Flow and heat transfer characteristics of droplet-shaped pin-fin channel under rotational conditions

IF 5 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer Pub Date : 2025-05-09 DOI:10.1016/j.ijheatmasstransfer.2025.127220

Haiwang Li , Xiangshang Qi , Xuejiao Zhang , Ruquan You , Li Wan , Zhihua Wei

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引用次数: 0

Abstract

The pin-fin structure is widely used for internal cooling in engines. Studying the performance of different pin-fin structures is meaningful. This investigation conducts experimental research on a straight droplet-shaped pin-fin channel. Furthermore, numerical methods are adopted to assist in the analysis of experimental phenomena. The influence of different dimensionless parameters on distribution and variation of the heat transfer coefficient (HTC) and the thermal performance factor (TPF) within the channel under rotating conditions are the core objective of this study. The dimensionless parameters in this investigation is Re = 10,000–70,000, Ro = 0–1.0, r/D = 25.67–52.33, TR = 0.04–0.22, and Buo = 0–2.55.

According to this investigation, rotation weakens heat transfer on the leading surface (LS) while increasing it on the trailing surface (TS) by 10 %-20 %. Rotation can enhance the TPF of the channel under low-Re condition, and causes a decrease of 0–10 % in the TPF of the LS under high-Re condition. The effect of rotation on the TPF of the TS is minor within the channel at X/D ≤ 4, whereas rotation can increase the TPF of the TS by 0–10 % at larger X/D condition. The effect of r/D on heat transfer also be discussed. When Re = 5000, rotational radius ratio of 52.33 leads to a 8.6 % increase in the average Nu compared to the rotational radius ratio of 25.67. Similarly, when Re = 15,000, there is a 1.5 % enhancement observed. The droplet-shaped pin-fin are less affected by TR variations compared to circular pin-fin, and higher TR decreases the TPF of the channel. The study finally explored the impact of Buo on experimental accuracy and found that when Re and Buo are identical, there is an obvious difference in Nu, with a minimum variation of 34.6 %, during variations in Ro, r/D, and TR. To obtain accurate HTC, it is essential to maintain similar ranges for the dimensionless parameters including Re, Ro, r/D, TR, D. These findings enhance the overall comprehension of HTC and TPF within the internal cooling channel, providing valuable insights for optimization endeavors.

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旋转条件下液滴状针翅通道的流动与换热特性

翅片结构广泛用于发动机的内部冷却。研究不同翅片结构的性能是有意义的。本研究对直滴状的针翅通道进行了实验研究。此外，还采用数值方法辅助实验现象的分析。在旋转条件下，不同的无量纲参数对通道内传热系数（HTC）和热性能因子（TPF）分布和变化的影响是本研究的核心目标。本次调查的无量纲参数为Re = 10000 ~ 70000, Ro = 0 ~ 1.0, r/D = 25.67 ~ 52.33, TR = 0.04 ~ 0.22, Buo = 0 ~ 2.55。根据这项研究，旋转削弱了前表面（LS）的换热，而使后表面（TS）的换热增加了10% - 20%。在低re条件下，旋转可以提高通道的TPF，而在高re条件下，旋转使LS的TPF降低0 ~ 10%。在X/D≤4的通道内，旋转对TS的TPF影响较小，而在较大的X/D条件下，旋转可使TS的TPF增加0 ~ 10%。讨论了r/D对传热的影响。当Re = 5000时，旋转半径比为52.33，平均Nu比为25.67增加8.6%。类似地，当Re = 15,000时，观察到1.5%的增强。液滴型销片受TR变化的影响小于圆形销片，较高的TR降低了通道的TPF。研究最后探讨了Buo对实验精度的影响，发现当Re和Buo相同时，在Ro、r/D和TR的变化中，Nu的差异明显，最小变化为34.6%。为了获得准确的HTC， Re、Ro、r/D、TR、D等无量纲参数必须保持相似的范围，这些发现增强了对内部冷却通道内HTC和TPF的整体理解。为优化工作提供有价值的见解。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

International Journal of Heat and Mass Transfer 工程技术-工程：机械

CiteScore

10.30

自引率

13.50%

发文量

1319

审稿时长

41 days

期刊介绍： International Journal of Heat and Mass Transfer is the vehicle for the exchange of basic ideas in heat and mass transfer between research workers and engineers throughout the world. It focuses on both analytical and experimental research, with an emphasis on contributions which increase the basic understanding of transfer processes and their application to engineering problems. Topics include: -New methods of measuring and/or correlating transport-property data -Energy engineering -Environmental applications of heat and/or mass transfer