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通过求解三维非定常雷诺平均N-S方程模拟某跨音速高压涡轮非定常流场,研究涡轮内非定常流动特征。通过对静子尾迹及静子尾缘激波和转子叶排之间的相互干涉过程进行详细分析,发现定常/非定常模拟方法获得的涡轮总体性能参数基本一致但流场存在较大差异。静子尾迹是导致涡轮流场非定常性的重要因素之一:在转子叶栅通道中部和下部,静子尾迹和转子叶片附面层及下通道涡发生明显干涉,并导致通道中下部损失周期性波动幅度较大,此外尾迹和下通道涡间的干涉作用在转子尾缘处诱导出高频脱落涡。静子尾缘激波也是导致涡轮流场非定常性的原因之一,激波和转子叶片作用形成复杂的波系结构,对涡轮流场影响显著:一方面激波/附面层干涉导致转子和静子的吸力面产生周期性变化的高温区域;另一方面激波撞击叶片导致叶片表面的气流在激波后出现分离,对转子静压分布产生影响,使得转子叶片表面载荷出现明显的非定常性,进而导致涡轮输出功的周期性波动十分剧烈。
The unsteady flow field in a transonic high-pressure turbine is simulated by solving three-dimensional unsteady Reynolds averaged N-S equations to study the unsteady flow characteristics in a turbine. Through the detailed analysis of the interaction process between stator wake and stator trailing shock and rotor blade row, it is found that the general performance parameters of turbine with steady / unsteady simulation are basically the same, but the flow field is quite different. Static stator wake is one of the most important factors leading to the unsteady flow field of turbine. In the middle and lower part of the rotor cascade, the wake of the stator and the rotor blade laminar layer and the lower channel vortex interfere obviously and cause periodic loss In addition, the interaction between the wake and the lower vortex induces a high-frequency shedding vortex at the rotor trailing edge. The stator wake shock is also one of the reasons leading to the unsteady turbulent flow field. The shock wave and the rotor blade form a complex wave structure, which has a significant impact on the turbine flow field. On the one hand, the shock wave / On the other hand, the impact of the shock wave on the blade causes the air flow on the blade surface to separate after the shock wave, which affects the static pressure distribution of the rotor, resulting in obvious unsteady load on the surface of the rotor blade , Resulting in cyclical fluctuations in turbine output is very intense.