期刊
JOURNAL OF FLUID MECHANICS
卷 850, 期 -, 页码 5-17出版社
CAMBRIDGE UNIV PRESS
DOI: 10.1017/jfm.2018.465
关键词
compressible flows; multiphase and particle-laden flows; vortex flows
We propose a dynamical vortex definition (the 'lambda(rho) definition') for flows dominated by density variation, such as compressible and multi-phase flows. Based on the search of the pressure minimum in a plane, lambda(rho) defines a vortex to be a connected region with two negative eigenvalues of the tensor S-M + S-v. Here, S-M is the symmetric part of the tensor product of the momentum gradient tensor del (rho u) and the velocity gradient tensor del u, with S-v denoting the symmetric part of momentum-dilatation gradient tensor del(v rho u), and v equivalent to del.u, the dilatation rate scalar. The lambda(rho) definition is examined and compared with the lambda(2) definition using the analytical isentropic Euler vortex and several other flows obtained by direct numerical simulation (DNS) -e.g. liquid jet breakup in a gas, a compressible wake, a compressible turbulent channel and a hypersonic turbulent boundary layer. For low Mach number (M less than or similar to 5) compressible flows, the lambda(2) and lambda(rho) structures are nearly identical, so that the lambda(2) method is still valid for low M compressible flows. But, the lambda(rho) definition is needed for studying vortex dynamics in highly compressible and strongly varying density flows.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据