Investigation on a Type of Flow Control to Weaken Unsteady Separated Flows by Unsteady Excitation in Axial Flow Compressors
Investigation on a Type of Flow Control to Weaken Unsteady Separated Flows by Unsteady Excitation in Axial Flow Compressors
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DOI：
10.1115/1.1860572
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发表时间：
2005-07
影响因子：
1.7
通讯作者：
Xinqian Zheng;Xiaoping Zhou;Sheng Zhou
中科院分区：
文献类型：
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作者：
Xinqian Zheng;Xiaoping Zhou;Sheng Zhou
通过求解高精度格式离散的非定常雷诺平均N-S方程，结果表明，周期吸气和吹气可以在较大的攻角范围内有效地控制无序的非定常分离流动，从而提高轴流压气机叶栅的时均气动性能。详细研究了非稳态激励频率、激励幅值和激励位置对系统性能的影响。有效激励频率范围较宽，且存在一个最佳激励频率，该频率几乎等于旋涡脱落的特征频率。激励幅值有一个阈值(周期吸风最大速度与自由流速度之比接近10%)和一个最佳值(接近35%)。最佳激励位置正好在分离点的上游。我们还探索了利用上游尾迹约束轴流压气机非定常分离的可行非定常致动器。
By solving unsteady Reynolds-averaged Navier-Stokes equations discretized by a high-order scheme, the results showed that the disordered unsteady separated flow could be effectively controlled by periodic suction and blowing in a wide range of incidences, resulting in enhancement of time-averaged aerodynamic performances of an axial compressor cascade. The effects of unsteady excitation frequency, amplitude, and excitation location were investigated in detail. The effective excitation frequency spans a wide spectrum, and there is an optimal excitation frequency that is nearly equal to the characteristic frequency of vortex shedding. Excitation amplitude exhibits a threshold value (nearly 10% in terms of the ratio of maximum velocity of periodic suction and blowing to the velocity of free flow) and an optimal value (nearly 35%). The optimal excitation location is just upstream of the separation point. We also explored feasible unsteady actuators by utilizing the upstream wake for constraining unsteady separation in axial flow compressors.