화학공학소재연구정보센터
International Journal of Heat and Mass Transfer, Vol.40, No.14, 3293-3304, 1997
Laminar Forced-Convection in the Entrance Region of Helical Pipes
In the present study, three-dimensional laminar forced flow and heat transfer in the entrance region of helical pipes have been investigated using a fully elliptic numerical method. Laminar flow and heat transfer were assumed to develop from the inlet to the outlet simultaneously. The governing equations were solved by means of a control-volume finite element method. The results presented in this paper cover a Reynolds number range of 250-2000, a pitch range of 0.0-0.6, and a curvature ratio range of 0.025-0.20. The present elliptic numerical results are compared with previous experimental data and parabolic numerical data. The developments of temperature field, main and secondary velocity fields, local and average friction factors, and local and average Nusselt numbers are given and discussed. It has been found that both the friction factor and Nusselt number are oscillatory in the entrance region of helical pipes. The pitch and Reynolds number exert different effects on the developments of the friction factor and Nusselt number than the curvature ratio.