叶尖掉块对跨声速压气机气动性能影响

Effects of Cropped Blade Tip Leading Edge on Aerodynamic Performance of Transonic Compressor

关键词:  叶尖掉块  跨声速压气机  气动性能  激波  泄漏流

Key words:  Cropped blade tip leading edge  Transonic compressor  Aerodynamic performance  Shock wave  Leakage flow

摘要:

为了支撑服役环境下压气机气动性能的评定，通过数值仿真研究了叶尖掉块对跨声速压气机转子气动性能的影响规律和机制。首先利用实验结果对数值仿真方法进行校验，验证了方法的可靠性，进一步对不同形式叶尖掉块下压气机气动性能进行了仿真分析。研究结果表明转子叶尖掉块会使得压气机正常工作状态下压比和效率略有降低，导致压气机近失速点流量明显增大，单一叶尖掉块对应压气机流量稳定裕度下降41.7%；在大流量工况下压气机气动性能与掉块叶片的相对位置并无直接关联，但在近失速点，掉块叶片不相邻时会使得对压气机压比和效率下降更多，但近失速点流量对掉块叶片相对位置的变化并不敏感；转子叶尖掉块会增强叶尖区域泄漏流动，强的泄漏流动与叶片通道激波发生相互作用会引起泄漏涡的破碎，引起较大的流动堵塞和损失，导致压气机气动性能衰减；掉块叶片产生的流动堵塞和吸力面气流的膨胀加速会影响到吸力面侧的掉块叶片，进而限制泄漏流的发展，使得流动堵塞和损失维持在较低水平，但这种影响会随着掉块叶片距离的增大而减弱。

Abstract:

In order to provide support for the evaluation of compressor aerodynamic performances at real working conditions， the effects of cropped blade tip leading edge on the aerodynamic performance of a transonic compressor rotor are investigated numerically. The numerical method is validated using experimental results firstly， and then the compressor with different types of cropped blade tip leading edge is simulated. It is found that cropped blade tip leading edge makes the pressure ratio and efficiency of compressor decrease slightly at normal working conditions， while the mass flow rate based stall margin increases dramatically， stall margin with the single cropped blade tip leading edge decreases by 41.7%. The variation of compressor aerodynamic performance is not directly related to the relative locations of cropped blades at big mass flow rate working conditions， and at near stall working conditions， the compressor pressure ratio as well as efficiency is lower with the cropped blades nonadjacent to each other compared with those adjacent to each other， yet the mass flow rate based stall margin is insensitive to the relative locations of cropped blades. Strength of the tip leakage flow increases by a cropped blade tip leading edge， and the interactions between strong tip leakage flow and blade passage shock wave will induce strong flow blockage as well as loss， thus resulting in the deterioration of compressor aerodynamic performance. Cropped blades will influence the flow of blade passages located on their suction sides and weaken tip leakage flow， through accelerating the mainstream flow as well as reducing the static pressure of blade pressure surface， and then the flow blockage as well as loss of blade passage on the suction side is kept in a low level owing to the weak tip leakage flow， however， this effect is weakened with the increase of the distance of the cropped blade.