单级近失速工况全环非定常数值模拟研究

Full-annulus Simulation Research on Single Stage Near Stall Condition

对低速轴流单级使用数值模拟的方法,研究靠近稳定边界处,压气机内详细的流场结构。对于不同叶高,随着叶片高度增加,叶片的压差越大,负荷越大。对转子前缘的压力数值探针结果进行傅里叶分析且表明,转子周向上出现了两种不同旋转周期的静压扰动,分析不同周向点的压力结果,呈现的扰动现象不同。由于叶尖间隙的存在,产生了叶尖泄漏涡,并且与主流相互作用,不同周向位置的涡系结构存在区别。对于该压气机,在近失速点附近,质量流量过小,产生的泄漏涡强度有限,最终未出现经典的旋转不稳定现象,反而更接近于叶顶自激励非定常。

By numerical simulation method for single stage, the detailed flow field structure in the compressor near the stable boundary is studied. For different blade heights, as the blade height increases, the greater the pressure difference of the blade, the greater the load. The Fourier analysis of the pressure numerical probe results on the front edge of the rotor shows that there are two static pressure disturbances with different rotation periods in the rotor circumferential direction. The pressure results at different circumferential points analysized indicate different disturbance phenomena. Due to the existence of the tip clearance, the tip leakage vortex is generated, which interacts with the main flow, and the vortex structure of different circumferential positions is different. For the compressor near the stall point, the mass flow is too small, so the leakage vortex generated is limited. The classic rotation instability does not appear in the end, but is closer to the unsteady tip self-excitation.