Micro-PIV and numerical study on influence of vortex on flow and heat transfer performance in micro arrays. (October 2019)

• Record Type: Journal Article
• Authors: Qin, Luwen; Hua, Junye; Zhao, Xiaobao; Zhu, Ye; Li, Dong; Liu, Zhigang
• Is Part Of: Applied thermal engineering. Volume 161(2019)
• Publication Date: 2019-10
• Subjects: Micro pin-fin -- Vortex -- Velocity -- Numerical simulation -- Micro-PIV; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2019.114186
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Micro-PIV measurement outcomes are in good agreement with simulation results. The vortices at the rear of circular pin-fin occurred the earliest and its structure is the largest. The shedding of vortices at the back of pin-fin are adverse to the flow characteristics. The area of vortices region is conductive to promoting the heat transfer performance of micro array. Abstract: In this paper, Micro-Particle Image Velocimetry (Micro-PIV) system has been used to visualize the flow properties of deionized water flowing across circular, ellipse and diamond micro pin-fin arrays with Reynolds number situated between 100 and 400. While Fluent 15.0 is used to simulate the velocity distribution, streamline patterns and temperature distribution around micro pin-fin arrays. Micro-PIV results and simulation outcomes have been compared to investigate the flow and heat transfer characteristics of micro pin-fin arrays. Among three types of pin-fins, backflow occurs firstly at the tail of circular pin-fins and wake vortices form gradually, then the structure of the vortex gradually lengthens. The velocity and pressure transformation along the single pin-fin is a decompression acceleration region at first and turns into a pressurization deceleration from the middle to the tail of pin-fin. The area of higher temperature region of vortices at the back of circular pin-fin is the largest, which results in better heat transfer performance.