EFFECTS OF ROTATIONAL MODULATION ON CONVECTION IN ETHYLENE GLYCOL-BASED HYBRID NANOFLUIDS WITH INTERNAL HEATING

Abstract

The rotational modulation effects on Rayleigh-Bénard convection in ethylene glycol-based hybrid nanofluids with internal heating are investigated. Due to their improved thermophysical properties as compared to base fluid, nanofluids are frequently used in numerous heat transfer applications. Hybrid nanofluids with suitable nanoparticle combinations can have better thermophysical characteristics than mono nanofluids. As a result, this study investigates the impact of hybridizing the base fluid on system stability and heat transfer. A single-phase model is employed to perform a linear and weakly nonlinear stability analysis of the nanofluid. The nonautonomous Ginzburg-Landau equation is derived and solved, and the solution is used to obtain the Nusselt number expression. Based on the linear analysis, the critical Rayleigh number attained in the case of hybrid nanofluids is less than the value found in the case of mono nanofluids. Therefore, the convection onset is faster in a hybrid nanofluid than in a mono nanofluid. The study further shows that hybrid nanofluid ethylene glycol-alumina-copper increases the heat transportation rate as compared to the mono nanofluid ethylene glycol-alumina, presenting evidence that hybrid nanofluid facilitates heat transfer better than the mono nanofluid. Increasing the volume of hybrid nanoparticles qualitatively improved heat transfer by up to 5.96%. Further, the effects of important fluid parameters on heat transfer are presented. Among other results, we found that increasing the modulation's amplitude improves heat transmission in the hybrid nanofluid.