跨/超临界射流中湍流和热力学的作用机理研究  

Study on the Interaction Mechanism of Turbulence and Thermodynamics in Trans-/Supercritical Jets

作　　者：马杰 刘宏升[1] 解茂昭[1] MA Jie;LIU Hongsheng;XIE Maozhao(Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学海洋能源利用与节能教育部重点实验室,大连116024

出　　处：《工程热物理学报》2024年第8期2517-2523,共7页Journal of Engineering Thermophysics

基　　金：国家重点研发计划(No.2023YFB3813500)。

摘　　要：基于开发的跨/超临界喷雾模型,本研究对跨/超临界低温液氮射流进行了大涡模拟。首先讨论了不同亚格子模型的影响;其次,不同工况下的射流动力学与热力学相互作用被分析。结果表明:不同亚格子模型对射流动力学的影响主要体现在射流远场区,这与射流热力学方面的差异不同。跨/超临界射流存在两个重要特征:一方面,固有的高密度梯度会阻碍射流的径向波动,延缓射流的分解;另一方面,跨临界射流特有的伪沸腾现象会抑制射流与环境流体的混合。跨临界射流中的隔热层会阻碍射流与环境流体之间的有效热交换;然而,局部的湍流–热力学相互作用会导致隔热层扭曲和弱化,这反过来会促进流体动力学不稳定性,从而加速所谓指状结构的拉伸和溶解。Based on the developed trans/supercritical spray model,the Large eddy simulation of trans-/supercritical cryogenic liquid nitrogen jet was carried out in present work.The effects of dif-ferent sub-grid models on the trans-/supercritical jet is first discussed.Then,the interaction between jet dynamics and thermodynamics under different conditions is analyzed.The results show that the effects of different sub-grid models on the jet dynamic is mainly reflected in the downstream region of jet,which is different from the difference in jet thermodynamics.There are two important charac-teristics of trans-/supercritical jets:On the one hand,the inherent high density gradient will hinder the radial fluctuation of jet and delay the jet breakup;On the other hand,the unique pseudo-boiling phenomenon in the transcritical jet will lead to isothermal expansion of jet and inhibit the mixing of jet with the ambient fluid.The thermal-shield layer of transcritical jets will hinder the effective heat exchange between the jet and ambient fluid.However,the local turbulence-thermodynamic interactions can lead to distortion and weakening of the thermal-shield layer,which in turn pro-motes hydrodynamic instability and accelerates the stretching and dissolution of the finger-like structure.

关 键 词：跨/超临界喷射 真实流体模型 伪沸腾 亚格子模型 高压湍流–热力学相互作用 

分 类 号：TK123[动力工程及工程热物理—工程热物理]