【摘要】 采用CFD方法,对带进气回流的离心压气机进行了仿真研究,并根据试验进行了验证。为了拓宽离心压气机的稳定工作范围,根据原型机流场,改变了回流槽的几何,仿真结果表明改型能有效拓宽离心压气机的运行范围,且不明显改变压气机效率和压比.流场分析表明,改型增添的导流段对气流的导流作用引起回流槽前槽出口气流方向变化后,叶轮靠近叶顶部位轴向速度增大,叶轮前缘相对气流角降低,叶轮槽道靠近叶顶部位子午速度增加,槽道堵塞情况减轻,流动更为顺畅,是改型拓稳的原因。在80 kr·min^-1下,回流量增大,引起后槽下游轴向逆流区域扩张,叶轮吸力面分离流动加剧,是拓稳轻微失效的原因.改型机和原型机几何形状差异小,属于一种简易而有效的拓稳方案。更多还原

【Abstract】 Using CFD method, a centrifugal compressor with inlet recirculation casing treatment was investigated, and according to the compressor performance test, the simulation results are validated.In order to enhance the stable operating range of the compressor, the geometry of the recirculation groove was adjusted according to the original flow field. The simulation results showed that the modified design could effectively broaden the operating range of the centrifugal compressor, and no obvious change of efficiency and pressure ratio occurred. The flow field analysis showed that the guide function of the diversion section added by the modification affected the airflow direction, and enhanced the axial velocity of the air near the tip of the blade, which could make the relative flow angle near the front edge of the impeller decrease, the meridional velocity increase in the impeller channel tip, air blockage in the channel relief and airflow be more smooth, was an important reason for the stable operating range widening. The flow field changes showed that the recirculation flow rate increased at 80 kr·min^-1, resulting in the axial backflow region expansion at the downstream of the recirculation groove, making the separation flow at impeller suction increase slightly was the reason for the slight failure to widen the operating range at 80 kr·min^-1. The whole compressor changed little after the modification, so this scheme for widening operating range is an easy and effective one.更多还原