Abstract: Based on a shell-side periodic unit channel model, twisted-leaf tube bundle Based on a shellside periodic unit channel model;twistedleaf tube bundle support was investigated as a new type of heat transfer enhancement element;and the turbulent flow and heat transfer characteristics were studied by numerical simulationThe RNG κ-ε twoequation turbulent model was used in the studyThe coupling between pressure and velocity was solved by SIMPLEC algorithm;and the enhanced wall treatment was adopted to solve the nearwall flow and heat transferThe periodic distributions of velocity and turbulent intensity on the cross sections along the main stream were presented and the synergy between velocity and temperature fields was analyzedThe local average Nusselt number on the cross section was compared with the local synergy angleIt was found that twistedleaf support produced the 3dimension helical motion which resulted in the disruption of the continuity and stability of the fluidThe disturbing flow could promote turbulent intensity and enhance heat transfer effectivelyMeanwhile;the swirl flow changed the distributions of velocity and temperature fields;and the fundamental mechanism of heat transfer enhancement by twistedleaf was the improvement of synergy between both fields..

Key words:

旋流片, 强化传热, 数值模拟, 场协同原理

摘要：

基于壳程周期性单元流道模型;采用数值模拟方法分析了一种新型的传热强化元件——旋流片作为管间支撑物的湍流流动与传热特性。数值模拟采用重整化（RNG）κε双方程湍流模型;SIMPLEC算法进行压力和速度的耦合;壁面处理采用强化壁面处理法。分析了单元流道横截面流场和湍流强度的周期性变化;以及截面上流场和温度场的协同关系。比较了截面平均Nusselt数和平均协同角的对应变化趋势。结果表明;旋流片使流体在管束间做三维螺旋运动;破坏了流体流动的连续性和稳定性;增强湍流强度从而强化传热;同时改变了管束间流体的速度场与温度场分布;旋流片强化传热的根本机理是改善了两场的协同关系。

关键词:

旋流片, 强化传热, 数值模拟, 场协同原理