三维跨声速多级压气机内确定应力耦合问题研究

Research on Deterministic Stress Coupling in Multi-Stage Transonic Compressor

关键词:  压气机  非定常计算  确定应力  耦合  边界条件

Key words:  Compressor  Unsteady calculation  Deterministic stresses  Couple  Boundary condition

摘要:

为开展确定应力耦合效果的研究，基于三维定常Denton程序发展了三维非定常计算程序，以多级跨声速压气机近失速点为算例，进行确定应力耦合精度的研究。除定常计算和非定常计算外，还采用了三种计算方式，分别是多级环境下非定常时均方程耦合确定应力的解(COU2)，提取非定常精确解时均的值作为S2进口边界条件进行单独S2计算域的定常计算(ST1)；在ST1基础上耦合确定应力的解(COU1)。结果表明:三维压气机算例中出口总压和马赫数的径向曲线对比显示COU1的误差水平分别为ST1的53%和34%；验证了确定应力项的耦合可以使定常计算的结果更接近非定常计算的时均解；对比发现ST1计算精度较COU2高，误差水平分别降低至37%和32%。说明在该算例中精确的边界条件比精确的确定应力发挥更大的作用。非定常时均结果中近压力面的熵值比近吸力面的熵值要高，反映出非定常相互作用中上游尾迹向压力面迁移的效应，Adamczyk时均方程耦合确定应力后得到了类似的结果。

Abstract:

Three-dimensional unsteady solvers have been developed based on three-dimensional Denton steady solver to conduct study of deterministic stress coupling effect. Researches on deterministic stress coupling have been conducted on multi-stages transonic compressor near stall point. Three calculation methods are adopted in addition to the steady and unsteady calculation，that is，COU2，which means solution of deterministic stress coupling equation under multistage circumstance，ST1，which means solution of steady equation in S2 calculation field using time-accurate solution as inlet boundary condition，COU1，which means solution of deterministic stress coupling equation based on ST1. The radial curves of total pressure and Ma number in a three-dimensional compressor case show that the error level of COU1 is 53% and 34% of ST1 respectively. It is verified that the coupling of the deterministic stress can make the calculation result more close to the unsteady calculation. The comparison shows ST1 calculation accuracy is higher than that of COU2，and the error level is reduced to 37% and 32% respectively. It shows in this simulation case，the exact boundary condition is more than the exact determination stress. In unsteady result，pressure side showed higher entropy value than suction side，this reflects migration effect to the pressure surface of rotor wake during its unsteady sweeping. And the coupling result is better to capture the phenomenon.