Utilising fractional porous interface for high thermal performance of serpentine wavy channel solar air heater

• Published in: Applied thermal engineering Vol. 205; p. 118044
• Main Author: Singh, Satyender
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 25.03.2022; Elsevier BV
• Subjects: Computational fluid dynamics; Configurations; Finite volume method; Fluid dynamics; Fluid flow; Heat transfer; Optimization; Porosity; Porous materials; Porous media; Reynolds number; Secondary flow; Serpentine; Serpentine wavy channel; Shape effects; Shape factor; Software; Solar air heater; Solar energy; Thermal performance, turbulence; Porous media; Serpentine wavy channel; Solar air heater; Thermal performance, turbulence
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2022.118044

•Thermal performance of a serpentine wavy channel solar air heater is investigated.•The effect of fraction of porous region and channel porosity is studied.•Results revealed the occurrence of secondary flow formation in the collector channel.•The fraction of porous region significantly affects the thermal performance.•The maximum thermohydraulic performance (THPP) of 4.5 is obtained. This work investigates the thermohydraulic performance of a porous serpentine wavy channel solar air heater. Comprehensive illustration on the effect of fractional porous interface (25%≤ξ≤100%), channel porosity (90%≤φ≤100%) and Reynolds number 2000≤Re≤11000 on the thermohydraulic performance of solar air heater design is presented. Experiments are performed and numerical results are validated to conduct further investigations for the optimization of the input variables. This study is a unique idea that broadly presents the scope of thermal performance improvement by utilizing the porous media in fraction and varying porosity in solar air heater channel and highly useful for the researchers of this field. Finite volume method based computational fluid dynamics tool is used to conduct numerical investigations, Forchheimer equation is used to account the effect of porous media and surface to surface (S2S) radiation model to capture the effect of shape factor and emitted radiation in collector channel. It is obtained that ξ of 25% and φ of 93% delineated the best thermohydraulic performance (THPP) of 4.52 for the present solar air heater design. While, the obtained thermohydraulic performance is 186% times higher compared to the smooth design. The excellent results that come into the light from numerical investigation are the secondary flow formation in the porous and flow zones at higher Reynolds number and lower fraction of porous region (ξ), and for all configurations of ξ at large channel porosity (φ). Hence, results of this investigation not only present the best operational configuration to obtain higher thermal performance, but also present the measures to reduce the material cost of porous media and consequently pumping power.