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
马杰 1刘宏升 1解茂昭1
作者信息
- 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
- 折叠
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.
Abstract
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Key words
trans-/supercritical injection/real-fluid model/pseudo-boiling/sub-grid models/turbulence-thermodynamic interaction引用本文复制引用
基金项目
国家重点研发计划(2023YFB3813500)
出版年
2024
NETL
NSTL
万方数据