摘要
采用数值方法对弓形横截面螺旋半管夹套内流体的湍流流动与换热特性进行了研究。基于正交螺旋坐标系给出了夹套内换热流体充分发展的湍流流场与温度场分布。研究了雷诺数Re和无量纲曲率δ对流动阻力fRe及壁面平均换热努塞尔数Num的影响。结果表明:充分发展湍流条件下,弓形截面螺旋半管夹套的横截面上,平均轴向速度的最大值位置靠近弯曲的外壁侧;二次流为旋转方向相反的两涡结构。相同换热面积时,在0.058≤δ≤0.12,6000≤Re≤12 000的范围内,弓形截面夹套的流动阻力fRe是半圆形截面夹套的0.794～0.947倍,平均努塞尔数Num为0.86～0.98倍。
Numerical study on fluid turbulent flow and heat transfer characteristic in the half-pipe coiled jacket with arch cross section was carried out. Based on the orthogonal helical coordinate, the developed flow and temperature fields distributions were displayed. Effect of Reynolds number Re and curvature ratio on flow resistance fne and average Nusselt number Num were researched. Results show that, under the fully developed turbulent flow condition, the position of the maximum axial velocity is near the outer curved wall on the arch cross section of half-pipe coiled jacket. The secondary flow patterns are two contrary rotating vortexes. With the same heat transfer surface, fRe of the half-pipe coiled jacket with arch cross section is 0.794-0.947 times and Num is 0.86≤0.98 times those of the jacket with semi-circular cross section in the range of 0.058 ≤ 8 40.12 and 6 000 ≤Re≤12 000.
出处
《当代化工》
CAS
2012年第12期1291-1294,共4页
Contemporary Chemical Industry
基金
中央支持地方高校发展专项基金资助项目(编号:2050205)
教育部重点项目(编号:212030)
关键词
螺旋半管夹套
弓形横截面
流动阻力
换热特性
Half-pipe coiled jacket
Arch cross section
Flow resistance
Heat transfer characteristic
