Forced convection Heat transfer enhancement and entropy generation of non-Newtonian CNT–water nano-fluid in a channel with a wavy bottom wall

Abstract

Numerical investigations have been conducted on the forced convection and entropy generation of a non-Newtonian Carbon Nanotube (CNT)-water nanofluid in a channel featuring a wavy bottom wall. The injected fluid is at a lower temperature than the horizontal walls. The governing equations are resolved using the finite volume method, which is founded on the SIMPLE algorithm. A diverse array of Reynolds numbers, corrugation numbers, power indices, wave amplitudes, and nanofluid volume fractions has been subjected to extensive numerical simulations. The influence of these characteristics on the local Nusselt numbers is analyzed. This study concludes that the incorporation of CNT nanoparticles and an increase in the number of corrugations can promote heat transfer in channels. The results indicate that heat transmission is markedly enhanced at low power-law indices. The local Nusselt number, indicative of heat transport, increases with the amplitude of undulations. Fluid velocity causes the local Nusselt number to rise when the Re number does. It was found that the heat transfer increases with decreasing power index due to the decrease in viscosity of the nanofluid and the local Nusselt number increases with increasing nanoparticle volume fraction. The results also showed that the entropy due to heat transfer and friction in corrugated channels is significantly affected by Reynolds number, power index, wave amplitude, corrugation number and nanoparticle volume fraction. By appropriate selection of these parameters, the heat transfer efficiency can be increased.

Keywords

• CNT nano-particles
• Non-newtonian
• Nanofluid
• Forced convection
• Wavy bottom wall