一、前言目前还没有一精确计算湍流流体放热的公式,特别是对液态金属。虽然液态金属是牛顿流体,但它有非常高的导热系数和低的粘性。因此,普朗特数Pr是极低的,约10~(-2)级。在湍流流动里,低Pr数的影响是:分子热传导不仅在粘性底层重要,而且在过渡层,甚至在流体核心区也重要。现在计算一般流体的放热准则—N_α数,可用熟知的雷蓓(Reynibs)比拟,普朗特(Pramdtl)比拟,卡门(Karman)比拟和马丁耐里(Martinelli)比拟等等。在这些比拟中,或没考虑涡流热扩散率,或假设了涡流热扩散率C_H“等于涡流动量扩散率ε。如果把这些比拟用于液态金属的放热计算就必须加以修正。鲁比辛(Rubesin)曾修正了卡门比拟式,德赖斯别(Van Driest)也修正了卡门比 I. INTRODUCTION Currently there is no precise formula for calculating the exothermic heat of a turbulent fluid, especially for liquid metals. Although liquid metal is a Newtonian fluid, it has a very high thermal conductivity and low viscosity. Therefore, the Prandtl number Pr is very low, about 10 ~ (-2) level. The effect of low Pr numbers in turbulent flow is that molecular heat conduction is important not only in the viscous bottom but also in the transition layer and even in the fluid core region. Now calculate the general fluid exothermic criteria -N_α number, known Reynibs, Pramdtl, Karman and Martinelli, and so on. In these comparisons, or without considering the eddy current thermal diffusivity, or assuming that the eddy current thermal diffusivity C_H "is equal to the eddy momentum diffusivity ε. If these exponentials are used in the exothermic calculation of the liquid metal, it must be corrected. Rubesin) has amended Carmen’s analogy, while Van Driest also corrected Carmen’s ratio