摘要
为探究氮气在多孔介质泡沫铜内的流动传热特性,应用FLUENT软件对低温制冷机冷头换热器中填充的泡沫铜进行数值模拟分析。研究了孔隙率、孔密度以及入口流速对流动、传热的影响规律,模拟结果表明,孔隙率较大、孔密度较小时,渗流性能较好,流体速度衰减较慢;随着孔隙率减小,流体压力损失增大,换热效果提高,但提高的趋势渐缓,因而可能存在压损与温降比值最小的最优孔隙率;孔密度增大,由无滑移壁面引起的压力损失增大,换热性能变差。
In order to investigate the flow and heat transfer characteristics of nitrogen gas in porous medium copper foam,a numerical simulation analysis of copper foam filled in cold head heat exchanger of cryocooler is carried on by FLUENT software.The effects of porosity,pore density,and inlet flow velocity on flow and heat transfer are studied in detail.The simulation results show that the seepage performance is good and the fluid velocity drops slowly when the porosity is large and the pore density is small.As the porosity decreases,the fluid pressure loss increases and the heat transfer performance becomes better,but the trend gradually slows.Therefore,there exists an optimal porosity with a minimum ratio of pressure loss and temperature drop.As the pore density increases,the fluid pressure loss caused by non-sliding wall increases,and the heat transfer performance deteriorates.
作者
陈曦
凌飞
CHEN Xi;LING Fei(School of Power and Energy Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)
出处
《真空与低温》
2018年第4期237-241,共5页
Vacuum and Cryogenics
基金
国家自然科学基金项目(50906054)
关键词
氮气
泡沫铜
传热
数值模拟
孔隙率
nitrogen
copper foam
heat transfer
numerical simulation
porosity
