Purpose

This study aims to explore the 3 D separated flow fields and heat transfer characteristics at the end wall of a serpentine channel with various turn clearances using topological analysis and critical points principles of three-dimensional vortex flow.

Design/methodology/approach

This aims to explore the 3 D separated flow fields and heat transfer characteristics at the end wall of a serpentine channel with various turn clearances using topological analysis as well as critical points principles of three-dimensional vortex flow.

Findings

The endwall heat transfer in the narrow spacing passage is significantly stronger than that in a wide spacing channel. As the gap clearance is kept at 0.87 times of the hydraulic diameter, the endwall heat transfer and thermal performance can be accordingly enhanced with low pressure drops, which is because a relatively strong concentrated impingement flow for the medium gap clearance helps to restrain the downstream fluid flow and enhance the shear effect of the secondary flow.

Practical implications

The numerical results can be applied in designing sharp turn of serpentine channel in heat exchangers, heat sinks, piping system, solar receiver and gas turbine blades.

Originality/value

The evolution mechanism of the vortices in the turning region under different gap clearance was analyzed, and thermal enhancement characteristics were predicted innovatively using topological analysis method.

中文翻译：

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基于拓扑分析的分隔壁到端壁距离对双通道涡流结构和传热特性的影响

目的

本研究旨在利用三维涡流的拓扑分析和临界点原理，探索具有各种转弯间隙的蛇形通道端壁的3D分离流场和传热特性。

设计/方法/方法

本研究旨在利用拓扑分析以及三维涡流的临界点原理，探索具有各种回转间隙的蛇形通道端壁的 3D 分离流场和传热特性。

发现

窄间距通道的端壁传热明显强于宽间距通道。由于间隙间隙保持在水力直径的0.87倍，因此端壁传热和热性能可以在低压降的情况下相应增强，这是因为中等间隙间隙的较强的集中冲击流有助于抑制下游流体流并增强二次流的剪切作用。

实际影响

数值结果可用于换热器、散热器、管道系统、太阳能接收器和燃气轮机叶片中蛇形通道的急转弯设计。

原创性/价值

分析了不同间隙间隙下转向区涡旋的演化机理，创新性地采用拓扑分析方法预测了热增强特性。