Design And Numerical Investigations Of Axial Aspirated Transonic Compressor Stage

High Thrust-Weight-Ratio has always been one of main goals for modern aeroengine design. And one of the key techniques is the compressor design with high efficiency and high pressure ratio. Aspirated compressor is one of outstanding achievements in the IHPTET Project, which has been investigated by many researchers in MIT. With the help of highly loaded aspirated compressor, it should be possible to design a single stage fan instead of 2 or 3 stages fan used widely during the aero-engine design at present. In order to meet the requirements for highly loaded fan design, the investigations on the transonic aspirated compressor design have been done in this paper. The influences of suction mass flow and suction slot location have been discussed and some design criteria on aspirated compressor profile have been summed up. The blade profile design of both rotor and stator has been finished as well as 3-D stacking, providing a solid basis for the whole aspirated compressor design.First, the aspirated compressor design methodology has been established, with introductions of codes and procedures for using the code. More details of MISES code for aspirated blade profile design have been discussed, including equations, grids, suction and modes, etc.Secondly, based on numerical investigations on the performance of an axial transonic compressor cascade by MISES codes with the different suction slot locations and suction mass-flow, it had been known that for the identical inlet Mach number and flow angle, the optimal suction mass-flow existed corresponding to the given suction slot location. And the optimal suction mass-flow increased as the suction slot located far away from the shock location. The perfect suction slot location should be at the beginning of the transition region where the boundary layer thickness has developed to a local maximum value downstream of the shock location.Finally, some design features of surface isentropic Mach number distribution of transonic aspirated compressor at the leading edge, pre-compression region, pressure recovery region, diverging trailing edge and pressure surface had been discussed and concluded. The blade profile design, the key point of the whole aspirated compressor design, had been completed at the tip, mid-span and hub sections for both rotor and stator. And these element-blades were then stacked by the TAST codes. The blade inverse design matched the S2 through-flow results. And the shape factor over the blade surface was kept under the separation value H_sep= 2.76±0.23. Besides, the diffusion factor of each bladeachieved a value higher than 0.7, which was much higher than the traditional value.