湍流模型对超临界射流的数值模拟研究  

Numerical Simulation Study of Supercritical Jet Injection Characteristics by Turbulence Model

作　　者：巴金 韦武 董文志 周亭羽 BA Jin;WEI Wu;DONG Wenzhi;ZHOU Tingyu(School of Mechanical Engineering,Guizhou University,Guiyang 550000)

机构地区：[1]贵州大学机械工程学院,贵阳550000

出　　处：《计算机与数字工程》2025年第2期551-557,571,共8页Computer & Digital Engineering

基　　金：国家自然科学基金项目(编号:52066004);贵州省科技计划项目课题(编号:[2020]1Y237)资助。

摘　　要：随着内燃机燃烧效率以及清洁排放的要求,燃烧室内的温度和压力不断提高,使得燃料逐渐进入超临界状态。而燃料在超临界状态的喷射特性与传统的经典喷射模型有很大不同,不会出现射流分裂破碎等现象。论文基于大涡模拟(LES)和雷诺平均(RANS)方法,并结合BWRS真实流体状态方程建立了液氮在超临界环境下的喷射模型,研究湍流模型对超临界射流喷射特性的影响。研究结果表明:对于液氮喷雾的气态贯穿距,采用LES模型或者RANS模型,对其影响不大。RANS模型对于射流在中心轴线的密度变化梯度更大,并且在射流远端的中心密度要低于LES模型。RANS模型在射流远端径向上的扩散速率要高于LES模型。LES模型预测的射流表面具有更高的导热系数,与周围的超临界氮气传热传质效果更好。With the combustion efficiency of internal combustion engines and the requirement of clean emissions,the tempera⁃ture and pressure in the combustion chamber are increasing,making the fuel gradually enter the supercritical state.The injection characteristics of the fuel in the supercritical state are very different from the traditional classical injection model,and no phenome⁃na such as jet splitting and fragmentation will occur.This paper establishes the injection model of cryogenic nitrogen in supercritical environment based on large eddy simulation(LES)and Reynolds-averaged Navier-Stokes equations(RANS)and combines with BWRS real fluid equation of state to study the effect of turbulence model on supercritical jet injection characteristics.The results of the study show that the LES model or the RANS model has little effect on the vapor penetration of the cryogenic nitrogen spray.The RANS model has a greater gradient of density variation in the central axis for the jet and a lower central density at the distal end of the jet than the LES model.The RANS model has a higher diffusion rate in the radial direction at the distal end of the jet than the LES model.The LES model predicts a jet surface with higher thermal conductivity and better heat and mass transfer with the sur⁃rounding supercritical nitrogen.

关 键 词：超临界 大涡模拟(LES) 雷诺平均(RANS) 真实流体模型 喷雾 

分 类 号：TK16[动力工程及工程热物理—热能工程]