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周向槽机匣处理作为一种有效的扩稳措施得到了广泛应用,但是缺乏对其机理的深入理解和认识。为此,在一台低速单转子轴流压气机上考察了周向单槽机匣处理随轴向位置变化的扩稳效果。实验中获得了单槽不同轴向位置的扩稳规律,在该台压气机上得出了扩稳效果最好的槽位于40%~60%轴向弦长,而当单槽位于27%轴向弦长附近时,其扩稳效果最差。在此基础上,选取了最优扩稳槽位和最差扩稳槽位进行详细的壁面非定常流场测量和尾迹测量,对比分析了光壁条件与各单槽处理机匣对叶顶间隙泄漏流和转子尾迹的影响。结果表明,采用扩稳效果最优槽位之后,周向单槽能推迟叶顶间隙泄漏流与主流交界面前移,以及减弱叶顶间隙泄漏流非定常性,且能明显增强尾迹区1BPF(叶片通过频率)的能量,同时减弱0.5BPF的能量,达到扩稳的目的。而对于扩稳效果最差槽位而言,叶顶间隙泄漏流与主流交界面直到失速前也无法跨过单槽从叶片前缘溢出,周向单槽改变了叶顶间隙内部诱发突尖失速先兆的扰动传播方式;另外,其对转子尾迹区0.5BPF和1BPF的影响也比较小,从而使得其扩稳效果减弱。
The circumferential groove casing treatment has been widely used as an effective stabilizing measure, but it lacks understanding and understanding of its mechanism. To this end, a single low-speed single-rotor axial flow compressor investigated the circumferential single groove casing treatment with the axial position of the expansion of the stabilizing effect. In the experiment, the steady expansion law of different axial positions of single groove was obtained. The best groove with 40% ~ 60% axial expansion was found on this compressor. When the single groove was located at 27% axial Near the chord, its expansion stability is the worst. On the basis of this, the optimal steady-state flow field and wake measurement are selected based on the optimum expansion slot and the worst-slip slot, and the relationship between the light wall condition and the clearance of the tip clearance Leakage flow and rotor wake influence. The results show that the circumferential single slot can delay the advance of the tip-gap leakage flow and the mainstream interface, and reduce the unsteady flow of the tip-gap leakage flow, and can significantly enhance the wake 1BPF ( Leaf pass frequency) energy, while reducing the energy 0.5BPF, to achieve the purpose of expansion. For the worst slot, the tip-tip leakage flow and the mainstream interface can not cross the single-slot overflow from the leading edge of the blade until it stalls. The circumferential single slot changes the tip-induced stalled stall in the tip clearance In addition, it has less influence on the 0.5BPF and 1BPF in the wake region of the rotor, so that its stabilizing effect is weakened.