中文摘要：

运用计算流体力学（Computational fluid dynamics,CFD）技术数值模拟带径向进气室的某石化离心压缩机级内部的流动情况,结果表明进气室内部的流场较为复杂,存在较大的旋涡结构,流动损失较大,并造成在叶轮进口处存在气流畸变,因此进气室的结构形状对整机的性能影响显著。为改善进气室内部的流动情况和提高级的性能,发展一种基于CFD技术的数值优化方法,并对该进气室的几何形状进行了优化设计。优化后的整机外特性整体得到了改善,在保证质量流量和总压比不低于初始值的约束条件下,设计工况点的整机等熵效率提高了1.26%。对比分析优化前后整机内部的速度、熵和总压等参数分布,发现优化模型内部的流动结构更为合理,流动损失更小。优化结果也验证了该优化设计方法的有效性。

英文摘要：

Numerical simulation and analysis of the flow structure inside a centrifugal compressor radial inlet are carried out by using computational fluid dynamics（CFD） technique.The results show that the flow structure consisting of some large vortices is complicated,which leads to flow distortion generating at the impeller inlet and seriously degrades the stage performance.A numerical optimization approach to the radial inlet,based on CFD technique,is developed to improve flow structure and reduce flow loss,and applied to the shape optimization of a centrifugal compressor inlet.A 1.26% improvement of the objective function,isentropic efficiency of the compressor,is obtained,while satisfying the constraint conditions that the mass flow and pressure ratio are not less than those of the original one.The optimization results also show that the developed approach is effective for the optimization design of the centrifugal compressor radial inlet.