The invention belongs to the field of engine cooling, and particularly relates to an air film cooling hole structure for a turboshaft engine. An air film cooling hole takes a center line of a cylindrical air film hole as a rotation center line, and takes a parabola as a generatrix to rotate 360 degrees so as to obtain the inner surface of the hole, and the air film cooling hole is in a gradually shrinking and expanding shape; and namely, the air film cooling hope in a gradually shrinking and expanding shape comprises an air inlet section with a gradually reduced cross-sectional area and an airoutlet section with a gradually increased cross-sectional area. According to the air film cooling hole, more cooling air flow can be guided into the air film hole through an inlet, the cooling air flow is compressed in the gradual shrinking section of the hole, the flow speed is increased, and the heat exchange effect in the hole is improved; and the hole diameter becomes larger in the gradual expanding section, the pressure and speed are decreased, so that the cooling air flow can be closer to the inner wall of a flame tube, the effect of reducing the wall temperature is achieved, and the comprehensive cooling effect is better than that of the cylindrical air film hole.

Air film cooling hoes structure for turboshaft engine

The invention provides an aero-engine and a silencing system thereof, relates to the technical field of aero-engines, and aims at solving the technical problems that an existing silencer is complex instructure, poor in silencing performance and short in service life. The silencing system comprises a silencing lining pipe with a plurality of silencing holes, a cylinder wall arranged on the outer side of the silencing lining pipe and a filling part arranged between the silencing lining pipe and the cylinder wall. A filler is of a laminated structure and surrounds the periphery of the silencinglining pipe, and a plurality of silencing overflow openings are formed in the right end of the filler. A cooling device is further installed on the outer side of the pipe wall of an engine combustionchamber, and a cooling outlet of the cooling device communicates with the silencing lining pipe. When pulse detonation jet flow of a tail nozzle of the engine passes through the silencing lining pipe,detonation noise generated by the pulse detonation jet flow can be intercepted by the silencing holes in the silencing lining pipe and penetrate through the silencing holes when diffused, and then the detonation noise is weakened and absorbed by the filler in the filling part. The cooling device is cooperated to form a gas-solid phase silencing system, so that the silencing effect is greatly improved. The structure is simple and the service life is long.

Aero-engine and silencing system thereof

The invention discloses specially-shaped mixing holes for adjusting outlet temperature distribution of a combustion chamber, and belongs to the field of combustion of gas turbines. The specially-shaped mixing holes are formed in the inner ring wall surface and the outer ring wall surface of a flame tube of the combustion chamber correspondingly; the specially-shaped mixing holes divide the wall surface of the flame tube into a flame tube front section and a flame tube back section; the specially-shaped mixing holes are evenly distributed in the circumferential direction of the wall surface ofthe flame tube to form mixing jet flows evenly distributed in the circumferential direction, the penetration depth of the mixing jet flows is increased, the contact area of mixing cold air and high-temperature main stream gas is increased, the mixing effect is improved, and the outlet temperature distribution quality of the combustion chamber is improved; the effect of adjusting outlet temperaturedistribution of the combustion chamber is achieved by changing the jet flow penetration depths, the jet flow circumferential expansion angles and the jet flow directions of the mixing holes; and outlet temperature distribution of the combustion chamber is adjusted, so that the temperature quality of an inlet of a turbine is improved, the service life of the turbine is prolonged, and the heat-proof design difficulty of the turbine is reduced.

Specially-shaped mixing holes for adjusting outlet temperature distribution of combustion chamber

The invention provides an oil supply and cooling integrated air suction type pulse detonation engine structure. The oil supply and cooling integrated air suction type pulse detonation engine structureis characterized in that a fuel oil channel is formed in the wall face of the DDT section of the front middle section of a combustion chamber, high temperature of the DDT section of the pulse detonation combustion chamber is fully utilized, fuel oil is preheated and pre-evaporated to a certain extent, and subsequent atomization and combustion process are facilitated; the fuel oil absorbs heat, sothat the wall surface temperature of the front middle section, namely the DDT section, of the combustion chamber is greatly reduced, and compared with traditional air cooling, cooling effects are remarkably improved due to the fact that fuel oil specific heat is far larger than that of air; cooling inlet air, cooling liquid and external auxiliary equipment are omitted, so that sufficient air participates in combustion in the combustion chamber, a working range of an engine is widened, and the thrust-weight ratio is increased; a large number of oil spraying holes are formed in the wall face ofthe front middle section of the engine and the wall face of an engine inlet, a large-area and full-space oil supply mode enables oil and gas in the engine combustion chamber to be evenly distributedand combusted sufficiently, and accordingly the working stability of the pulse detonation engine can be improved; and fuel oil sprayed out of the oil spraying holes in the wall face of the front middle section and incoming flow form a certain angle, and the DDT distance is shortened to a certain extent through disturbance effects, and therefore the axial length of the engine is reduced.

Oil supply and cooling integrated air suction type pulse detonation engine structure

The invention provides a combustion chamber flame tube wall surface structure adopting a double-layer wall impact/Y-shaped multi-inclined-hole-wall composite cooling mode. The composite cooling structure is composed of two layers of walls, the outer side of the composite cooling structure is an impact wall, a plurality of small holes perpendicular to the wall face are distributed, the inner side of the composite cooling structure is a Y-shaped multi-inclined-hole cooling wall, and cooling airflow is sprayed out from the small holes in the impact wall to impact the cold side of the multi-inclined-hole wall to form impact cooling. Cooling air sprayed from the impact holes flows to the peripheral wall at an impact point; when meeting the Y-shaped multi-inclined hole, the cooling air enters the multi-inclined hole and then is sprayed to a multi-inclined hole fuel gas edge to form a gas film to protect the multi-inclined hole fuel gas edge; compared with the traditional multi-inclined hole,the Y-shaped inclined hole has the advantages that the pressure loss is low, the cooling gas consumption is reduced, the gas film distribution is more uniform, the turbulence intensity is low, the cooling effect along the axial direction and the circumferential direction of the flame tube is uniform, and the better performance of the gas film on the inner wall surface of the flame tube is obtained.

Combustion chamber flame tube wall surface structure adopting double-layer wall impact/Y-shaped multi-inclined-hole wall composite cooling mode

The invention discloses a combustor flame tube wall surface structure adopting an impact/gas film double-layer wall composite cooling mode. The composite cooling structure comprises two layers of walls, wherein the outer side is a reverse impact wall, and a plurality of small holes perpendicular to the wall surface are distributed in the outer side; and the inner side is a blade grid channel multi-inclined-hole cooling wall. Cooling gas flow is sprayed out from the small holes in the impact wall, and flows towards the periphery in a wall-attached mode at impact points, so that impact cooling is formed. Then, the cooling gas flow flows into the blade grid wall surface through reverse flow, enters blade grid holes after meeting the blade grid holes, and is sprayed to the gas edges of the blade grid holes to form a gas film, so that the gas edges of the multi-inclined-hole wall are protected. According to the structure, the temperature distribution of the flame tube wall surface can be more uniform, the temperature gradient of the flame tube wall is reduced, and the service life of a flame tube is prolonged.

Combustor flame tube wall surface structure adopting impact/gas film double-layer wall composite cooling mode

The invention provides a novel micro aero-engine combustion chamber, and relates to the technical field of micro aero-engines. Based on the defects that an oil way structure of a traditional micro aero-engine combustion chamber is long in distance, an oil way is prone to deform due to external action and the like, the novel micro aero-engine combustion chamber adopts a spiral evaporation pipe structure, so that the oil way stability is enhanced, and the combustion efficiency is improved; based on the factors that the traditional micro aero-engine combustion chamber is poor in overall fixing effect, and the position of a flame tube is prone to be unstable under the high-temperature effect, the novel micro aero-engine combustion chamber adopts a flame tube fixing device structure so that theflame tube can be effectively fixed, and position deviation of the flame tube caused by vibration in the working process is prevented, and the flame tube can be prevented from being influenced by vibration during working; a double-layer wall surface structure of the flame tube is adopted, and the space between the wall surfaces is filled with porous media so that the effective damping effect canbe achieved; and meanwhile, the flame tube can be cooled to a certain degree, so that the wall surface cooling effect is achieved, and the service life of the wall surfaces of the flame tube is prolonged.

Novel micro aero-engine combustion chamber

The invention provides a combustion chamber with a tail cooling structure. Based on the fact that a large amount of heat generated by a traditional combustion chamber can generate great influences onturbine blades, the structure is mainly characterized in that a guider cooling device is arranged on the tail portion of a flame tube and the wedge-shaped connection manner is adopted for a combustionchamber casing and the wall face of the flame tube, and on one hand, a deflection angle is generated for gas flow coming from the front portion of the flame tube and preparations are made for deflection conducted by a turbine structure, on the rear side, on the gas flow; and on the other hand, a guider a guider is arranged into a hollow structure, cooling holes are formed in the guider, and air flow between the casing and the wall face of the flame tube is introduced into the flame tube to achieve a cooling effect on the gas flow. By means of the cooling structure, the high-temperature gas flow generated in the flame tube can be cooled in time, a good cooling effect is achieved, unceasing loss caused by the high-temperature gas flow to the combustion chamber and a turbine set is reduced,the length of an engine is indirectly decreased, the total weight of the engine is reduced, and the service life of the engine is prolonged.

Cheng Xiangwang

Papers

Oil supply and cooling integrated air suction type pulse detonation engine structure

Combustion chamber flame tube wall surface structure adopting double-layer wall impact/Y-shaped multi-inclined-hole wall composite cooling mode

Combustor flame tube wall surface structure adopting impact/gas film double-layer wall composite cooling mode

Novel micro aero-engine combustion chamber

Combustion chamber with tail cooling structure