摘要
采用数值模拟的方法对螺纹管管内的流动与换热情况进行了研究.针对不同槽深螺纹管在不同雷诺数下内部的速度矢量场进行了对比分析,详细研究了螺纹对管内两种流动方式及其对流动和换热的影响.研究结果表明,随着槽深e的增加,旋流不断加强,减薄边界层,涡流引起的扰动也逐渐增强,并加强了管内流体径向混合,因而强化了螺纹管的换热能力.但是当槽深e继续增加到一定程度时,旋流的增强主要集中于对换热影响较小的中心区域,而对换热影响较大的壁面附近的变化很小,这时旋流对换热的强化影响很小;此时涡流核心区又会逐渐形成死流,从而弱化换热,并且随着槽深e的增大,死流区逐渐扩大.
The flow and heat transfer in spirally fluted tubes were investigated numerically.The velocity vector fields in spirally fluted tubes with different groove depths under different Reynolds numbers were compared.The influences of the thread groove on the two types of flows and heat transfers were investigated.It is found that the spiral flow is enforced with the increasing groove depth “e ”,the disturbance caused by eddy is gradually enhanced and the heat transfer in the pipe also increases.However,when e rises up to a certain value,the enhancement of spiral flow concentrates mainly in the center region of pipes which has little effect on heat transfer.In the area near the wall where the flow type has a great influence on heat transfer,the change of spiral flow is small and therefore it has little effect on heat transfer enhancement.The center of the eddy becomes a ‘still zone’which weakens the heat transfer.In addition,when e is kept increasing,the still zone enlarges.
出处
《上海理工大学学报》
CAS
北大核心
2016年第2期133-136,141,共5页
Journal of University of Shanghai For Science and Technology
基金
国家自然科学基金资助项目(51476102)
关键词
螺纹管
螺旋流动
传热
数值模拟
spirally fluted tube
spiral flow
heat transfer
numerical simulation
