Chemically Driven Convective Instabilities in Binary Nanofluids with Thermodiffusions

Abstract

An investigation of the onset of chemically driven convective instabilities in binary nanofluids has been carried out under the influence of thermodiffusion and nanoparticles. In order to investigate the convective instabilities, the Tiwari-Das nanofluid model is used and the thermal Rayleigh number is derived using linear stability analysis. The effect of nondimensional parameters involved in the study is illustrated graphically. It is found that volume fraction of nanoparticles, Soret effects of nanoparticles and solute destabilize the system and Lewis number stabilizes the system. The heat of chemical reaction parameter performs a dual consequence on the stability. It has stabilizing effect for its negative values and destabilizing effect for its non-negative values. The strength of chemical reaction is also discussed. It is reported that the chemical reaction is fast when the system is heated from below and it is slow when the system is heated from above. Water-ethylene glycol based silver and cupric oxide pseudoplastic non-Newtonian binary nanofluids are considered and the impact of nanoparticles is analyzed through addition factors. The binary nanofluids convection driven by chemical reaction has a great importance in absorption based industrial applications such as refrigeration, air conditioning, automobiles, biomedical engineering, solar collectors and falling film.