真实运行状态下叶顶间隙尺寸波动对跨声速转子气动性能的影响研究

Effects of Tip Clearance Size Fluctuation in Actual Operations on Aerodynamic Performance of a Transonic Rotor

关键词:  不确定性量化  跨声速压气机转子  叶顶间隙  气动性能  非嵌入式混沌多项式

Key words:  Uncertainty quantification  Transonic compressor rotor  Tip clearance  Aerodynamic performance  Non-intrusive polynomial chaos

摘要:

为分析跨声速转子实时波动的叶顶间隙尺寸对气动性能的影响，对跨声速压气机转子真实运行状态下一个稳定工况实时波动的叶顶间隙数据进行统计分析，获得了叶顶间隙尺寸的总体水平、波动幅值和概率分布形式。以跨声速压气机转子NASA Rotor 37为研究对象，采用非嵌入式混沌多项式不确定性量化方法，对100%转速下近失速和峰值效率两个工况施加相同叶顶间隙波动对跨声速转子气动性能的影响进行了不确定性量化分析。结果表明，真实运行状态下叶顶间隙波动对气动性能的总体水平无影响，但会缩小喘振裕度3.75%；近失速工况对叶顶间隙波动更为敏感，各参数的相对波动幅值均较峰值效率工况有所增大，等熵效率受叶顶间隙波动的影响比质量流量和总压比大；近失速工况下叶顶间隙波动在叶高方向上的影响范围和强度均大于峰值效率工况，98%叶高位置处静压系数和总压损失系数最大相对波动幅值分别可达14.84%和5%。峰值效率工况下流场中的不确定性主要由叶顶泄漏流及其与激波相互作用引起；而近失速工况下流场当中的不确定性则是由激波和吸力面分离流动起主要作用。

Abstract:

To analyze the tip clearance size fluctuation on the aerodynamic performance of the transonic compressor rotor in actual operations, the real measurement data of tip clearance size were obtained from a transonic compressor working in a steady operating condition. The mean value, fluctuation amplitude and probability distribution of were extracted by statistical analysis. NASA Rotor 37 was chosen as research object to study the influence of the same tip clearance fluctuation at peak efficiency and near stall conditions at 100% rotating speed. Non-intrusive polynomial chaos method based on measurement data was adopted to quantify the uncertainty of aerodynamic performance. The results show that the tip clearance fluctuation has little effect on the overall aerodynamic performance but the surge margin decreases 3.75%. The transonic rotor at near stall condition is more sensitive to the tip clearance fluctuation, meanwhile, the fluctuation amplitude of the aerodynamic parameters is larger than the peak efficiency condition. The isentropic efficiency is the most sensitive parameter compared with mass flow rate and total pressure ratio. The tip clearance fluctuation affects wider range in span direction at the near stall condition compared with the peak efficiency condition. The biggest relative fluctuation amplitude of static pressure coefficient and total pressure loss coefficient at 98% span are 14.84% and 5%, respectively. The uncertainty of flow field at the peak efficiency condition is directly affected by the uncertain tip leakage flow and tip leakage flow interacting with shock wave. At the near stall condition, the uncertainty in the flow field is mainly affected by shock wave and the separation flow near the suction surface.