A ribbed wavy trailing-edge strut flame stabilizer

Abstract

The present invention relates to a ribbed wavy trailing-edge strut flame stabilizer, which is composed of a leading edge, a straight section, and a V-shaped wavy trailing edge. Three to five pairs of trapezoidal ribs are arranged on both side surfaces of the straight section. The advantages and beneficial effects of the present invention are as follows: When the afterburner adopts this ribbed wavy trailing-edge strut flame stabilizer, it has good flame stabilization performance, fast flame propagation speed, small flow resistance loss, and high combustion efficiency.

Description

Technical Field

[0001] The invention relates to a wave trailing edge support plate flame stabilizer with ribs, which can be used for an integrated afterburner combustion chamber of a high thrust-to-weight ratio aero-engine and belongs to the field of aerospace technology. Background Art

[0002] The new generation of afterburning turbofan engines pursues a high thrust-to-weight ratio. In terms of the afterburner, it requires simple parts, low cold flow resistance loss, a small proportion of the afterburner section length, and high afterburner combustion efficiency. The afterburner uses a flame stabilizer to stabilize the flame and organize combustion. The performance of the flame stabilizer is a decisive factor affecting the performance of the afterburner. Most of the new generation of afterburner turbofan engines use an integrated afterburner with an integrated design of a rectifier support plate and a flame stabilizer. However, conventional support plate flame stabilizers produce Karman vortex street-type recirculation vortices, which have poor stability and can lead to locally unstable combustion.

[0003] Due to the small proportion of the afterburner section length, the distance from the fuel injection to the trailing edge of the flame stabilizer becomes smaller accordingly. The fuel atomization, evaporation and mixing are not sufficient before ignition, which can easily lead to unstable combustion. When combined with the unstable combustion caused by the recirculation vortex, the combustion instability problem will be amplified, thereby affecting the combustion reaction process. The distance from the trailing edge of the flame stabilizer to the nozzle outlet becomes smaller accordingly, the combustion section becomes shorter, and the flame in the recirculation zone behind the flame stabilizer does not have time to spread horizontally throughout the entire combustion chamber. Part of the oil-gas mixture is not fully burned, and part of the oil-gas mixture does not participate in combustion and is directly discharged, which seriously affects the afterburner combustion efficiency. Summary of the invention

[0004] The object of the present invention is to provide a wavy trailing edge support plate flame stabilizer with ribs, changing the trailing edge of the support plate flame stabilizer into a wavy trailing edge, and arranging ribs on both sides of the support plate flame stabilizer to improve flame stability and flame propagation speed, reduce flow resistance loss, and increase combustion efficiency.

[0005] The present invention is achieved through the following technical solutions.

[0006] A wave trailing edge support plate flame stabilizer with ribs is provided. The V-shaped trailing edge of the support plate flame stabilizer is changed into a V-shaped wave trailing edge, and ribs are arranged on both sides of the support plate flame stabilizer.

[0007] Furthermore, the wavy trailing-edge strut flame stabilizer has an average chord length of 90 - 150 mm, and the span is determined by the specific engine. The wavy trailing-edge strut flame stabilizer mainly consists of a leading edge, a straight section, and a V-shaped wavy trailing edge. On both sides of the straight section, 3 - 5 pairs of ribs are arranged. The leading edge is an elliptical surface, and the major axis dimension of the ellipse is 1.75 - 2.5 times that of the minor axis. The leading edge is tangent and continuous with the straight section. The width of the straight section is 18 - 28 mm, and the width of the V-shaped wavy trailing edge is 24 - 36 mm. The cross-sectional shapes at all positions of the V-shaped wavy trailing edge are the same. The included angle of the rear V-shaped surface is 100° - 150°, and the front V-shaped surface is parallel to the rear V-shaped surface. The side width of the V-shaped wavy trailing edge is 1.5 - 3 mm. The V-shaped wavy trailing edge contains 3 - 5 wavelengths, starting and ending at the wave crest positions. The wavy shape of the V-shaped wavy trailing edge is obtained by rounding the wave crests and wave troughs of the sawtooth wave, with a fillet radius of 15 - 30 mm, and the amplitude of the sawtooth wave is 6 - 15 mm.

[0008] Furthermore, the ribs are 1 - 3 mm thick, trapezoidal on the side, with a leading edge height of 1 - 3 mm and a trailing edge height of 4 - 6 mm. The length of the ribs is 20 - 30 mm. The spacing between the leading edges of adjacent ribs is 7 - 11 mm, and the spacing between the trailing edges of adjacent ribs is 7 - 11 mm. The rib pairs are parallel to the sawtooth edges of the sawtooth wave, and the distance between the ribs and the parallel sawtooth edges at the V-shaped wavy trailing edge is 13 - 18 mm.

[0009] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0010] First, it has good flame stabilization performance. The conventional strut flame stabilizer generates a von Kármán vortex street type recirculation vortex, and the stability of its recirculation vortex is relatively poor. By changing the V-shaped trailing edge of the conventional strut flame stabilizer to a V-shaped wavy trailing edge, a stable K-H type recirculation vortex is generated. Ribs are arranged in parallel in front of the V-shaped wavy trailing edge to form a cavity and strengthen the streamwise vortices induced by the ribs. This configuration and the strengthened streamwise vortices not only facilitate the evaporation and mixing of fuel, but also make the fuel relatively concentrated in the wave troughs, which can expand the stable combustion range. Moreover, the fuel distribution matches the size of the transverse recirculation zone and the position of the streamwise vortices, further facilitating the achievement of stable and efficient combustion.

[0011] Second, it has a fast flame propagation speed. Compared with the conventional strut flame stabilizer, the wave trough recirculation zone of the wavy trailing-edge strut flame stabilizer becomes wider, and the wave crest recirculation zone becomes narrower. The streamwise vortices induced by the ribs are located on both sides of the wave trough recirculation zone, further expanding the range of the wave trough recirculation zone and strengthening the heat and mass convective transport between the recirculation and the mainstream on both sides. Moreover, the fuel is relatively concentrated in the wave troughs, so the combustion reaction is more intense, all of which are conducive to obtaining a faster flame propagation speed.

[0012] Third, the flow resistance loss is small. To achieve the same flame stability performance and flame propagation speed, compared with increasing the blockage width of a conventional strut flame stabilizer, changing the conventional strut flame stabilizer to a wavy trailing-edge strut flame stabilizer and then arranging ribs on both sides of the wavy trailing-edge strut flame stabilizer will cause less flow resistance loss. Moreover, replacing the continuously shedding and breaking Karman vortex street type recirculation vortex with a stable K-H type recirculation vortex is conducive to reducing the flow resistance loss.

[0013] Fourth, the combustion efficiency is high. The trailing section configuration of the wavy trailing-edge strut flame stabilizer with ribs and the strengthened streamwise vortices not only facilitate the evaporation and mixing of fuel, but also cause the fuel to be relatively enriched in the troughs, and expand the trough recirculation zone, so that the fuel distribution matches the size of the transverse recirculation zone and the position of the streamwise vortices. The streamwise vortices can strengthen the heat and mass convective transport between the recirculation and the mainstream on both sides. Therefore, under these combined effects, high combustion efficiency can be obtained within a short distance. Brief Description of the Drawings

[0014] Figure 1 Isometric view of the wavy trailing-edge strut flame stabilizer with ribs in the present invention.

[0015] Figure 2 Side view of the wavy trailing-edge strut flame stabilizer with ribs in the present invention.

[0016] Figure 3 Top view of the wavy trailing-edge strut flame stabilizer with ribs in the present invention.

[0017] Figure 4 Front view of the wavy trailing-edge strut flame stabilizer with ribs in the present invention.

[0018] Figure 5 Rear view of the wavy trailing-edge strut flame stabilizer with ribs in the present invention.

[0019] Figure 6 Longitudinal section V X distribution of the wavy trailing-edge strut flame stabilizer with ribs in the present invention.

[0020] Figure 7 Transverse section V X distribution of the wavy trailing-edge strut flame stabilizer with ribs in the present invention.

[0021] Figure 8 Streamline diagram of the wavy trailing-edge strut flame stabilizer with ribs in the present invention.

[0022] In the attached drawings, 1 is the leading edge; 2 is the straight section; 3 is the V-shaped wavy trailing edge; 4 is the rib; L1 is the mean chord length of the flame stabilizer, L2 is the span length of the flame stabilizer, L3 is the length of the rib, L4 is the distance between the rib and the serrated edge parallel to the trailing edge, L5 is the distance between the leading edges of adjacent ribs, L6 is the distance between the trailing edges of adjacent ribs, L7 is the amplitude of the zigzag wave; α1 is the included angle of the rear V-shaped surface; S1 is the side width of the V-shaped wavy trailing edge, S2 is the thickness of the rib; H1 is the width of the straight section of the flame stabilizer, H2 is the width of the V-shaped wavy trailing edge, H3 is the height of the leading edge of the rib, H4 is the height of the trailing edge of the rib; R is the fillet radius at the peak and valley of the zigzag wave. Detailed implementation mode

[0023] The following will combine the attached Figures 1 to 5 drawings and embodiments to further elaborate on the present invention.

[0024] A ribbed wavy trailing edge strut flame stabilizer changes the V-shaped trailing edge of the strut flame stabilizer to a V-shaped wavy trailing edge 3, and ribs are arranged on both side surfaces of the strut flame stabilizer.

[0025] As a further improvement of the embodiment of the present invention, for the ribbed wavy trailing edge strut flame stabilizer, the mean chord length L1 is 90 - 150 mm, specifically 120 mm in this embodiment, the span length L2 is determined by the specific engine, specifically 180 mm in this embodiment. The ribbed wavy trailing edge strut flame stabilizer mainly consists of a leading edge 1, a straight section 2, and a V-shaped wavy trailing edge 3. 3 - 5 pairs of ribs 4 are arranged on both side surfaces of the straight section 2, specifically 3 pairs in this embodiment; the leading edge 1 is an elliptical surface, the major axis dimension of the ellipse is 1.75 - 2.5 times that of the minor axis, specifically 2 times in this embodiment. The leading edge 1 is tangent and continuous with the straight section 2. The width H1 of the straight section 2 is 18 - 28 mm, specifically 20 mm in this embodiment. The width H2 of the V-shaped wavy trailing edge 3 is 24 - 36 mm, specifically 26 mm in this embodiment. The cross-sectional shapes of each part of the V-shaped wavy trailing edge 3 are the same. The included angle α1 of the rear V-shaped surface is 100° - 150°, specifically 120° in this embodiment. The front V-shaped surface is parallel to the rear V-shaped surface. The side width S1 of the V-shaped wavy trailing edge 3 is 1.5 - 3 mm, specifically 2 mm in this embodiment. The V-shaped wavy trailing edge 3 contains 3 - 5 wavelengths, specifically 3 wavelengths in this embodiment, starting and ending at the peak position. The wavy shape is obtained by rounding the corners at the peak and valley of the zigzag wave. The fillet radius R is 15 - 30 mm, specifically 18 mm in this embodiment, and the amplitude L7 of the zigzag wave is 6 - 15 mm, specifically 12 mm in this embodiment.

[0026] As a further improvement of the embodiment of the present invention, the thickness S2 of the rib is 1 to 3 mm, specifically 2 mm in this embodiment. The side surface is trapezoidal. The height H3 of the leading edge of the rib is 1 to 3 mm, specifically 2 mm in this embodiment. The height H4 of the trailing edge of the rib is 4 to 6 mm, specifically 5 mm in this embodiment. The length L3 of the rib is 20 to 30 mm, specifically 25.5 mm in this embodiment. The distance L5 between the leading edges of adjacent ribs is 7 to 11 mm, specifically 8.7 mm in this embodiment. The distance L6 between the trailing edges of adjacent ribs is 7 to 11 mm, specifically 8.7 mm in this embodiment. The rib pair is parallel to the serrated edge of the sawtooth wave. The distance L4 between the rib 4 and the serrated edge parallel to the trailing edge of the V-shaped wave is 13 to 18 mm, specifically 15.5 mm in this embodiment.

[0027] The above-described embodiments are only the preferred embodiments of the present invention, rather than an exhaustive list of all possible implementations of the present invention. For those of ordinary skill in the art, any obvious modifications made without departing from the principle and spirit of the present invention should be considered to be included within the scope of the claims of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of protection of the claims.

Claims

1. A ribbed wavy trailing-edge strut flame stabilizer, characterized in that, The described wavy trailing-edge strut flame stabilizer has an average chord length of 90 - 150 mm, and the span is determined by the specific engine. The wavy trailing-edge strut flame stabilizer mainly consists of a leading edge (1), a straight section (2), and a V-shaped wavy trailing edge (3). On both sides of the straight section (2), 3 - 5 pairs of ribs (4) are arranged. The leading edge (1) is an elliptical surface, and the major axis dimension of the ellipse is 1.75 - 2.5 times that of the minor axis. The leading edge (1) is tangent and continuous with the straight section (2). The width of the straight section (2) is 18 - 28 mm, and the width of the V-shaped wavy trailing edge (3) is 24 - 36 mm. The cross-sectional shapes at various positions of the V-shaped wavy trailing edge (3) are the same. The included angle of the rear V-shaped surface is 100° - 150°, and the front V-shaped surface is parallel to the rear V-shaped surface. The side width of the V-shaped wavy trailing edge (3) is 1.5 - 3 mm. The V-shaped wavy trailing edge (3) contains 3 - 5 wavelengths, starting and ending at the wave crest positions. The wavy shape of the V-shaped wavy trailing edge (3) is obtained by rounding the wave crests and wave troughs of a sawtooth wave, with a fillet radius of 15 - 30 mm, and the amplitude of the sawtooth wave is 6 - 15 mm. The ribs (4) have a thickness of 1 - 3 mm, and the side surface is trapezoidal. The height of the leading edge of the rib is 1 - 3 mm, and the height of the trailing edge of the rib is 4 - 6 mm. The length of the rib (4) is 20 - 30 mm. The distance between the leading edges of adjacent ribs is 7 - 11 mm, and the distance between the trailing edges of adjacent ribs is 7 - 11 mm. The rib (4) is parallel to the sawtooth edge of the sawtooth wave, and the distance between the rib (4) and the sawtooth edge parallel to the V-shaped wavy trailing edge (3) is 13 - 18 mm.

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