Mixed convection Casson polymeric flow from a nonlinear stretching surface with radiative flux and non-Fourier thermal relaxation effects: Computation with CSNIS

Thermal non-Newtonian polymer coating flows is growing as a major area in materials processing. Inspired by new developments in this field which require more sophisticated mathematical models, the current investigation examines the laminar viscoplastic boundary layer flow and mixed convective heat transfer over a power-law nonlinear stretching surface. To simulate thermal relaxation effects the hyperbolic Cattaneo-Christov heat flux model is deployed. The non-Newtonian polymer characteristics are described by employing the Casson flow model. High temperature conditions invoke thermal radiation flux which is analyzed with an algebraic flux model. Via robust similarity transformations, the primitive partial differential conservation equations for momentum and energy equations are rendered into a system of coupled non-linear ordinary differential equations with associated wall and free stream boundary conditions. The emerging boundary value problem is solved numerically with an efficient Chebyshev Spectral Newton Iterative scheme (CSNIS), in the MATLAB platform. The resulting solutions are discussed for different emerging parameters using graphs and tables. Validation is included with special cases from the literature. With increasing power law stretching index increases, the flow is decelerated, and temperatures are reduced. Increment in mixed convection parameter boosts the velocity but suppresses temperature and thermal boundary layer thickness. Increasing non-Fourier Deborah number, temperatures are depleted whereas with increasing radiative flux parameter they are increased. With elevation in Casson non-Newtonian parameter, velocity is decreased whereas temperature is enhanced and Nusselt number is suppressed.

Automated summary

Thermal non-Newtonian polymer coating flows are increasingly important in materials processing. This study investigates the laminar viscoplastic boundary layer flow and mixed convective heat transfer over a power-law nonlinear stretching surface. Mathematical models, including the hyperbolic Cattaneo-Christov heat flux model and Casson flow model, are used to simulate thermal relaxation effects and describe the non-Newtonian polymer characteristics. The resulting system of coupled nonlinear ordinary differential equations is solved numerically using the Chebyshev Spectral Newton Iterative scheme.