# Nonlinear thermo-solutal convective flow of Casson fluid over an oscillating plate due to non-coaxial rotation with quadratic density fluctuation: Exact solutions

B. Mahanthesh (Department of Mathematics, CHRIST (Deemed to be University), Bengaluru, India)
T. Brizlyn (Department of Mathematics, CHRIST (Deemed to be University), Bengaluru, India)
SabirAli Shehzad (Department of Mathematics, COMSATS Institute of Information Technology, Islamabad, Pakistan)
Gireesha B.J. (Department of Mathematics, Kuvempu University, Shivamogga, India)

ISSN: 1573-6105

Article publication date: 14 June 2019

Issue publication date: 14 June 2019

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## Abstract

### Purpose

The nonlinear density thermal/solutal fluctuations in the buoyancy force term cannot be ignored when the temperature/concentration difference between the surface and fluid is large. The purpose of this paper is to investigate the nonlinear density fluctuations across a flowing fluid with heat mass transfer effects on a non-axial rotating plate. Therefore, the impact of nonlinear convection in the flow of Casson fluid over an oscillating plate has been analytically investigated.

### Design/methodology/approach

The governing equations are modeled with the help of conservation equations of velocity, energy and concentration under the transient-state situation. The dimensional governing equations are non-dimensionalized by utilizing non-dimensional variables. Later, the subsequent non-dimensional problem has been solved analytically using Laplace transform method.

### Findings

The effects of thermal Grashof number, solute Grashof number, nonlinear convection parameters, Casson fluid parameter, unsteady parameter, Prandtl number as well as Schmidt number on hydrodynamic, thermal and solute characteristics have been quantified. The numeric data for skin friction coefficient, Nusselt number and Sherwood number are presented. It is established the nonlinear convection aspect has a significant influence on heat and mass transport characteristics.

### Originality/value

The effect of nonlinear convection in the dynamics of Casson fluid past an oscillating plate which is rotating non-axially is investigated for the first time.

## Citation

Mahanthesh, B., Brizlyn, T., Shehzad, S. and B.J., G. (2019), "Nonlinear thermo-solutal convective flow of Casson fluid over an oscillating plate due to non-coaxial rotation with quadratic density fluctuation: Exact solutions", Multidiscipline Modeling in Materials and Structures, Vol. 15 No. 4, pp. 818-842. https://doi.org/10.1108/MMMS-06-2018-0124

## Publisher

:

Emerald Publishing Limited