摘要
激波与湍流相互作用(shock-turbulence interaction,STI)是空气动力学研究中的一个基础问题.基于格心有限差分法(cell-centered finite difference method,CCFDM)求解器Helios,采用五阶加权紧致非线性格式(weighted compact nonlinear scheme,WCNS)对各向同性湍流通过正激波的情形进行直接数值模拟(direct numerical simulation,DNS).对湍流相关物理量进行统计,分析结果表明,在湍流中波后的密度、温度和压力较无湍流情形下略小,而速度则略大,均在波后呈现短暂过冲然后缓慢向理论值逼近的变化趋势;波后流向雷诺应力突降随之快速增长又衰减,呈现非单调变化趋势,线性相互作用分析(linear interaction analysis,LIA)将其归结为波后能量从声模式转移为涡模式方式,与流向不同,横向雷诺应力突增后单调衰减,波后雷诺应力各向异性明显且随下游距离逐渐增强;波后湍动能突增后呈现非单调变化趋势;泰勒微尺度和Kolmogorov尺度过激波后均明显减小,说明波后湍流长度尺度变小,从而对波后网格的分辨率提出了更高的要求;密度、温度和压力过激波后脉动均方根均增加,密度和压力脉动强度减小,温度脉动强度增大.
Shock-turbulence interaction is a kind of important fundamental problem in aerodynamics. Based on solver Helios which applies cell-centered finite difference method (CCFDM), using fifth-order weighted compact nonlinear scheme (WCNS), we conducted direct numerical simulation (DNS) of the situation where isotropic turbulence passes through a normal shock wave. Turbulence statistics are calculated for analysis. We found after shock, density is a little lower than its non-turbulent value, so do temperature and pressure, on the contrary, longitudinal velocity is a little higher than its non-turbulent value. The commonality is that they all show an overshoot immediately behind the shock, after that they gradnally approach towards their non-turbulent values along with downstream distance. Longitudinal Reynolds stress suffers a sudden decrease and increases rapidly followed by decaying. This evolution characteristics is captured in linear interaction analysis (LIA) and a transfer of energy from acoustical to vertical modes behind the shock is thought to be accounted for it according to this analysis. Different from longitudinal Reynolds stress, Transverse Reynolds stress suffers a sudden increase then decay monotonically. Anisotropy of Reynolds stress is apparent after shock, and itgradually increases as downstream distance increases. Turbulent kinetic energy suddenly increases and then evolves non-monotonically. Taylor microscale and Kolmogorov scales apparently decrease after shock, indicating the decrease of turbulent length scales, which leads to a requirement of higher resolution of mesh in this zone to solve the flow field. After shock, the root-mean-squares of density, temperature and pressure fluctuations are enhanced, and intensities of density and pressure decrease while intensity of temperature increases.
作者
洪正
叶正寅
Hong Zheng;Ye Zhengyin(School of Aeronautics,Northwestern Polytechnical University,Xi'an 710072,China)
出处
《力学学报》
EI
CSCD
北大核心
2018年第6期1356-1367,共12页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金资助项目(11732013)
关键词
激波湍流相互作用
格心有限差分法
直接数值模拟
统计分析
shock-turbulence interaction
cell-centered finite difference method
direct numerical simulation
statisticsanalysis