矩形截面螺旋通道内流体绕管流动特性的数值研究

Using Fluent software and numerical calculation method, a hybrid calculation model was established to study the heat-transfer characteristics of fluid flow around the heat-exchange tube in a spiral channel and a straight channel, and to compare the thermal characteristics of fluid flow around a heat-exchange tube in above two channels. Results show that the inner detachment angle of spiral channel is smaller than outer detachment angle, and the detachment points are distributed in the turbulent region. The Nu_m of spiral channel is higher than that of straight channel; in the case of β=15° and 20°, compared with straight channel heat-exchange tube, the Nu_m of spiral channel heat-exchange tube is respectively 4.0% and 4.5% higher on the windward side, and 14% and 18% higher on the leeward side. Around β=40°, the heat-transfer performance is maximally enhanced for the tube in spiral channel, when the tube wall Nu_m is increased by 19%, compared with the straight channel.