Hydromagnetic mixed convection in a triangular shed filled by nanofluid and equipped with rectangular heater and rotating cylinders

Abstract

Nanofluid mixed convection in a triangular shed equipped with rotating cylinders subjected to a heat source is numerically investigated in this study. The shed is heated and cooled respectively from a rectangular heat source at the bottom wall and inclined top walls. Two rotating cylinders are placed over the heat source. The shed is permeated by an external magnetic field. The conservation equations are solved using finite element method. The code is verified by comparisons with previously published results. The numerical results of flow and temperature fields are demonstrated via streamlines, isotherms and bar charts for the variation of key parameters: Reynolds number ( 0 ≤ Re ≤ 100 ), Hartmann number (0 ≤ Ha ≤ 50), nanoparticle volume fraction (0% ≤ φ ≤ 5%), rotational speed of cylinders (10 ≤ U c ≤ 100) and different positions of heat source. The strength of flow circulation is found accelerating with increasing Reynolds number and rotational velocity of cylinders but it declines for the effects of magnetic field and nanoparticle volume fraction. The thermal field is significantly influenced due to the variation in Reynolds number, cylinders rotational speed and the position of heat source. Maximum heat transfer is found at the corner positions of heat source, and it is 13.70% more than heat transfer for the case of centered position. Optimum heat transfer performance is taken place at higher rotational speed of the cylinders whereas reverse trend for higher magnetic strength. The best heat transfer rate is achieved in nanofluid with maximum concentration of nanoparticles (5%), which is 94.18% than heat transfer for base fluid water.