摘要
采用圆管中心层流充分发展段中心流等截面分层填充金属多孔介质以实现强化传热,建立了流动与传热数学模型,并着重分析了三种新型强化传热管的速度、温度分布及传热综合性能。结果表明,与光管相比,填充金属多孔介质后,管中心流体温度更均匀,壁面附近流体的温度梯度更大,圆管中心流体速度分布趋于平坦,壁面附近流体速度梯度增大,壁面与流体间的换热显著增强;对三种强化传热管,在两区域内填充孔隙率相同的多孔介质,可望得到较高的综合性能指标值。
The inner part of the fully-developed laminar tube flow was filled with high-porosity metallic porous media divided into layers with equivalent size of cross section to realize the aim of heat transfer enhancement, and mathematical models for its flow and heat transfer were established. Simulation results indicate that compared with those in clear tube, the temperature of flow in the inner part of the tube filled with metallic porous media becomes more uniform; the temperature gradient is larger in the boundary flow. More over, the flow velocity profile in the inner part of the tube turns flat while the velocity gradient of the boundary flow increases. All these changes help to enhance the heat transfer between the tube and the wall. In addition, in order to increase the performance evaluation criteria value of the three types of enhanced tubes, it is appropriate to fill the tube with equivalent porosity into the two layers.
出处
《水电能源科学》
北大核心
2009年第6期223-226,共4页
Water Resources and Power
基金
教育部重点研究基金资助项目(104127)
关键词
强化传热
多孔介质
性能评价准则
孔隙率
enhanced heat transfer
porous medium
performance evaluation criteria
porosity rate
