论文部分内容阅读
为了揭示叶顶流场对微喷气的响应机制,深入探究微喷气扩稳机理,以高负荷轴流压气机转子为研究对象,通过求解三维雷诺时均N-S方程对其进行了5通道高精度非定常数值研究。借助时间精确的数值模拟,获得了实壁和喷气工况下压气机转子的基元级性能、总性能和叶顶流场非定常特征。研究发现,在相同流量水平下,较之实壁工况,微喷气可以显著改变叶顶流场非定常特征的时空分布,削弱叶顶流场的自激振荡幅值。微喷气通过改变叶顶瞬态攻角对流场施加影响,叶栅掠过喷嘴过程中,正对喷嘴部位的攻角会发生突降,流场扩压程度和阻塞水平关于攻角突变的响应呈现出强烈的时滞性和非线性,攻角突降所诱导出的低阻塞水平在时域内持续时间约为低攻角水平持续时间的3倍。微喷气能够提高叶栅的承载能力,增强其对时均攻角的耐受力,拓宽流量裕度,增大吸力面分离在诱发流动失稳过程中的贡献比例。
In order to reveal the response mechanism of tip flow field to micro-jet, the mechanism of micro-jet expansion is studied in detail. The high-load axial-flow compressor rotor is taken as the research object. The three-channel Reynolds averaged Navier-Stokes equations Constant Value Study. With the aid of time-accurate numerical simulation, the elemental performance, total performance and non-stationary flow field of the compressor rotor under real wall and jet conditions were obtained. The results show that under the same flow rate, micro jet can significantly change the spatio-temporal distribution of unsteady characteristics of the top flow field and weaken the amplitude of the self-oscillating flow in the tip flow field. The micro-jet affects the flow field by changing the transient attack angle of the blade tip. In the course of the blade passing through the nozzle, the angle of attack on the nozzle part will suddenly drop, and the response of the flow field and the level of blockage in response to the attack angle mutation Showing a strong time lag and non-linearity, the low obstruction level induced by the abrupt attack angle in the time domain is about 3 times the duration of the low angle of attack. Micro jet can improve the bearing capacity of cascades, enhance their tolerance to the average angle of attack, broaden the flow margin and increase the proportion of suction surface separation in the induced flow instability.