Numerical Researches on Shocklets of the Three Dimensional Temporal Developing Mixing Layer where Mc=0.8
In this paper, a fourth order scheme based on frequency spectrum relation preservation and developed boundary processing methods are used to make simulations on the three dimensional temporal developing mixing layer where the convective Mach number Mc=0.8.Span-wise boundary processing, which is an important factor in three dimensional simulations, is comparatively investigated. Periodic boundary condition is adopted basically in span-wise direction and four specific manners are compared: 1) Non initial span-wise disturbances are added on the span-wise velocity; 2) Two initial span-wise disturbances are added on the span-wise velocity; 3) Three initial span-wise disturbances are added on the span-wise velocity; 4) Random disturbances are added on the span-wise velocity. Shocklets are discovered on four cases, and differences are found when different initial disturbing ways are adopted. Simulations show: 1) Three dimensional shocklets induced by vortices exist in the mixing layer; 2) For the first manner, shocklets develop in two dimensional ways,and they evolve dynamically following the enlarging-shrinking-re-enlarging way; 3) For the second and third manner, the development of vortex experiences a process of vortex splitting,in which one vortex evolves into two vortexes. The axes of vortices forms a ring-like structure; the first generated shocklet will degenerate gradually in the process, and two new shocklets are generated by two splitting vortexes, and dual-shocklets are observed in the flow field; the nonlinear developing rates of the mixing layer differ by different period number of initial span-wise disturbances, differences exist in details of evolutions also; 4)For the fourth manner, although three-dimensional effects appears about the development of vortex axes, the three-dimensional structures develop slowly from the whole view, which are different from the way in the second and third manner.
Qin Li Hanxin Zhang Junrong Luo
China Aerodynamic Research and Development Center,Mianyang,Sichuan,621000
国际会议
西安
英文
279-292
2006-08-19（万方平台首次上网日期，不代表论文的发表时间）