled triangles, are fixed with their long sides on this channel wall 21, preferably gas-tight. They are oriented so that they form a joint on their narrow sides, including an arrow angle α. The joint is designed as a sharp connecting edge 16 and is also perpendicular to the channel wall 21 with which the side surfaces are flush. The two side surfaces 11, 13 including the arrow angle α are symmetrical in shape, size and orientation and are arranged on both sides of an axis of symmetry 17 (FIGS. 3b, 4b). This axis of symmetry 17 is rectified like the channel axis.

The roof surface 10 lies against the same channel wall 21 as the side walls 11, 13 with an edge 15 which runs across the channel and is very pointed.

Its longitudinal edges 12, 14 are flush with the longitudinal edges of the side surfaces protruding into the flow channel. The roof surface extends at an angle of inclination Θ to the channel wall 21. Its longitudinal edges 12, 14 form a tip 18 together with the connecting edge 16.

Of course, the vortex generator can also be provided with a bottom surface with which it is fastened in a suitable manner to the channel wall 21. However, such a floor area is not related to the mode of operation of the element.

In Fig. 1, the connecting edge 16 of the two side surfaces 11, 13 forms the downstream edge of the vortex generator. The edge 15 of the roof surface 10 which runs transversely to the flow through the channel is thus the edge which is first acted upon by the channel flow.

The vortex generator works as follows: When flowing around edges 12 and 14, the main flow is converted into a pair of opposing vortices. Their vortex axes lie in the axis of the main flow. The number of swirls and the location of the vortex breakdown (if the latter is desired at all) are determined by appropriate selection of the angle of attack Θ and the arrow angle α. With increasing angles, the vortex strength or the number of swirls is increased and the location of the vortex bursting moves upstream into the area of the vortex generator itself. Depending on the application, these two angles Θ and α are predetermined by the structural conditions and by the process itself. Only the length L of the element (FIG. 3b) and the height h of the connecting edge 16 (FIG. 3a) then have to be adjusted.

In FIGS. 3a and 4a, in which the channel through which flow is indicated is 20, it can be seen that the vortex generator can have different heights compared to the channel height H. As a rule, the height h of the connecting edge 16 will be coordinated with the channel height H in such a way that the vortex generated immediately downstream of the vortex generator already has such a size that the full channel height H is filled, which results in a uniform velocity distribution in the applied Cross section leads. Another criterion that can influence the ratio h / H to be selected is the pressure drop that occurs when the vortex generator flows around. It goes without saying that the pressure loss coefficient also increases with a larger ratio h / H.

In contrast to FIG. 1, the sharp connecting edge 16 in FIG. 2 is the point which is first acted upon by the channel flow. The element is rotated by 180 °. As can be seen from the illustration, the two opposite vortices have changed their sense of rotation.

In Fig. 3 it is shown how several, here 3 vortex generators are arranged side by side without gaps across the width of the flow channel 20. The channel 20 has a rectangular shape in this case, but this is not essential to the invention.

An embodiment variant with two full and two half vortex generators adjoining it on both sides is shown in FIG. 4. With the same duct height H and the same angle of attack Θ of the roof surface 10 as in FIG. 3, the elements differ in particular by their greater height h. If the angle of attack remains the same, this inevitably leads to a greater length L of the element and consequently - because of the same division - to a smaller arrow angle α. In comparison with FIG. 3, the vortices generated will have a lower swirl strength, but will fill the channel cross section completely within a shorter interval. If in In both cases a vortex burst is intended, for example to stabilize the flow, this will take place later in the vortex generator according to FIG. 4 than in that according to FIG. 3.

The channels shown in FIGS. 3 and 4 represent rectangular combustion chambers. It is pointed out once again that the shape of the channel through which flow passes is not essential for the mode of operation of the invention. Instead of the rectangle shown, the channel could also be a ring segment, i.e. the walls 21a and 21b would be curved. In such a case, the above statement that the side surfaces are perpendicular to the channel wall must of course be relativized. It is important that the connecting edge 16 lying on the line of symmetry 17 is perpendicular to the corresponding wall. In the case of annular walls, the connecting edge 16 would thus be aligned radially, as is shown in FIG. 7.

FIGS. 7 and 8 show in simplified form a combustion chamber with an annular flow through channel 20. On both channel walls 21a and 21b, an equal number of vortex generators are lined up in the circumferential direction in such a way that the connecting edges 16 of two opposite vortex generators lie in the same radial . If the same heights h are assumed for opposite vortex generators, FIG. 7 shows that the vortex generators on the inner channel ring 21b have a smaller arrow α. In the longitudinal section in FIG. 8 it can be seen that this could be compensated for by a larger angle of attack Θ if swirl-like vortices in the inner and outer ring cross-section are desired. In this solution, as indicated in FIG. 7, two vortex pairs are generated, each with smaller vertebrae, which leads to a shorter mixing length. The fuel could be in this version according to the methods of 5 or 6 to be described later are introduced into the main flow.

3 and 4, two flows are mixed with one another with the help of the vortex generators 9. The main flow in the form of combustion air - or fuel gas, depending on the type of combustion chamber - attacks the transverse inlet edges 15 in the direction of the arrow. The secondary flow in the form of a liquid fuel, for example, has a substantially smaller mass flow than the main flow. It is introduced vertically into the main flow in the immediate area of the vortex generators.

3, this injection takes place via individual bores 22a, which are made in the wall 21a. The wall 21a is the wall on which the vortex generators are arranged. The bores 22a are located on the line of symmetry 17 downstream behind the connecting edge 16 of each vortex generator. With this configuration, the fuel is fed into the already existing large-scale vortices.

4 shows an embodiment variant of a combustion chamber in which the secondary flow is also injected via wall bores 22b. These are located downstream of the vortex generators in that wall 21b on which the vortex generators are not arranged, that is to say on the wall opposite the wall 21a. The wall bores 22b are each made centrally between the connecting edges 16 of two adjacent vortex generators, as can be seen in FIG. 4. In this way, the fuel reaches the vortex in the same way as in the embodiment according to FIG. 3, but with the difference that it is no longer mixed into the vortex of a pair of vertebrae produced by the same vortex generator, but in one each Vortex of two neighboring vortex generators. Because the neighboring vortex generators Meanwhile, are arranged without a space and produce vortex pairs with the same direction of rotation, the injections according to FIGS. 3 and 4 have the same effect.

FIGS. 5 and 6 show further possible forms of introducing the secondary flow into the main flow. The secondary flow is introduced here through means not shown through the channel wall 21 into the hollow interior of the vortex generator.

5, the secondary flow is injected into the main flow via a wall bore 22e, the bore being arranged in the region of the tip 18 of the vortex generator.

6, the injection takes place via wall bores 22d, which are located in the side surfaces 11 and 13 on the one hand in the region of the longitudinal edges 12 and 14 and on the other hand in the region of the connecting edge 16.

Finally, FIGS. 9 to 14 show different installation options for the vortex generators.

Like FIG. 7, the partial view in FIG. 9 shows an annular channel 20 in which an equal number of vortex generators 9 are lined up in the circumferential direction both on the outer ring wall 21a and on the inner ring wall 21b. 7, however, the connecting edges 16 of two opposite vortex generators are offset by half a division. This arrangement offers the possibility of increasing the height h of the individual element. Downstream of the vortex generators, the generated vortexes are combined with one another, which on the one hand improves the mixing quality and on the other hand leads to a longer lifespan of the vortex.

In the partial view according to FIG. 10, the ring channel is segmented by means of radially extending ribs 23. A vortex generator 9 is arranged on the ribs 23 in each of the circular ring segments formed in this way. In the case shown, the two vortex generators are designed to fill the entire channel height. This solution simplifies the fuel supply that can be made through the hollow ribs. This means that there is no impairment of the flow by centrally arranged fuel lances.

11, in addition to the lateral vortex generators as in FIG. 10, vortex generators are also attached to the ring walls 21a and 21b. The connecting edges of the side elements run at half the channel height, those of the upper and lower in a radial at half the segment width. In terms of how it works, this is a very good solution. In contrast to the variant according to FIG. 10, the elements here cannot fill the entire channel height. It is therefore not to be overlooked that the cooling that may be required is structurally complex, since cooling air supply from the ring walls is not readily possible for the lateral elements.

In order to remedy this, in contrast to FIG. 11, the vortex generators 9 in FIG. 12 are arranged off-center on the radial ribs 23 and on the ring walls 21a, 21b. One side surface of each vortex generator lies against a corner of the circular ring segment, from where the lateral vortex generators can also be supplied with cooling air from the radially outer ring wall 21a, on the one hand, and from the inner ring wall 21b, on the other hand.

Another embodiment according to FIG. 13 is also in respect of a simple cooling possibility Segment of the circular channel, the vortex generators 9 are arranged directly in the segment corners.

14 shows the possibility of not accommodating the vortex generators in the same plane. Of the vortex generators strung together on a channel wall with their side walls, two adjacent elements are offset from one another in the longitudinal direction of the channel 20. In this variant, a vortex overlap takes place in the circumferential direction. It is a measure that is suitable for optimizing the combination of vertebral pairs. Different geometries can be selected for the vortex generators connected in series. The arrangement in different levels of the channel also has a favorable effect against the ignition of acoustic vibrations.

15a-c show an additional central introduction of the secondary flow in a mixed arrangement of the variants dealt with in FIGS. 6, 11 and 14. The fuel, usually oil, is injected via a central fuel lance 24, the mouth of which is located downstream of the vortex generators 9 in the area of the tip 18 thereof. On the one hand, vortex generators of different geometries are used in the rectangular channel, which of course could just as well be a circular ring segment. Furthermore, the vortex generators that follow one another in the “circumferential direction” are slightly offset from one another. This, for example, to create the required space for the lance. Finally, the secondary flow is partially injected via wall holes in the side surfaces of the vortex generators, as indicated by arrows. The gas supply takes place via gas lines 25 running along the wall. With the configuration shown, such a combustion chamber has become good for dual operation with premix combustion own. With a pressure drop coefficient of 3, thorough mixing is achieved after only 3 duct heights. The mixture is ignited 26 at the point at which the vortex bursts (vortex break down). For additional flame stabilization, a diffuser 27 is arranged in the plane behind the mixing zone at which the ignition takes place. The good temperature distribution downstream of the vortex generators achieved as a result of the mixing elements avoids the risk of reignition, which is possible without the measure for introducing cooling air into the combustion air mentioned at the beginning.

The combustion chamber just described could also be a self-igniting post-combustion chamber downstream of a high-temperature gas turbine. The high energy content of their exhaust gases enables self-ignition. Effective, rapid mixing of the hot gas flow with the injected fuel is a prerequisite for optimizing the combustion process, particularly with regard to minimizing emissions.

If a vortex generator configuration according to FIGS. 15a-c with central injection of the fuel via a lance is used as a basis, the vortex generators are designed in such a way that recirculation zones are largely avoided. As a result, the residence time of the fuel particles in the hot zones is very short, which has a favorable effect on the minimal formation of NO _x . The injected fuel is dragged along by the vortices and mixed with the main flow. It follows the helical course of the vertebrae and is evenly finely distributed in the chamber downstream of the vertebrae. This reduces the risk of impinging jets on the opposite wall and the formation of so-called "hot spots" - in the case of the radial injection of fuel into an undisturbed flow mentioned above.

Since the main mixing process takes place in the vortices and is largely insensitive to the injection pulse of the secondary flow, the fuel injection can be kept flexible and adapted to other boundary conditions. In this way, the same injection pulse can be maintained throughout the load range. Since the mixing is determined by the geometry of the vortex generators and not by the machine load, in the example the gas turbine output, the afterburner configured in this way works optimally even under partial load conditions. The combustion process is optimized by adjusting the ignition delay time of the fuel and mixing time of the vortices, which ensures a minimization of emissions.

Furthermore, the effective mixing results in a good temperature profile over the cross section through which the flow is flowing and also reduces the possibility of the occurrence of thermoacoustic instability. Due to their presence alone, the vortex generators act as a damping measure against thermoacoustic vibrations.

FIGS. 16 and 17 show a top view of an embodiment variant of the vortex generator and a front view of its arrangement in a circular channel. The two side surfaces 11 and 13 enclosing the arrow angle α have a different length. This means that the roof surface 10 rests with an edge 15a running obliquely to the flow through the channel on the same channel wall as the side walls. The vortex generator then naturally has a different angle of attack stell across its width. Such a variant has the effect that vortices with different strengths are generated. For example, this can act on a swirl adhering to the main flow. Or else through the different eddies it becomes original a swirl-free main flow downstream of the vortex generators, as indicated in FIG. 17. Such a configuration works well as an independent, compact burner unit. When using several such units, for example in a gas turbine ring combustor, the swirl imposed on the main flow can be used to improve the cross-ignition behavior of the burner configuration, for example at partial load.

Of course, the invention is not limited to the examples described and shown. With regard to the arrangement of the vortex generators in the network, many combinations are possible without leaving the scope of the invention. The introduction of the secondary flow into the main flow can also be carried out in a variety of ways.

Reference list

9

Vortex generator

10th

Roof area

11

Side surface

12th

Long edge

13

Side surface

14

Long edge

15

transverse edge of 10

16

Connecting edge

17th

Line of symmetry

18th

top

20, a

channel

21, a, b

Canal wall

22, a, b, c, d

Wall hole

23

rib

24th

Fuel lance

25th

Gas pipe

26

Spark ignition

27

Diffuser

Θ

Angle of attack

α

Arrow angle

H

Height of 16

H

Channel height

L

Length of the vortex generator

Claims (23)

Combustion chamber in which a gaseous or liquid fuel is injected as a secondary flow into a gaseous, channeled main flow, the secondary flow having a substantially smaller mass flow than the main flow,
characterized,
that the main flow is conducted via vortex generators (9), of which several are arranged side by side over the width or the circumference of the channel (20) through which flow is flowing, preferably without gaps, and the height (h) of which is at least 50% of the height (H) of the flow through the channel or of the channel part assigned to the vortex generator, and that the secondary flow is introduced into the channel (20) in the immediate area of the vortex generators (9). Combustion chamber according to claim 1, characterized in - That a vortex generator (9) has three free-flowing surfaces that extend in the direction of flow and one of which forms the roof surface (10) and the other two the side surfaces (11, 13), - That the side surfaces (11, 13) are flush with the same channel wall (21) and enclose the arrow angle (α) with each other, - That the roof surface (10) lies with an edge (15) running transversely to the channel (20) through which it flows on the same channel wall (21) as the side walls, - And that the longitudinal edges (12, 14) of the roof surface, which are flush with the projecting into the flow channel longitudinal edges of the side surfaces (11, 13) at an angle (() to the channel wall (21). Combustion chamber according to claim 2, characterized in that the ratio height (h) of the vortex generator to the channel height (H) is selected so that the generated vortex fills the full channel height immediately downstream of the vortex generator (9). Combustion chamber according to claim 2, characterized in that the two side surfaces (11, 13) of the vortex generator (9) including the arrow angle (α) are arranged symmetrically about an axis of symmetry (17). Combustion chamber according to claim 2, characterized in that the two side surfaces (11, 13) of the vortex generator (9) enclosing the arrow angle (α) have a different length, so that the roof surface (10) has a channel (20 ) running edge (15) on the same channel wall (21) as the side walls and across the width of the vortex generator (9) has a different angle of attack (Θ). (Fig. 16, 17) Combustion chamber according to claim 4, characterized in that the two side surfaces (11, 13) including the arrow angle (α) comprise a connecting edge (16) which, together with the longitudinal edges (12, 14) of the roof surface (10), has a tip ( 18), and that the connecting edge preferably runs perpendicular to that channel wall (21) with which the side surfaces (11, 13) are flush. Combustion chamber according to claim 4, characterized in that the connecting edge (16) and / or the longitudinal edges (12, 14) of the roof surface (10) are at least approximately sharp. Combustion chamber according to Claims 4 and 6, characterized in that the axis of symmetry (17) of the vortex generator (9) runs parallel to the channel axis, the connecting edge (16) of the two side surfaces (11, 13) being the downstream edge of the vortex generator ( 9) and the edge (15) of the roof surface (10) running transversely to the channel (20) through which flow is the edge which is first acted upon by the main flow. Combustion chamber according to claim 2, characterized in that the angle of attack (Θ) of the roof surface (10) and / or the arrow angle (α) of the side surfaces (11, 13) are selected so that the vortex generator (9) is still in the area eddies generated by the current burst. Combustion chamber according to claim 2, characterized in that the channel is annular, that the channel wall on which a plurality of vortex generators (9) are lined up in the circumferential direction is the inner or outer ring wall (21a, 21b), and that the secondary flow is injected via wall bores (22a), one of which is located in the symmetry line (17) downstream immediately behind the connecting edge (16) in the same ring wall (21a, 21b) on which the vortex generators (9) are arranged. (Fig. 3) Combustion chamber according to claim 2, characterized in that the channel (20) is annular, that the channel wall, on which a plurality of vortex generators are lined up in the circumferential direction, is the inner and / or outer ring wall (21a, 21b), and that the secondary flow is injected via wall bores (22b) which are arranged downstream of the vortex generators in that ring wall (21b, 21a) on which the vortex generators (9) are not arranged, the wall bores (22b) each being centered between the connecting edges ( 16) two adjacent vortex generators are attached. (Fig. 4) Combustion chamber according to claim 2, characterized in that the channel (20) is ring-shaped and that an equal number of vortex generators (9) are lined up in the circumferential direction both on the outer ring wall (21a) and on the inner ring wall (21b) , wherein the connecting edges (16) of two opposite vortex generators (9) lie on the same radial. (Fig. 7) Combustion chamber according to claim 2, characterized in that the channel (20) is ring-shaped and that an equal number of vortex generators (9) are lined up in the circumferential direction both on the outer ring wall (21a) and on the inner ring wall (21b) , wherein the connecting edges (16) of two opposite vortex generators (9) are offset by half a pitch. (Fig. 9) Combustion chamber according to claim 2, characterized in that the channel (20), at least in the plane in which the vortex generators (9) are located, is an annular channel segmented by means of radial ribs (23), with one vortex in each annular segment. Generator (9) is arranged on the radial ribs (23) and / or on the ring walls (21a, 21b). (Fig. 10, 11) Combustion chamber according to claim 14, characterized in that the vortex generators (9) are arranged centrally on the radial ribs (23) and on the ring walls (21a, 21b). (Fig. 11) Combustion chamber according to claim 14, characterized in that the vortex generators (9) are arranged eccentrically on the radial ribs (23) and on the ring walls (21a, 21b), one side face (11, 13) of each vortex generator ( 9) abuts a corner of the circular ring segment. (Fig. 12) Combustion chamber according to claim 2, characterized in that the channel (20), at least in the plane in which the vortex generators (9) are located, is an annular channel segmented by means of radial ribs (23), with one vortex in each annular segment. Generator (9) is arranged in the corners. (Fig. 13) Combustion chamber according to claim 2, characterized in that each of the vortex generators (9) lined up on a duct wall with their side walls are offset from one another in the longitudinal direction of the duct (20). (Fig. 14) Combustion chamber according to claim 6, characterized in that the secondary flow is injected via wall bores (22c, 22d) which are located in the side walls (11, 13) of the vortex generator (9) in the region of the longitudinal edges (12, 14) of the roof surface and / or the connecting edge (16). (Fig. 6) Combustion chamber according to claim 2, characterized in that the secondary flow is injected via wall bores (22e) which are located in the region of the tip (18) of the vortex generator (9). (Fig. 5) Combustion chamber according to claim 2, characterized in that the secondary flow is injected via fuel lances (24), the orifices of which are located downstream of the vortex generator (9) in the region of the tip (18) thereof. (Fig. 15) Combustion chamber according to Claim 2, characterized in that it is a combustion chamber with premix combustion, a diffuser (27) being arranged downstream of the vortex generators (9) in the plane at which the spark ignition (26) takes place for flame stabilization. (Fig. 15) Use of a combustion chamber according to claim 3 as a self-igniting afterburning chamber.

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