Spectral Linearization and Statistical Analysis of 3D Darcy–Forchheimer Trihybrid Nanofluid Flow With Non‐Fourier Heat Flux and Entropy Optimization

Abstract

ABSTRACT Minimizing entropy generation and optimizing nanofluid performance are critical strategies for improving thermal management in advanced energy systems, including nuclear reactors, aerospace platforms, and automotive heat exchangers. This study examines the thermofluidic behavior of a Casson trihybrid nanofluid within an accelerating microchannel, focusing on entropy generation influenced by Darcy–Forchheimer drag effects and Cattaneo–Christove heat flux. The governing system of coupled nonlinear partial differential equations is transformed into a set of ordinary differential equations utilizing similarity transformations and solved numerically using the spectral local linearization method. Convergence and validation evaluate approve the accuracy and stability of the approach through comparison with established literature. Entropy generation is assessed with thermal conduction, viscous dissipation, and Joule heating as primary irreversibility mechanisms. Parametric investigations exhibit that the Brinkman number significantly improves the temperature distribution, while the Darcy–Forchheimer parameter reduces it due to increased flow resistance. The Reynolds number is shown to advance entropy generation, indicating greater thermodynamic irreversibility at higher velocities. Conversely, the Bejan number raises with both thermal radiation and Reynolds number, while declines under increased magnetic field strength and viscous dissipation effects. Furthermore, multiple linear regression and sensitivity analyses are employed to assess the influence of critical dimensionless parameters, posing statistical validation of the model's predictive capability. The findings emphasize the advanced thermophysical performance of trihybrid nanofluids and provide constructive insights into optimizing entropy generation and heat transfer characteristics in nanofluid‐based thermal systems under complex flow conditions.