蜗壳对斜流压气机气动性能影响研究

Study on the Influence of Volute on the Aerodynamic Performance of a Diagonal Flow Compressor

为了探究蜗壳对某斜流压气机气动性能以及内部流动的影响规律,本文建立了三种数值模拟计算域方案,对不加蜗壳和加装蜗壳压气机进行稳态流动仿真。结果表明:加装蜗壳后,压气机压比增大,其主要原因是轴流段扩压器内总压损失减小;蜗壳内不均匀的压力分布使得压气机出口形成周向压力畸变,部分扩压器叶片前缘攻角增大,流向逆压力梯度增大,吸力面出现高熵区,气流更容易分离,从而使得失速发生在更大流量工况下,喘振边界向大流量方向移动;蜗壳对压气机堵塞边界没有产生明显影响。

In order to explore the influence of the volute on the aerodynamic performance and internal flow of a diagonal flow compressor, three numerical simulation calculation domain schemes are established in this paper, and the steady-state flow simulation of the compressor without volute and with volute is carried out. The results show that the compressor pressure ratio increases after the volute is installed, and the main reason is that the total pressure loss in the diffuser in the axial flow section decreases;the uneven pressure distribution in the volute causes the circumferential pressure distortion at the compressor outlet, the leading edge attack angle of some diffuser blades increases, the reverse pressure gradient in the flow direction increases, a high-entropy area appears on the suction surface, and the airflow is easier to separate, so that the stall occurs in a larger flow condition, and the surge boundary moves to the direction of high flow;the volute has no appreciable effect on the compressor blockage boundary.