Study On Additive Design Manufacturing And Peformance

Micro gas turbine is widely used in aerospace,ground transportation,marine application and distributed power generation because of its high power density,simple structure and low maintenance cost.As the core component of micro gas turbine,combustor is usually limited by its limited space size and poor fuel atomization quality,while additive manufacturing technology breaks the limitations of traditional processing technology and can realize the individualized design and processing of combustor quickly,especially for the parts with complex internal structure,shows its unique advantages.In this paper,the 50 kg thrust stage turbojet engine(NK-50)reverse flow combustor is taken as the research object,numerical simulation and comprehensive performance test of full annular combustor are used as the performance research methods,aiming to improve the comprehensive performance of the combustor through structural innovation and improved design.The main tasks are as follows:According to the overall aerodynamic design parameters of the NK-50 turbojet engine,the basic contour size and air flow distribution of the combustor are calculated based on the empirical / semi empirical formula,and the overall structure of the combustor is designed by using the 3D modeling software Solidworks,considering the limitations of the metal additive manufacturing structural support technology,the flame tube is divided into two parts: the integrated design part of exhaust elbow and turbine guide vane as well as the evaporation tube and the flame tube,which greatly reduces the number of parts,the assembly difficulty and the processing costs of the flame tube.In the preliminary design stage of the overall structure of the combustor,considering the "freedom" of the additive manufacturing process,the concept of the combustor design of the air intake mode at the head of the "V" type evaporation tube and the air intake mode at the middle of the "L" type evaporation tube are proposed,and numerical simulation was carried out on the two version of the combustor,respectively from the combustor flow field,temperature field,the combustor exit temperature distribution,combustion efficiency of two version of combustor performance comparison and analysis,provide a reference basis for combustion chamber structure improved design.On the basis of the L-shaped evaporation pipe design of the air intake mode at the middle of the air intake,this paper puts suggests the outlet of the flat mouth evaporation pipe,and improves the design of the radius of the dome at the head of the flame tube and the arrangement of the air inlet.It is concluded that the flat mouth evaporation pipe is conducive to the formation of a circumferentially continuous return area at the head of the flame tube,and the increase of the dome radius at the head can effectively increase the size of the return area,which is conducive to the stability of the flame.The design scheme of distributing the air flow in the inner and outer rings and arranging the air inlet reasonably is beneficial to build the uniform distribution of oil and gas,to the zoned combustion and to improve the performance of the combustor...