Computational analysis of bioconvective and melting heat transfer in thixotropic nanofluid flow over a porous stretching surface.

This study numerically investigates steady boundary-layer flow, melting heat transfer, and bioconvection in a thixotropic nanofluid over a porous stretching surface. The model incorporates a transverse magnetic field, Darcy porous resistance, thermal radiation, heat generation/absorption, and a first-order chemical reaction. Nanoparticle transport is described using Buongiorno's formulation through Brownian diffusion and thermophoresis, and cross-diffusion effects (Soret and Dufour) are included. Using similarity transformations, the governing partial differential equations are reduced to a coupled set of nonlinear ordinary differential equations, which are solved with MATLAB's bvp4c solver. The results show that magnetic and porous resistance suppresses the velocity field, while melting enhances near-wall motion. Thermophoresis increases the thermal boundary-layer thickness, whereas stronger melting reduces temperature. Higher Schmidt number and stronger chemical reaction decrease nanoparticle concentration and increasing the bioconvection Lewis number reduces microorganism density. The findings provide parametric guidance for controlling momentum, heat, mass, and microorganism transport in porous-surface coating and thermal processing applications.