Thermal Hydraulic Performance in a Solar Air Heater Channel with Multi V-Type Perforated Baffles

Anil Kumar,Man-Hoe Kim

doi:10.3390/en9070564

Abstract

This article presents heat transfer and fluid flow characteristics in a solar air heater (SAH) channel with multi V-type perforated baffles. The flow passage has an aspect ratio of 10. The relative baffle height, relative pitch, relative baffle hole position, flow attack angle, and baffle open area ratio are 0.6, 8.0, 0.42, 60°, and 12%, respectively. The Reynolds numbers considered in the study was in the range of 3000–10,000. The re-normalization group (RNG) k-ε turbulence model has been used for numerical analysis, and the optimum relative baffle width has been investigated considering relative baffle widths of 1.0–7.0.The numerical results are in good agreement with the experimental data for the range considered in the study. Multi V-type perforated baffles are shown to have better thermal performance as compared to other baffle shapes in a rectangular passage. The overall thermal hydraulic performance shows the maximum value at the relative baffle width of 5.0.

Highlights

Solar energy is one of the renewable and environment-friendly energy sources which can be used in our daily lives without imposing negative effects on the environment
The Computational fluid dynamics (CFD) analysis has been performed for a roughened rectangular channel with multi V-down perforated baffles on a heated plate, and the results are discussed
The heat transfer and pressure drop characteristics have been investigated in multi V-pattern perforated baffle attached on one broad wall, which is exposed to uniform heat flux in a rectangular

Summary

Introduction

Solar energy is one of the renewable and environment-friendly energy sources which can be used in our daily lives without imposing negative effects on the environment It is generally used for a variety of engineering applications, among the generation of electric power, heating, cooking, and other applications. The use of baffles roughness on the underside of the heated wall can substantially enhance the local heat transfer of the SAH due to the rise in convective heat transfer rate from the plate to air. V-baffles allows the release of theinsecondary and the mixing with theperforated main stream through the perforations, as shown. The maximum value of the f ave has been observed at a value of Wc/Wb of 7.0 This is due to fact that angulation of the baffles helps in the development of the secondary stream jets. Increasing the value of Wc/Wb would lead to an increased number of secondary stream jets, which in turn increases the value of the

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