亚声速等膨胀平面射流的初始流场结构

基于大涡模拟方法与5阶精度混合TCD/WENO格式,对等膨胀射流在马赫数为Ma=0.6条件下的初始流场结构进行了数值模拟。数值结果描述了射流等膨胀过程中,射流初始流场的形成、变化及发展过程。并发现了射流初始流场中涡核为射流失稳的起始点,研究了射流混合层与涡核剪切层上涡的产生、发展与破碎以及它们卷吸环境气体并与射流气体混合的整个过程,揭示了射流初始过程中涡核与涡环直径的变化趋势,得到了射流轴向速度与压力的分布。数值结果可为相关发动机的设计提供重要参考。

Initial Flow Structures of an Iso-expanded Subsonic Plane Jet

Based on LES(Large-eddy simulation),combined with the 5th-order hybrid TCD-WENO scheme,the initial flow field of an iso-expanded subsonic jet at Ma=0.6 was simulated numerically.The numerical results described the formation,variation and development process of the initial structures of the jet flow.Moreover,it is found that the vortex core is the original source of the jet flow instability,and the generating,developing and breaking processes of the mixing layers of the jet flow and the shear layer of vortex core,and their entrainments of environment gases as well as the mixing processes were studied.The developing tendencies of the vortex ring and its core diameter were shown.The streamwise velocity and pressure distributions of the jet flow along with its symmetrical axis were obtained.The numerical results can provide important guide for some corresponding engine design.