Unveiling the effect of working fluid thixotropy on fluid flow and heat transfer characteristics in superhydrophobic micro-grooved channels

Thixotropic non-Newtonian fluids are widely used in medicine, coatings, and electronic cooling. This study investigates the fluid dynamics and heat transfer behavior of a thixotropic fluid in a superhydrophobic grooved microchannel using the Moore model. The influence of structure build-up rate (a), structure breakdown parameter (b), thixotropic index (α), wall temperature (Tw), domain temperature (Tp), and Reynolds number (Re) on pressure drop and thermal performance is evaluated. Each parameter is varied individually, while others are held constant. Varying a (0.01–100) shows minimal impact on early-time viscosity and no effect at steady state. Parameter b has a more noticeable influence on inlet viscosity but, like a, does not alter steady-state thermo-fluid properties. For α (1–10), higher values reduce asymptotic viscosity due to higher shear rates, lowering the pressure drop without significantly changing shear or vorticity. Wall temperature (303–323 K) has negligible early-time effects but, at steady state, higher temperatures reduce near-wall viscosity and pressure drop. For Re (140–879), higher shear stress accelerates the transition to asymptotic viscosity. At steady state, axial convection dominates, narrowing the low-viscosity region near the wall. Increasing domain temperature (293–313 K) further reduces viscosity at steady state. Overall, thixotropy significantly enhances pressure drop performance without compromising heat transfer, highlighting the fluid's potential for efficient thermal management in microscale systems.