Title: Numerical solution and Taguchi experimental method for variable viscosity and non-Newtonian fluids effects on heat and mass transfer by natural convection in porous media

Authors: Ken Ming Tu; Kuo Ann Yih; Fu I. Chou; Jyh Horng Chou

Addresses: Department of Electrical Engineering, National Kaohsiung University of Science and Technology, No. 415, Jiangong Rd., Sanmin Dist., Kaohsiung City 8077, Taiwan; Department of Aircraft Engineering, Air Force Institute of Technology, No. 1, Julun Rd., Gangshan Dist., Kaohsiung City 82063, Taiwan ' Department of Aircraft Engineering, Air Force Institute of Technology, No. 1, Julun Rd., Gangshan Dist., Kaohsiung City 82063, Taiwan ' Department of Automation Engineering, National Formosa University, No. 64, Wunhua Rd., Huwei Township, Yunlin County 632, Taiwan ' Department of Mechanical Engineering, National Chung Hsing University, No. 145, Xingda Rd., South Dist., Taichung City 402, Taiwan; Department of Electrical Engineering, National Kaohsiung University of Science and Technology, No. 415, Jiangong Rd., Sanmin Dist., Kaohsiung City 8077, Taiwan; Department of Healthcare Administration and Medical Informatics, Kaohsiung Medical University, No. 100, Shih-Chuan 1st Road., Kaohsiung 807, Taiwan

Abstract: In this article, both numerical solution and Taguchi method are presented to study the variable viscosity and non-Newtonian fluids effects on coupled heat and mass transfer by free convection over a vertical permeable plate in porous media. The surface temperature, concentration of the plate, and blowing/suction velocity are uniform. The viscosity of the fluid varies inversely as a linear function of the temperature. The partial differential equations are transformed into non-similar equations and solved by Keller box method. Numerical results of the local Nusselt number and local Sherwood number are expressed in the five parameters: 1) blowing/suction parameter ξ; 2) the power-law index of non-Newtonian fluid n; 3) buoyancy ratio N; 4) Lewis number Le; 5) viscosity-variation parameter θr. The best value for confirming the maximum of the local Nusselt (Sherwood) number by the Taguchi method is 6.6328 (10.3056).

Keywords: Taguchi experimental method; variable viscosity; non-Newtonian fluid; free convection; vertical permeable plate; porous media.

DOI: 10.1504/IJCSE.2020.107347

International Journal of Computational Science and Engineering, 2020 Vol.22 No.2/3, pp.252 - 261

Received: 17 Sep 2018
Accepted: 25 Jul 2019
Published online: 18 May 2020 *

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