摘要
以五阶迎风和八阶对称格式混合差分格式求解三维可压缩滤波Navier-Stokes方程,对来流Mach数为6.0、半锥角5°的高超声速空间发展钝楔边界层转捩至完全湍流进行了大涡模拟。时间推进采用紧致存储三阶Runge-Kutta方法,亚格子尺度模型为Driest因子修正的Smagorinsky涡黏性模型。通过定常流场入口边界附近吹/吸引入不稳定扰动斜波的方法数值模拟得到了层流失稳转捩直至完全湍流的空间发展全过程。对扰动的线性、非线性增长以及湍流斑的形成和发展进行了分析,给出了转捩及完全湍流下的速度相关量统计并与实验、DNS结果进行了对比分析,计算结果与理论及实验吻合。
The transition mechanism of a hypersonic boundary layer in the conditions of high Mach number and high Reynolds number is investigated, and the evolution of instable structures is analyzed. The numerical method is large eddy simulation （LES）. The spatial transition coherent structure of a hypersonic blunt-wedge boundary layer at a free-stream Mach number of Maw = 6.0 based on free-stream velocity and a Reynolds number of Re= 2.0 × 10^6/inch is studied with a hybrid method of a fifth-order upwind compact difference and a eighth-order symmetric compact difference for the three-dimensional compressible Favre-filtered Navier-Stokes equations. The compact storage third-order explicit Runge-Kutta method is applied for time-integration. The sub grid scales are formulated according to the modified Smagorinsky eddy-viscosity model. Based on the linear stability theory, a particular perturbation of blowing and suction is introduced close to wall as unstable disturbances on the inflow boundary. The obtained flow process is divided into three stages： the linear and weakly nonlinear growth of disturbance, transition,and full turbulence. The result presents that LES can simulate hypersonic blunt-wedge transition well.
出处
《航空学报》
EI
CAS
CSCD
北大核心
2007年第2期269-274,共6页
Acta Aeronautica et Astronautica Sinica
基金
国家安全重大基础研究(51324)资助项目
关键词
转捩
湍流
可压缩边界层
大涡模拟
transition
turbulence
compressible boundary layer
large eddy simulation
