紊流模式中的耗散相关和能耗率

On Turbulent Dissipation Correlation and Turbulent Dissipation Rate in Turbulence Model

在前人研究的成果———将耗散相关εｉｊ 和能耗率ε分解为非均匀部分和均匀部分———的基础上，进一步将均匀部分分解为主要部分即各向同性部分和剩余部分．分析了各向同性部分εｈ 与脉动能ｋ 、横向微比尺λｇ 的关系，指出εｈ 随着脉动能ｋ 的取值，落在阻力平方区、过渡区和阻力线性区等范围，提出了可以代替紊流模式中并不精确的能耗率简化方程的算式．

Previous investigators′ study indicates that the turbulent dissipation correlation and the turbulent dissipation rate are composed of an inhomogeneous part and a homogeneous part.On the basis of this result,the homogeneous part is further composed of a main part—isotropic part and a residual part. The residual part is negligible in the turbulence model.Further more,the relation among the isotropic part ε h,fluctuating energy k and transverse differential length scale λ g is established. The study indicates that the isotropic part ε h is located in various regions of resistance, such as quadratic,transitional and linear regions.It seems that the ε—equation in k ε turbulence model can be replaced by the ε formula.