Int. J. Renew. Energy Dev. 2023, 12(1),155-165 | 155 https://doi.org/10.14710/ijred.2023.46838 ISSN: 2252-4940/© 2023.The Author(s). Published by CBIORE Contents list available at IJRED website International Journal of Renewable Energy Development Journal homepage: https://ijred.undip.ac.id Numerical Analysis of Transfer of Heat by Forced Convection in a Wavy Channel Naseer Abboodi Madlool a , Mohammed J. Alshukri a , Ammar I. Alsabery b,* , Adel A. Eidan c , Ishak Hashim d a Department of Mechanical Engineering, Faculty of Engineering, Kufa University, 54002, Najaf, Iraq b Refrigeration & Air-conditioning Technical Engineering Department, College of Technical Engineering, The Islamic University, Najaf, Iraq c Najaf Technical College, Al-Furat Al-Awsat Technical University, 540011, Najaf, Iraq d Department of Mathematical Sciences, Faculty of Science & Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia Abstract. Convective heat transfer of laminar forced convection in a wavy channel is studied in this paper. Numerical simulations of the 3D steady flow of Newtonian fluid and heat transfer characteristics are obtained by the finite element method. The effects of the Reynolds number (10 ≤ Re ≤ 1000), number of oscillations (0 ≤ N ≤ 5) and amplitude of the wall (0.05 ≤ A ≤ 0.2) on the heat transfer have been analyzed. The results show that the average Nusselt number is elevated as the Reynolds number is raised, showing high intensity of heat transfer, as a result of the intensified effects of the inertial and zones of recirculation close to the hot wavy wall. The rate of heat transfer increases about 0.28% with the rise of the number of oscillations. In the transfer of heat along a wavy surface, the number of oscillations and the wave amplitude are important factors. With an increment in the number of oscillations, the maximal value of the average velocity is elevated, and its minimal value occurs when the channel walls are straight. The impact of the wall amplitude on the average Nusselt number and dimensionless temperature tends to be stronger compared to the impact of the number of oscillations. An increase of the wall amplitude improves the rate of heat transfer about 0.91% when the Reynolds number is equal 100. In addition, when the Reynolds number is equal 500, the rate of heat transfer grows about 1.1% with the rising of the wall amplitude. Keywords: Forced convection; Finite difference method; Heat transfer; Wavy channel; 3D simulation @ The author(s). Published by CBIORE. This is an open access article under the CC BY-SA license (http://creativecommons.org/licenses/by-sa/4.0/). Received: 13 th July 2022; Revised: 28 th Sept 2022; Accepted: 5 th Nov 2022; Available online: 20 th Nov 2022 1. Introduction A strategy that is usually employed to improve the transfer of heat by convection in a channel is the application of wavy walls. The undulation disturbs the hydrodynamics as well as the thermal boundary layers, forming a recirculation zone between the undulations. The point of reattachment leads to washing of the channel wall, thereby raising the transfer of heat by convection. A number of studies have investigated how fluid and heat flow in a channel with wavy walls (cf. Alsabery et al. 2022; Alshukri et al. 2018; Bourouis and Prévost 1994; Izumi et al. 1983; Leontini et al. 2007; Nishimura et al, 1993; Rush et al. 1999; Sheikholeslami et al., 2022; Wang and Vanka 1995). The advance of computational technologies in recent years has made numerical simulation an important tool to generate results of great contribution to the engineering field, mainly in fluid mechanics and heat transfer problems (cf. Abu Talib and Hilo 2021; Eidan et al. 2021; Errico and Stalio 2014; Feijó et al. 2018; Jabbar, Alshukri, and Madlool 2018; Li et al. 2022; Miroshnichenko et al. 2017). Errico and Stalio (2014) considered a direct numerical simulation of turbulent forced convection in a wavy channel at low and order-one values of the Prandtl number (Hajialibabaei and Saghir 2022). The numerical * Corresponding author Email: ammar_e_2011@yahoo.com (A.I. Alsabery) simulation costs make this technique very attractive compared to the cost of high-quality experimental equipment and installations, particularly for geometrical optimization, where several different configurations need to be investigated (Adhikari et al. 2020). Computational techniques to complement experimental results have also proved a viable alternative to obtain reliable recommendations about design in thermal devices. Concerning specifically the investigation of corrugated or finned channels and design in channels subjected to convection heat transfer, several interesting studies have been reported. For example, Nishimura et al. 1989 studied convective flows in symmetric wavy-walled channels. Later, Vasudeviah and Balamurugan (2001) studied forced convective Stokes flows in a wavy channel. Afterwards, Kim et al. (2013) investigated the influence of different cross-sectional shapes of a printed circuit heat exchanger (PCHE) on thermal performance and pressure drop. Their results indicated that semi-circular channels gave the best performance in the multi-objective analysis. Recently, Jing et al. (2020) studied the hydraulic and thermal performances of laminar flow in a fractal treelike branching microchannel network with wall velocity slip. Lyu et al. (2020) studied the flow of fluid and transfer of heat in a microchannel Research Article