摘要:
针对压气机叶片在非设计工况下经常出现的附面层分离状况,通过在转子二叶顶端壁开槽吸气,采用实体槽和源项添加两种数值方法对某双级对转压气机进行吸附式数值模拟,对比分析吸气前后压气机性能特性和内部流场。结果表明:吸除转子叶顶端壁低能流体可以使压气机压比和效率在各流量下得到提高,压比提高约1.25%,效率最大提升近2%;流动分析发现转子二叶顶出口气流角减小,进而减小出口导叶攻角,叶顶区域流动得到显著改善;对比两种数值模拟方法,源项添加数值方法预测压比方面与实体槽接近,而预测效率方面偏大,原因在于实体槽法考虑了槽结构引起的附加损失。
Abstract:
The boundary layer separation frequently happens to compressor blades under the non-design condition. Therefore, through making a slot at the tip region of two blades of a rotor for aspiration, we perform the numerical simulation of the boundary layer suction (BLS) of a double-stage counter-rotational compressor by using the entity slot and adding source terms. Then we make comparative study of the performance characteristics and internal flow field of the compressor before and after aspiration respectively. The study results show that the sucking of low-energy fluid near the rotor tip region can enhance the pressure ratio and efficiency of the compressor under various flow volumes,with its total pressure ratio increasing by about 1.25% and the efficiency increasing by nearly 2%. The flow analysis show that the outlet flow angle at the tip region of the two blades of the rotor is reduced, thus reducing the OGV attack angle and improving the flow of the blade tip region significantly. The pressure ratio prediction results with the source term addition method are close to those with the entity slot method but have a greater prediction efficiency. The reason is that the entity slot method considers the additional loss caused by slot structure.
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