CFD Analysis on the Thermal Hydraulic Performance of an SAH Duct with Multi V-Shape Roughened Ribs

Anil Kumar,Man-Hoe Kim

doi:10.3390/en9060415

Abstract

This study presents the heat transfer and fluid flow characteristics in a rib-roughened SAH (solar air heater) channel. The artificial roughness of the rectangular channel was in the form of a thin circular wire in discrete multi V-pattern rib geometries. The effect of this geometry on heat transfer, fluid flow, and performance augmentation was investigated using the CFD (computational fluid dynamics). The roughness parameters were a relative discrete distance of 0.69, a relative rib height of 0.043, a relative rib pitch of 10, a relative rib width of 6.0, and a flow-attack-angle of 60°. The discrete width ratios and Reynolds numbers ranged from 0.5 to 2.0 and from 2000 to 20,000, respectively. The CFD results using the renormalization k-epsilon model were in good agreement with the empirical relationship. This model was used to investigate the heat transfer and fluid flow characteristics in the multi V-pattern rib roughened SAH channel. The thermo-hydraulic performance was found to be the best for the discrete width ratio of 1.0. A discrete multi V-pattern rib combined with dimple staggered ribs also had better overall thermal performance compared to other rib shapes.

Highlights

Solar energy is one of the most useful renewable energy resources without any adverse effects on the environment
This study presents Computational fluid dynamics (CFD) analysis on the thermal hydraulic characteristics of a three-dimensional
The topmost of the channel was considered as a hot heated heated plate with a constant constant heat heat flux flux channel

Summary

Introduction

Solar energy is one of the most useful renewable energy resources without any adverse effects on the environment. Solar energy is widely used for generating electricity, heating and various industrial applications. Solar air heaters (SAHs) are simple in design and generally used as solar thermal collectors [1]. SAHs form the foremost component of a solar energy utilization system [2]. These air heaters absorb the irradiance and exchange it into thermal energy at the absorbing surface and transfer this energy to a fluid flowing through the collector. SAHs are found in several solar energy applications, especially for space heating, timber seasoning and agriculture drying [3]

Results

Discussion

Conclusion