摘要
采用SIMPLE算法和RNGk-ε湍流模型,通过求解三维N-S方程和能量方程,对雷诺数为10 000和冲击高度为4倍喷管水力直径的矩形管湍流冲击射流进行了数值模拟。结果发现在冲击面附近的射流横截面上,伴随着两个反向旋转涡对的出现,形成了主流速度的两个偏心峰值。分析认为双偏心速度峰值的形成是由冲击面产生的涡量向上游截面扩散而引起的。温度场和冲击面局部Nu数分布的研究结果表明:射流的传热特性受流动结构的控制,采用矩形管湍流射流可以获得较大的冲击区和较均匀的冷却效果。
By employing algorithm SIMPLE and a RNG k-ε turbulent model and through the solution of a three-dimensional N-S equation and energy equation a numerical simulation was performed of a rectangular-tube turbulent impinging jet flow with Reynolds number of 10000 and an impingement height of 4 times of nozzle hydraulic diameter. It has been found that at the jet flow cross-section near the impingement surface accompanied by the appearance of two counter-rotating vortex pairs there emerge two eccentric peak values of main stream velocity. An analysis shows that the formation of the dual-eccentric velocity peak values is caused by the vorticity upstream diffusion produced by the impingement surface. An investigation of the temperature field and the local Nusselt number distribution of the impingement surface indicates that heat transfer characteristics of the jet flow are controlled by the flow structure and the use of a rectangular-tube turbulent jet flow can result in a relatively large impingement zone and more uniform cooling effectiveness.
出处
《热能动力工程》
EI
CAS
CSCD
北大核心
2005年第5期474-477,共4页
Journal of Engineering for Thermal Energy and Power
关键词
矩形管冲击射流
数值模拟
偏心峰值
传热
rectangular-tube impingement jet,numerical simulation,eccentric peak value,heat transfer
