Numerical simulation of heat transfer improvement of a new designed artificially roughened solar air heater using triangular ribs with semi-circular nooks

ABSTRACT

The present study represents a computational analysis of two-dimensional air flow in a new designed configuration of a solar air heater (SAH). The shape of the installed ribs along the absorber plate is a combination of triangular and semi-circular nooks with variable height of three ribs simultaneously. The objective is to optimize the Thermo-Hydraulic Efficiency Parameter (THEP) of the SAH by characterizing the values of roughness height (e) and pitch (P) of the considered ribs which provides the optimum patterns. Various (e) and (P) values for varied Reynolds number (Re) between 3,800 and 18,000 are investigated. An imposed constant heat flux is considered, and governing equations describing the flow and heat transfer are solved numerically with the selected RNG k-ε for the turbulence modeling. The obtained results indicate that the THEP strongly depends on the different investigated geometric parameters and Re number. The obtimum THEP value of 1.93 could be obtained for the case C1 and Re number of 5,000.

KEYWORDS:

• Solar air heater
• artificial roughness
• triangular semi-circular Ribs
• thermo-hydraulic efficiency
• improved heat transfer

Nomenclature

Table

Disclosure statement

No potential competing interest was reported by the authors.

Additional information

Notes on contributors

Boucif Zina

Boucif Zina is obtained his master’s degree in Mechanical and Power Engineering option Mechanical Engineering from Center University of Ain Temouchent in 2016. He is currently a Ph.D student in the Mechanical Engineering Department with a specialization in Energetics at the University of Djillali Liabes, Sidi Bel Abbes, Algeria. His research interests on numerical simulation of solar air heaters.

Abdelkader Filali

Abdelkader Filali is currently an Assistant Professor at National Polytechnic School of Constantine, ENPC, Algeria. He is also a Visiting Research Association in the Chemical Engineering department at Imperial College London, UK since Mars 2018. He obtained his B.Eng. M.Sc. and Ph.D. in Mechanical Engineering (1st class honours) from University Constantine 1, Algeria.  He completed his Ph.D. during his scholarship as an Assistant researcher at the Petroleum Institute Abu Dhabi, UAE during the period 2010-2014.  His main research interest is in the area of Computational Fluid Dynamic (CFD), Rheology, Multiphase flows and Renewable energy. He is a member of APS American Physical Society since September 17, 2019, a member of the UNISCO IGCP Project - The International Geoscience Programme – Since Mars 2020.

Nabil Benamara

Nabil Benamara is teacher and researcher at the Djillali Liabes university of Sidi Bel-Abbes, Algeria and team leader in the materials and reactive systems laboratory. Research area revolves around simulation and numerical modeling, flow and thermal transfer, renewable energy.

Samir Laouedj

Samir Laouedj is lecturer/Researcher at the Department of Mechanical Engineering at the University of Djillali Liabes, Sidi Bel Abbès, Algeria. His main research interest is in the area of Fluid Mechanics, Modeling Heat Transfer, Heat Exchangers and solar air heaters.

Hamdi Ahmed

Hamdi E. Ahmed was graduated from College of Engineering, University of Anbar, Iraq, in 2002. He has got a master’s degree in Mechanical Engineering from University of Anbar in 2005. He has also a Ph.D. in Mechanical Engineering, Universiti Tenaga Nasiontal, Malaysia, in 2014. He is interested in CFD, Nanofluids, optimal hydrothermal design of heat exchangers using turbulators, and using porous media for heat transfer enhancement.