摘要
针对跨声速压气机叶栅风洞试验过程中存在的唯一冲角问题,通过开展不同来流马赫数以及不同背压条件下的平面叶栅风洞试验测量和数值模拟研究,阐明了高亚声和超声来流条件下跨声速压气机叶栅栅前流场唯一性不同的形成机制,分析了静压比对叶栅流动状态和激波结构的影响机制。研究结果表明:跨声速叶栅在低背压条件下叶栅内激波结构为双激波模式,表现为前缘脱体激波和通道正激波,随着背压的增加,通道激波位置逐渐前移并最终与脱体激波合并,形成单激波模式。超声速来流条件下,栅前流场参数受激波-膨胀波波系的影响呈现出波浪分布,其测量位置至少应距离叶栅前额线50%弦长。理论分析结果表明:跨声速叶栅的唯一冲角现象可扩展到高亚声速状态,但其物理机制有所不同,超声速状态下进口气流角取决于来流马赫数和叶栅入口几何形状,而亚声速状态下进口气流角取决于来流马赫数和叶栅喉部面积。随着静压比的提高,跨声速叶栅运行状态经历堵塞状态-溢出状态-设计状态的转变,在来流马赫数为1.10时总压损失系数由0.175递减为0.082,降幅超过50%。叶栅变背压试验结果表明,静压比超过1.379时流场三维效应增强,影响到叶栅流动的周期性,并且栅后节流板会干扰到尾迹参数的测量。该研究结果有助于理解跨声速叶栅运行状态、激波结构以及栅前流场唯一性机制,同时可对跨声速叶栅试验起到指导作用。
For the unique incidence problem in the wind tunnel experiments of the transonic compressor cascade,by conducting experimental measurements and numerical simulations under different inflow Mach number and back pressure condition,this study elucidates the formation mechanism of the uniqueness in the inlet flow field of the cascade under the subsonic and supersonic inflow conditions,and analyzes the impact mechanism of the static pressure ratio on the cascade flow states and shock wave structures.The research results indicate that under low back pressure conditions,the shock wave within the transonic cascade exhibits a dual shock wave pattern,characterized by a leading edge detached shock wave and a passage normal shock wave.As the back pressure increases,the position of the passage shock wave gradually moves forward and eventually merges with the detached shock wave to form a single shock wave pattern.Under supersonic inflow conditions,the inlet flow field parameters are influenced by shock wave-expansion wave systems and present a wave distribution.The measuring position of the inlet flow parameters should be at least 50%chord length distance from the leading edge of the cascade.Theoretical analysis reveals that the unique incidence phenomenon of the transonic cascade can be extended to high subsonic inflow conditions,but with different physical mechanisms.In supersonic states,the inlet airflow angle depends on the inflow Mach number and the geometric shape of the cascade inlet,whereas in subsonic states,the angle depends on the inflow Mach number and the throat area of the cascade.As the static pressure ratio increases,the transonic cascade operation undergoes the transition from a blocked state to a spilling state and eventually to a design state,with the total pressure loss coefficient decreasing monotonically from 0.175 to 0.082 at the incoming Mach number of 1.10,with a decrease of more than 50%.The results of the cascade variable back pressure experiments indicated that the three-dimensional effects of the flow field were enhanced when the static pressure ratio exceeded 1.379,which affected the periodicity of the cascade flow,and the cascade trailing edge throttle plate interfered with the measurement of wake parameters.These findings aid in comprehending the variations in the transonic compressor cascade’s operation state,shock wave structure,and unique incidence flow field.They can also serve as guidance for transonic cascade experiments.
作者
孟凡杰
宫超玄
唐洁
李景银
魏巍
郭朋华
MENG Fanjie;GONG Chaoxuan;TANG Jie;LI Jingyin;WEI Wei;GUO Penghua(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Institute of Air and Space Technology,China Aerodynamic Research and Development Centre,Mianyang,Sichuan 621000,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2024年第7期13-25,共13页
Journal of Xi'an Jiaotong University
基金
国家科技重大专项资助项目(2017-Ⅱ-0007-0021)。
关键词
压气机叶栅
激波
唯一冲角
静压比
compressor cascade
shock wave
unique incidence
static pressure ratio
作者简介
孟凡杰(1995-),男,博士生;通信作者:李景银,男,教授,博士生导师。
