Corrugated heat shield in aero-engine combustion chamber

Abstract

The invention discloses a corrugated heat shield in an aero-engine combustion chamber, which comprises a corrugated heat shield and an air film hole row arranged on the corrugated heat shield, the corrugated heat shield is of a cylinder structure, and a longitudinal corrugated cylinder is coaxially arranged in a combustion chamber / spray pipe cylinder. An annular gradually-shrinking gap between the outer surface of the corrugated barrel and the inner surface of the combustion chamber / spray pipe barrel forms a cooling channel. The corrugated heat insulation screen is of a periodic longitudinal asymmetric corrugated structure, each corrugation comprises a crest area and a trough area, the crest area is of an arc structure, the trough area is of a straight structure, 4-6 rows of staggered exhaust film holes are formed in the corrugated heat insulation screen from the crest position in the axial direction at equal intervals, and the air film holes are distributed in the corrugated heat insulation screen in a non-uniform mode. The cooling device can be used for aero-engine combustion chambers, afterburners or spray pipes, can meet the cooling design requirement of the heat screen, and improves the cooling efficiency.

Description

Technical Field

[0001] The invention relates to a combustion chamber in an aeroengine, and in particular to a longitudinal corrugated heat shield arranged in the combustion chamber, belonging to the technical field of cooling the combustion chamber of an aeroengine. The longitudinal corrugated heat shield of the invention can be used in a combustion chamber, an afterburner and a tail nozzle. Background Art

[0002] At present, the afterburner of an aircraft engine is usually cooled by a cylindrical heat shield with air film cooling holes. The air film cooling technology of the porous longitudinal corrugated heat shield on the surface of the cylinder is widely used in the afterburner of military aircraft engines, which plays a role in suppressing oscillating combustion and preventing high-temperature ablation of the combustion chamber cylinder. With the increase of engine thrust, the gas temperature of the afterburner continues to rise, and the air flow used for cooling is reduced. It is necessary to develop a more advanced heat shield cooling structure, strive to achieve better cooling effect with as little cold air as possible, so as to improve the cooling efficiency of the engine combustion chamber.

[0003] See also Figure 1 , 2 , most of the early cylindrical heat insulation screens adopted a flat plate structure, which had uniform cooling but poor adaptability to thermal deformation. The periodic corrugated structure of the periodic sinusoidally symmetrical longitudinal corrugated heat insulation screen solves the problem of high-temperature thermal deformation of the heat insulation screen, and the cold air can stably stay in the trough of the longitudinal corrugated plate, which plays a good protective role for the heat insulation screen. However, at the same time, due to the expansion of the cross-section of the heat flow channel at the trough, an adverse pressure gradient is generated, and a complex vortex structure is formed at the trough. The mixing of hot and cold flows reduces the protective effect of the cooling air film on the downstream wave crest. Existing studies have shown that increasing the proportion of the windward side length of the cold flow in a single cycle is conducive to enhancing the protective effect of the trough cold air on the downstream wave crest and improving the average comprehensive cooling effect of the corrugated heat insulation screen.

[0004] In addition to the corrugated structure, different arrangements of air film holes will also affect the cooling effect of the longitudinal corrugated heat shield. Figure 1 , 2 ) The corrugated plate is uniformly and densely opened with holes, but the structural characteristics of the corrugation will lead to uneven air film jet. By opening air film holes with different spacings on the windward and leeward sides of the corrugation, the cooling airflow can be more reasonably distributed. The appropriate hole arrangement can further improve the cooling efficiency of the corrugated heat insulation screen. Existing studies have shown that under the same conditions, increasing the number of air film holes on the windward side of the heat insulation screen can effectively improve the cooling efficiency of the heat insulation screen.

[0005] At present, most of the research focuses on sinusoidal symmetrical longitudinal corrugated heat shields, and less consideration is given to the influence of corrugated structure changes and non-uniform hole layout on the cooling effect of heat shields. Existing research on non-uniform hole layout only focuses on sinusoidal symmetrical longitudinal corrugated heat shield structures, and research on corrugated structures is also limited to changing the ratio of the length of the windward side to the leeward side of the corrugation within a half-cycle. There is room for optimization of the corrugated structure and the overall air film hole layout. Summary of the invention

[0006] In order to overcome the shortcomings of the prior art, the present invention proposes a corrugated heat insulation screen in the combustion chamber of an aircraft engine based on the corrugated structure and the arrangement of air film holes, optimizes the design of the corrugated structure and the arrangement of air film holes on the heat insulation screen, and improves the cooling efficiency and cold air utilization efficiency of the corrugated heat insulation screen in the combustion chamber / nozzle cooling channel.

[0007] To achieve the above-mentioned purpose, the technical scheme adopted by the present invention is as follows: a corrugated heat insulation screen in the combustion chamber of an aircraft engine, comprising a corrugated heat insulation screen and an air film hole row arranged on the corrugated heat insulation screen, the corrugated heat insulation screen is a cylindrical structure, and continuous periodic corrugations are arranged on the cylinder wall along the axial direction, each periodic corrugation is the same and includes two parts, a crest area and a trough area, and the air film hole row is evenly distributed on the crest and trough of each periodic corrugation along the circumference of the cylinder, the row spacing of the air film hole row along the axial direction is equal, the positions and numbers of the air film holes in the odd-numbered rows are the same, the positions and numbers of the air film holes in the even-numbered rows are the same, but the air film holes in the even-numbered rows are circumferentially offset from the air film holes in the odd-numbered rows, and the apertures of all the air film holes are the same, the corrugated heat insulation screen is coaxially installed inside the combustion chamber / nozzle barrel, and the annular reduction gap between the outer surface of the corrugated heat insulation screen barrel and the inner surface of the combustion chamber / nozzle barrel forms a cooling channel, which is characterized in that the crest area is an arc structure and the trough area is a straight structure.

[0008] Furthermore, the radius of curvature R of the arc in the crest area is 10-100 mm, and the crest areas of each continuous corrugation period of the corrugated heat insulation screen from the axial direction of the first end are all the same concave wave arcs, and the trough areas are all the same straight structures.

[0009] Furthermore, the axial length of each period of the corrugated heat insulation screen is L, and 4-6 exhaust film holes are arranged on it, and the first exhaust film hole is arranged at the crest. The axial lengths of the crest area and the trough area of ​​the corrugated heat insulation screen are L / 2, and the value of L is 30-120mm; the thickness of the corrugated heat insulation screen is t f , with a value of 0.5-1.5mm; in each cycle of the corrugated heat insulation screen, the flow spacing of the air film hole row is s f , the value is 0.05L-0.2L; the spanwise spacing of the air film hole row is p f, with a value of 0.03L-0.1L; the circumferential offset distance between two adjacent rows of exhaust film holes is b f , the value is 1 / 2p f .

[0010] Furthermore, the opening direction of the air film holes on the corrugated heat insulation screen is perpendicular to the corrugated heat insulation screen where the air film holes are located, and the air film hole diameter d f The value is 0.5-2mm.

[0011] Preferably, the corrugated heat insulation screen has four rows of staggered air film holes arranged at equal intervals along the axial direction from the wave crest, and the four air film holes are all arranged in the wave crest area. The thickness of the heat insulation screen plate is t f is 1.2 mm, the period length L is 60 mm, the radius of curvature R of the wave crest area is 37.4 mm, the axial length is L / 2, the axial length of the wave trough area is L / 2, and the flow spacing s of the air film holes f is 0.08L, i.e. 4.8mm, and the spanwise spacing p f is 0.04L, i.e. 2.4mm. The air film hole spacing ratio is defined as the flow direction spacing s of the air film holes. f Spacing p from the air film hole f The ratio is 2; the circumferential offset distance between two adjacent exhaust film holes is b f =1 / 2p f ; Diameter of air film hole d f The corrugated heat insulation screen has a diameter of 1 mm and a hole direction perpendicular to the location of the air film holes. The air film hole opening rate, that is, the ratio of the total area of ​​all air film holes to the total surface area of ​​the heat insulation screen including the total area of ​​the air film holes, is 2.18%.

[0012] Preferably, the corrugated heat insulation screen has 5 rows of staggered exhaust film holes arranged equidistantly along the axial direction from the wave crest, wherein the first 3 exhaust film holes are arranged in the wave crest area, and the last 2 exhaust film holes are arranged in the wave trough area. The thickness of the corrugated heat insulation screen plate is t f is 1.2 mm, the period length L is 60 mm, the radius of curvature R of the wave crest area is 37.4 mm, the axial length is L / 2, the axial length of the wave trough area is L / 2, and the flow spacing s of the air film holes f is 0.1L, i.e. 6mm, and the span spacing p f is 0.05L, i.e. 3mm. The air film hole spacing ratio is defined as the flow direction spacing s of the air film holes. f Spacing p from the air film hole f The ratio = 2; the circumferential offset distance between two adjacent exhaust film holes is b f =1 / 2p f ; Diameter of air film hole d f The corrugated heat insulation screen has a diameter of 1 mm and a hole direction perpendicular to the location of the air film holes. The air film hole opening rate, that is, the ratio of the total area of ​​all air film holes to the total surface area of ​​the heat insulation screen including the total area of ​​the air film holes, is 2.18%.

[0013] Advantages and significant effects of the present invention: The present invention optimizes the overall arrangement of the corrugated structure and the air film holes, transforms the traditional corrugated structure in the trough area into a straight structure, relatively increases the length proportion of the windward side of the corrugated plate in a single cycle, and weakens the adverse pressure gradient caused by the expansion of the cross-section of the heat flow channel in the trough area, thereby enabling the cold air to stably reside in the trough area, while enhancing the protective effect of the cold air in the trough on the downstream wave crest, thereby improving the cooling efficiency of the corrugated heat insulation screen. At the same time, by opening air film holes at the wave crest on the windward side of the corrugation, and utilizing the Coanda effect near the wave crest, the air film is attached to the corrugated heat insulation screen board, which has the effect of isolating the mainstream heat exchange, making the distribution of the cooling gas more reasonable, and improving the cold air utilization efficiency of the corrugated heat insulation screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 , 2 It is a schematic diagram of the cross-sectional structure of a prior art sinusoidal wave corrugated heat insulation screen;

[0015] Figure 3 This is a three-dimensional diagram of the overall structure of the corrugated heat insulation screen of the present invention;

[0016] Figure 4 yes Figure 3 A vertical half-section diagram of

[0017] Figure 5 It is a cross-sectional diagram of the crest area and trough area on a periodic corrugated heat shield;

[0018] Figure 6 yes Figure 5 A top view of

[0019] Figure 7 yes Figure 6 Schematic diagram of the flattened projection;

[0020] Figure 8 This is Embodiment 1 of the present invention;

[0021] Fig. 9 This is the second embodiment of the present invention;

[0022] FIG10 is a temperature distribution cloud diagram of the hot side of a single-cycle corrugated heat insulation screen at the same position of the corrugated heat insulation screen, that is, at the same x-coordinate range along the axial direction, where x is the axial distance of the corrugated heat insulation screen, and z is the span distance of the corrugated heat insulation screen;

[0023] Fig.10a is a color-coded legend for the hot side temperature of the corrugated heat shield;

[0024] Fig.10b Corresponding to the existing technology Figure 1 Temperature distribution cloud diagram of the hot side of the corrugated heat shield;

[0025] Fig.10c Corresponding to the existing technology Figure 2 Temperature distribution cloud diagram of the hot side of the corrugated heat shield;

[0026] Fig.10d Corresponding to the present invention Figure 8 Temperature distribution cloud diagram of the hot side of the corrugated heat insulation screen of Example 1;

[0027] Fig.10e Corresponding to the present invention Fig. 9 Temperature distribution cloud diagram of the hot side of the corrugated heat insulation screen of Example 2;

[0028] Fig.11 It is a curve diagram of the span-wise average film cooling efficiency of the corrugated heat shield in the combustion chamber. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is described in more detail below with reference to the accompanying drawings and embodiments.

[0030] See also Figure 3 , a cylindrical corrugated heat insulation screen 1 of equal diameter is provided with continuous periodic corrugations along the axial direction, each periodic corrugation includes a crest area 6 and a flat trough area 7, and an air film hole row 2 is evenly arranged on the crest area 6 and the trough area 7 of each period along the circumference of the cylinder, and 3 is an air film hole. The crest area 6 is an arc structure, and the trough area 7 is a straight structure. Starting from the axial direction of the first end, the crest area 6 of each continuous corrugation period is the same concave arc, 4 is a concave crest, and the trough area 7 is the same straight structure 5.

[0031] See also Figure 4 The corrugated heat insulation screen 1 with continuous periodic corrugations is coaxially installed inside the combustion chamber / nozzle barrel. The annular reduction gap between the outer surface of the corrugated heat insulation screen barrel and the inner surface of the combustion chamber / nozzle barrel 8 forms a cooling channel A for low-temperature cold air to flow through, and high-temperature combustion gas B flows inside the corrugated heat insulation screen barrel.

[0032] See also Figure 5 The wave crest area on a period of corrugated heat insulation screen 1 is a concave wave, on which there are 5 rows of air film holes 2 arranged staggered between rows, and 3 air film holes are arranged in the concave wave area. The air film holes in the first row are arranged at the wave crest 4 of the concave wave. The trough area is a straight structure 5, on which there are 2 air film holes. The number of the 5 rows of circumferential cylindrical air film holes 3 located on the entire circumference of the cylinder is the same, and the aperture is also the same.

[0033] See also Figure 6 The axial length of each cycle of the heat shield is L, which is 30-120 mm; the axial lengths of the peak area 6 and the trough area 7 are L / 2 respectively, and the thickness of the heat shield is t f , the value is 0.5-1.5mm; Hf is the ripple height, R is the radius of curvature of the concave wave arc in the crest area, and the value is 10-100mm.

[0034] See also Figure 7 , the flow spacing of the air film hole row (air film hole row spacing) is s f , the value is 3-12mm; the spanwise spacing of the air film hole row is p f , the value is 2-6mm; the circumferential offset (dislocation) distance between two adjacent rows of exhaust film holes is b f , the value is 1 / 2p f The opening direction of the air film hole is perpendicular to the corrugated heat insulation screen where the air film hole is located. The air film hole diameter d f The value is 0.5-2mm.

[0035] Figure 8 This is the first embodiment of the present invention. As shown in the figure, the corrugated heat insulation screen is arranged with 4 rows of staggered air film holes at equal intervals along the axial direction from the wave crest. The 4 air film holes are all arranged in the wave crest area, showing a non-uniform distribution. In this embodiment, the thickness of the heat insulation screen plate is t f is 1.2 mm, the period length L is 60 mm, the radius of curvature R of the wave crest region is 37.4 mm, the axial length is L / 2, and the axial length of the wave trough region is L / 2. In this embodiment, the flow spacing s of the air film holes is f is 0.08L, i.e. 4.8mm, and the spanwise spacing p f is 0.04L, i.e. 2.4mm, and the air film hole spacing ratio is the flow direction spacing s of the air film holes. f Spacing p from the air film hole f The ratio = 2 remains unchanged; the circumferential offset distance between two adjacent exhaust film holes is b f 1 / 2p f ; Diameter of air film hole d f The corrugated heat insulation screen has a diameter of 1 mm and a hole direction perpendicular to the location of the air film holes. The air film hole opening rate, that is, the ratio of the total area of ​​all air film holes to the total surface area of ​​the heat insulation screen including the total area of ​​the air film holes, is 2.18%.

[0036] Fig. 9 This is the second embodiment of the present invention. As shown in the figure, the corrugated heat insulation screen is arranged with 5 rows of staggered exhaust film holes at equal intervals along the axial direction from the wave crest, wherein the first 3 exhaust film holes are arranged in the wave crest area, and the last 2 exhaust film holes are arranged in the wave trough area. The air film holes are arranged on the corrugated heat insulation screen in a non-uniform distribution. In this embodiment, the thickness of the corrugated heat insulation screen plate is t f is 1.2 mm, the period length L is 60 mm, the radius of curvature R of the wave crest region is 37.4 mm, the axial length is L / 2, and the axial length of the wave trough region is L / 2. In this embodiment, the flow spacing s of the air film holes is f 0.1L, i.e. 6mm, spanwise spacing p fis 0.05L, i.e. 3mm, and the air film hole spacing ratio is the flow direction spacing s of the air film holes. f Spacing p from the air film hole f The ratio = 2 remains unchanged; the circumferential offset distance between two adjacent exhaust film holes is b f 1 / 2p f ; Diameter of air film hole d f The corrugated heat insulation screen has a diameter of 1 mm and a hole direction perpendicular to the location of the air film holes. The air film hole opening rate, that is, the ratio of the total area of ​​all air film holes to the total surface area of ​​the heat insulation screen including the total area of ​​the air film holes, is 2.18%.

[0037] Table 1 shows the structural features and numerical calculation methods of the embodiment of the present invention and the traditional model. The structural feature of the traditional model is a sinusoidal central symmetrical corrugated plate, and the rows of air film holes on the corrugated plate are evenly distributed along the axial direction. Figure 1 The structural feature of the conventional model 1 is a sinusoidal central symmetrical corrugated plate, but the distribution of the air film hole rows on the corrugated plate adopts the non-uniform distribution of the air film hole rows in the present invention. Figure 2 , the structural features of the first and second embodiments are the novel asymmetric corrugated plate configuration of the present invention and the non-uniformly distributed air film hole rows arranged thereon. The four corrugated heat shield models are all simulated and calculated using the same numerical calculation method. 1 / 72 of the heat shield circumference is taken as the calculation domain. The calculation domain is set periodically. Fluentmeshing is used to divide the calculation domain into unstructured grids. The turbulence model uses the Realizable k-ε model to solve the steady-state compressible Reynolds time-averaged Navier-Stokes equations. The implicit separation method is used to solve the pressure-velocity coupling. The SIMPLE algorithm is used. The convection term is discretized using the second-order upwind method. The near-wall area uses enhanced wall treatment. The energy equation has no heat source, and the viscous dissipation term is ignored. The residual convergence accuracy is less than 1×10 -4 , and the monitored hot side wall temperature no longer changes. The cooling effect of each model is evaluated by comprehensive cooling efficiency, which is defined as the difference between the high temperature gas temperature and the hot side wall temperature of the heat shield divided by the difference between the high temperature gas temperature and the cold air temperature. The average comprehensive cooling efficiency of the four corrugated heat shield models is shown in Table 1. It can be seen that the traditional model has the lowest average comprehensive cooling efficiency and the worst cooling effect. The traditional model is ranked first. The comprehensive cooling efficiency of the two embodiments of the present invention is better than the two traditional models, among which the average comprehensive cooling efficiency of embodiment 2 is the largest and the cooling effect is the best.

[0038] Table 1 Numerical calculation method of the embodiment of the present invention and traditional model

[0039]

[0040]

[0041] FIG. 10 is a cloud diagram of the temperature distribution of the single-cycle hot side of the corrugated heat insulation screen of the embodiment of the present invention and the traditional model.

[0042] in, Fig.10a This is the temperature color code for the hot side of the corrugated heat shield. Fig.10b This is the temperature distribution cloud diagram of the hot side of the corrugated heat shield of the traditional model. Fig.10c This is the thermal image of the corrugated heat shield of the traditional model 1. Fig.10d This is a temperature distribution cloud diagram of the hot side of the corrugated heat insulation screen of Example 1 of the present invention. Fig.10e This is a cloud diagram of the temperature distribution on the hot side of the corrugated heat insulation screen of Example 2 of the present invention. At the same position of the corrugated heat insulation screen, that is, in the same x-coordinate range along the axial direction, as shown in the figure, the hot side temperature of the traditional model is the highest among the four corrugated heat insulation screen models, and a high temperature area close to 600K appears at the axial distance x=610mm. At the same time, the temperature distribution is also the most uneven, and the maximum temperature difference of the heat insulation screen in a single cycle is nearly 80K, indicating that the cooling effect of the traditional model is the worst; the overall temperature of the traditional model 1 is lower than that of the traditional model, and the temperature difference of the heat insulation screen in a single cycle is also reduced, and the cooling effect is improved; compared with the traditional model 1, the maximum temperature of the hot side of the heat insulation screen of Example 1 of the present invention is further reduced, and the cooling uniformity is further improved; among the four heat insulation screens, Example 2 of the present invention has the lowest hot side temperature, the most uniform temperature distribution, and the best cooling effect.

[0043] See also Fig.11 ,yes Figure 1 (Traditional Model), Figure 2 (Traditional Model 1), Figure 8 (Example 1) and Fig. 9 (Example 2) Curves of the average air film cooling efficiency of four types of corrugated heat insulation screens in the direction of the corrugated heat insulation screen along the combustion chamber. The corrugated heat insulation screen has a total of 23 cycles along the axial direction. As shown in the figure, the cooling efficiency of the two traditional models is the lowest, the fluctuation amplitude along the process is the largest, and the uniformity of the cooling effect distribution is the worst. The cooling efficiency of traditional model one has improved, but the fluctuation amplitude is still large, and the cooling uniformity is poor. The cooling efficiency of Example 1 and Example 2 of the present invention is relatively high overall, and the cooling uniformity of Example 2 is the best, and the cooling efficiency downstream along the process is the highest.

Claims

1. A corrugated heat shield in an aircraft engine combustion chamber, comprising a corrugated heat shield and an air film hole row arranged on the corrugated heat shield, wherein the corrugated heat shield is a cylindrical structure, and continuous periodic corrugations are arranged on the cylinder wall along the axial direction, each periodic corrugation is the same and includes a wave crest area and a wave trough area, and the air film hole row is evenly distributed on the wave crest and wave trough of each periodic corrugation along the circumference of the cylinder, and the row spacing of the air film hole row along the axial direction is equal, the positions and numbers of the air film holes in the odd-numbered rows are the same, the positions and numbers of the air film holes in the even-numbered rows are the same, but the air film holes in the even-numbered rows are circumferentially offset from the air film holes in the odd-numbered rows, and the apertures of all the air film holes are the same, and the corrugated heat shield is coaxially installed inside the combustion chamber / nozzle barrel, and the annular reduction gap between the outer surface of the corrugated heat shield barrel and the inner surface of the combustion chamber / nozzle barrel forms a cooling channel, characterized in that: The crest area is an arc structure, and the trough area is a straight structure.

2. The corrugated heat shield in the combustion chamber of an aircraft engine according to claim 1, characterized in that: The corrugated heat insulation screen has a same concave wave arc in the crest area of ​​each continuous corrugation period from the axial direction of the head end, and a same straight structure in the trough area.

3. The corrugated heat shield in the combustion chamber of an aircraft engine according to claim 1 or 2, characterized in that: The curvature radius R of the circular arc in the peak area is 10-100 mm.

4. The corrugated heat shield in the combustion chamber of an aircraft engine according to claim 3, characterized in that: The axial length of each period of the corrugated heat insulation screen is L, and 4-6 exhaust film holes are arranged on it, and the first exhaust film hole is arranged at the wave crest.

5. The corrugated heat shield in the combustion chamber of an aircraft engine according to claim 4, characterized in that: The axial lengths of the crest region and the trough region of the corrugated heat insulation screen are L / 2 respectively, and the value of L is 30-120 mm.

6. The corrugated heat shield in the combustion chamber of an aircraft engine according to claim 1, 2, 4 or 5, characterized in that: The thickness of the corrugated heat shield is t f , the value is 0.5-1.5mm.

7. The corrugated heat shield in the combustion chamber of an aircraft engine according to claim 6, characterized in that: In each cycle of the corrugated heat insulation screen, the flow spacing of the air film hole rows is s f , the value is 0.05L-0.2L; the spanwise spacing of the air film hole row is p f , with a value of 0.03L-0.1L; the circumferential offset distance between two adjacent rows of exhaust film holes is b f , the value is 1 / 2p f .

8. The corrugated heat shield in the combustion chamber of an aircraft engine according to claim 7, characterized in that: The opening direction of the air film hole on the corrugated heat insulation screen is perpendicular to the corrugated heat insulation screen where the air film hole is located, and the air film hole diameter d f The value is 0.5-2mm.

9. The corrugated heat shield in the combustion chamber of an aircraft engine according to claim 4, characterized in that: The corrugated heat insulation screen is provided with 4 rows of staggered air film holes at equal intervals along the axial direction from the wave crest, and the 4 air film holes are all arranged in the wave crest area. The thickness of the heat insulation screen plate is t f is 1.2 mm, the period length L is 60 mm, the radius of curvature R of the wave crest area is 37.4 mm, the axial length is L / 2, the axial length of the wave trough area is L / 2, and the flow spacing s of the air film holes f is 0.08L, i.e. 4.8mm, and the spanwise spacing p f is 0.04L, i.e. 2.4mm. The air film hole spacing ratio is defined as the flow direction spacing s of the air film holes. f Spacing p from the air film hole f The ratio is 2; the circumferential offset distance between two adjacent exhaust film holes is b f =1 / 2p f ; Diameter of air film hole d f The corrugated heat insulation screen has a diameter of 1 mm and a hole direction perpendicular to the location of the air film holes. The air film hole opening rate, that is, the ratio of the total area of ​​all air film holes to the total surface area of ​​the heat insulation screen including the total area of ​​the air film holes, is 2.18%.

10. The corrugated heat shield in the combustion chamber of an aircraft engine according to claim 4, characterized in that: The corrugated heat insulation screen is provided with 5 rows of staggered exhaust film holes at equal intervals along the axial direction from the wave crest, wherein the first 3 exhaust film holes are arranged in the wave crest area, and the last 2 exhaust film holes are arranged in the wave trough area. The thickness of the corrugated heat insulation screen plate is t f is 1.2 mm, the period length L is 60 mm, the radius of curvature R of the wave crest area is 37.4 mm, the axial length is L / 2, the axial length of the wave trough area is L / 2, and the flow spacing s of the air film holes f is 0.1L, i.e. 6mm, and the span spacing p f is 0.05L, i.e. 3mm. The air film hole spacing ratio is defined as the flow direction spacing s of the air film holes. f Spacing p from the air film hole f The ratio = 2; the circumferential offset distance between two adjacent exhaust film holes is b f =1 / 2p f ; Diameter of air film hole d f The corrugated heat insulation screen has a diameter of 1 mm and a hole direction perpendicular to the location of the air film holes. The air film hole opening rate, that is, the ratio of the total area of ​​all air film holes to the total surface area of ​​the heat insulation screen including the total area of ​​the air film holes, is 2.18%.

Images