方形通道内超临界压力二氧化碳传热恶化数值研究  

Numerical study on heat transfer deterioration of supercritical-pressure carbon dioxide in a square channel

作　　者：王彦红 李雨健 李洪伟[1] 东明[2] WANG Yanhong;LI Yujian;LI Hongwei;DONG Ming(School of Energy and Power Engineering,Northeast Electric Power University,Jilin 132012,China;School of Energy and Power Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]东北电力大学能源与动力工程学院,吉林132012 [2]大连理工大学能源与动力学院,大连116024

出　　处：《北京航空航天大学学报》2024年第6期1888-1897,共10页Journal of Beijing University of Aeronautics and Astronautics

基　　金：吉林省教育厅科技项目(JJKH20220100KJ);东北电力大学青年博士科研助推计划(BSZT02202102)。

摘　　要：基于二氧化碳代替碳氢燃料进行航空发动机热防护的应用,开展方形冷却通道内超临界二氧化碳传热恶化数值研究。探究沿通道轴向和周向的换热特征,通过温度、局部流量、流线的分布情况揭示传热恶化的原因,进一步通过边界层分析阐述传热恶化的演变过程。考察运行压力和壁面粗糙度对换热的影响机制。获得不同运行压力和壁面粗糙度下的传热恶化临界热流密度,建立临界热流密度预测准则。结果表明:通道顶部壁面附近高温类气态层、局部流量减小和流线畸变是传热恶化的特征,缓冲层出现湍动能剧减和流速峰值是传热恶化的原因。提高运行压力和增大壁面粗糙度有利于抑制传热恶化问题,所建准则(误差±15%)可实现对传热恶化临界热流密度的良好预测。Based on the use of carbon dioxide rather than hydrocarbon fuel for aero-engine thermal protection,a numerical study was conducted to examine the deterioration of supercritical carbon dioxide heat transfer in a square cooling channel.The heat transfer characteristics along the axial and circumferential directions of the channel were studied,and the reasons for the deterioration of heat transfer were explained through the distributions of temperature,local mass flux and streamlining.The evolution process of heat transfer deterioration was further elaborated by the boundary layer analysis.The effect mechanisms of operating pressure and wall roughness on heat transfer were investigated.The critical heat fluxes for heat transfer deterioration at different operating pressures and wall roughness conditions were obtained,and the critical heat flux prediction criterion was established.The findings indicate that the features of heat transfer deterioration include the streamline distortion,local mass flux reduction,and high-temperature gas-like layer close to the channel’s top wall.The severe reduction of turbulent kinetic energy and the peak of velocity in the buffer layer are the reasons for deteriorated heat transfer.Increasing the operating pressure and increasing the wall roughness can help to suppress the deteriorated heat transfer.The established criterion(error±15%)has a good prediction for the critical heat flux of heat transfer deterioration.

关 键 词：方形通道 超临界压力 二氧化碳 传热恶化 边界层 

分 类 号：V231.1[航空宇航科学与技术—航空宇航推进理论与工程]