Effectiveness of composite optimization of lean and sweep on transonic compressor performance

In order to study the effects of the composite optimization of lean and sweep on the performance of transonic compressor, a transonic stage was conducted with numerical simulation. Comparison and analysis of compressor overall performance and the flow field near the design point in the rotor were performed before and after optimization. The results show that the composition of lean and sweep could improve the flow in the rotor and the compressor performance effectively. It is found that the efficiency was improved over the whole working condition by about 0.9% near the design point and about 0.2% near the stall point. The composition of lean and sweep could redistribute the loads along the blade span and chord, and the flow was improved near the blade tip and hub. The 3D structure of shock wave was changed by making it move backward over the whole blade span, and the form of shock wave near the tip was changed from a strong oblique shock wave at the leading edge to a shock wave system, which consists of a weak oblique shock at the leading edge and a passage shock wave. The composition of lean and sweep also reduced the influence range of double-leakage phenomenon at the blade tip, and it made the interface location of main flow and tip leakage flow move more backward, which reduced the passage blockage near the blade tip and the range of entropy production.