Computational Effects of Heat Transfer in Ostwald–de Waele Fluid with a Nonlinearly Stretching Cylinder

Abstract

This study explores the steady flow and heat transfer of an Ostwald–de Waele (power-law) fluid across a cylinder with nonlinear stretching, encompassing convective heating, nonlinear radiation, Joule heating, and a variable magnetic field. The governing boundary-value problem is worked out using MATLAB’s BVP4C collocation scheme and justified against existing literature. Three fluid types pseudoplastic, Newtonian, and dilatant fluids are observed to assess the influence of shear-dependent viscosity. The findings show that stretching nonlinearity plays a primary role in transport phenomena: nonlinear stretching (m = 2) consistently leads to higher skin-friction coefficients and larger Nusselt numbers than linear stretching, indicating strengthened near-wall gradients. Thermal responses depend on the controlling factor Ec, M, κ, ϕ, and R produce higher temperatures under linear stretching, whereas Pr reduces temperature more effectively under nonlinear stretching. Curvature enhances heat removal for all fluids, while magnetic damping suppresses heat transfer. These findings offer guidance for polymer extrusion and thermal processing of cylindrical materials.