Unsteady magnetohydrodynamic couple stress fluid flow from a shrinking porous sheet: Variational iteration method study

Reddy, G. Janardhana; Hiremath, Ashwini; Kumar, Mahesh; Beg, OA; Kadir, Ali

Abstract

AbstractMotivated by magnetic polymer manufacturing applications, the present research article examines theoretically the hydromagnetic boundary layer flow of an electrically conducting non‐Newtonian couple stress fluid due to a transient shrinking (contracting) porous sheet. The conservation partial differential equations for mass and momentum are rendered into a fifth‐order nonlinear ordinary differential equation via similarity transformations with associated boundary conditions. A semi‐analytical/numerical scheme employing Lagrangian multipliers and known as the variational iteration method (VIM) is implemented to solve the ordinary differential boundary value problem. Validation of the solutions is conducted by benchmarking against earlier Newtonian studies and very good agreement is achieved. A detailed assessment of the impact of couple stress (rheological), unsteadiness, magnetic body force parameter, and wall transpiration (suction/injection) parameter on flow characteristics is conducted with the aid of graphs. A significant deceleration in the flow is computed with increasing injection (acceleration is caused with greater suction) and acceleration is induced with higher unsteadiness parameter values. Increasing magnetic field (higher magnetic number) generates flow acceleration, rather than the customary deceleration, due to the shrinking sheet dynamics. A stronger couple stress effect manifests in strong retardation in the boundary layer flow and an increase in momentum (hydrodynamic|) boundary layer thickness. VIM demonstrates excellent convergence and accuracy and shows significant promise in studying further magnetic polymer fabrication flow problems.

Citation

Reddy, G. J., Hiremath, A., Kumar, M., Beg, O., & Kadir, A. (2022). Unsteady magnetohydrodynamic couple stress fluid flow from a shrinking porous sheet: Variational iteration method study. Heat Transfer, 51(2), 2219-2236. https://doi.org/10.1002/htj.22397

• Journal Article Type: Article
• Acceptance Date: Nov 5, 2021
• Online Publication Date: Nov 30, 2021
• Publication Date: Mar 1, 2022
• Deposit Date: Nov 26, 2021
• Publicly Available Date: Nov 30, 2022
• Journal: Heat Transfer
• Print ISSN: 2688-4534
• Electronic ISSN: 2688-4542
• Publisher: Wiley
• Volume: 51
• Issue: 2
• Pages: 2219-2236
• DOI: https://doi.org/10.1002/htj.22397
• Keywords: Fluid Flow and Transfer Processes, Condensed Matter Physics
• Publisher URL: https://doi.org/10.1002/htj.22397
• Related Public URLs: https://onlinelibrary.wiley.com/journal/26884542
• Additional Information: Access Information : This is the peer reviewed version of the following article: Reddy, GJ, Hiremath, A, Kumar, M, Bég, OA, Kadir, A. Unsteady magnetohydrodynamic couple stress fluid flow from a shrinking porous sheet: variational iteration method study. Heat Transfer. 2021; 1- 18., which has been published in final form at https://doi.org/10.1002/htj.22397. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.