Effect of Couple Stresses on Thermal Convection of Navier–Stokes–Voigt Fluid in Porous Media

This chapter examines the influence of couple stresses on thermal convection in a Navier–Stokes–Voigt (NSV) fluid layer within porous media, with a focus on industrial applications where non-Newtonian fluid characteristics are essential. By incorporating couple stresses into the NSV model, the analysis highlights viscoelastic and microstructural effects critical to applications such as polymer processing, bioengineering, and petroleum extraction, where fluid behavior significantly deviates from Newtonian assumptions. The study employs linear analysis using normal mode techniques and nonlinear analysis through the energy method to examine stability and convection onset. Additionally, energy decay analysis provides insight into stability predictions, offering parameters that influence convection dynamics. Findings from this investigation assist in optimizing the thermal management and performance of non-Newtonian fluid systems in heat exchangers, geotechnical processes, and enhanced oil recovery. Understanding how couple stresses alter flow and heat transfer in porous environments enhances modeling accuracy, ultimately supporting efficient engineering applications and improved operational outcomes.