Impact of needle size and distinct flow conditions on thermal performance of TiO2–MWCNTs hybrid nanofluid flow past thin needle using Casson fluid model

Abstract

AbstractHybrid nanofluids comprising carbon nanotubes (CNTs) are finding applications in advanced heat exchange technologies due to the unusually high thermal conductivity and chemically inert nature of CNTs. The thermal performance of a hybrid nanofluid, comprising MWCNTs and TiO2 nanoparticles and flowing past a thin hot needle, is investigated in the present article. The Sakiadis and Blasius hybrid nanofluid flow scenarios around a parabolically shaped thin hot needle are modeled by using a non‐Newtonian Casson fluid model coupled with the energy equation. The governing equations are coupled non‐linear partial differential equations which are solved by the shooting method along with the 4th order Runge–Kutta method. The main aim of the study is to perform a comparative analysis among the base fluid (which is a 50:50 mixture of ethylene glycol [EG] and water), TiO2/EG–water nanofluid, and TiO2–MWCNTs/EG–water hybrid nanofluid and to analyze which fluid is the best transporter of heat. Apart from this, the impact of needle size and different flow conditions on heat transport is investigated. The numerical results reveal that the rate of heat transfer is maximum for TiO2–MWCNTs/EG–water hybrid nanofluid among the base fluid, nanofluid, and hybrid nanofluid. The magnitude of the Nusselt number is high for the case of the Blasius flow than for the Sakiadis flow.