Computational thermal performance analysis by LBM for cooling a hot oval object via magnetohydrodynamics non-Newtonian free convection by using magneto-ferrofluid

Abstract

The subject of equipment cooling has always been one of the most important issues that has imbibed the attention of many researchers. In addition to this matter, the system thermal performance analysis in which the cooling process takes place is very momentous. Cooling of an electronic component in a limited space is one of the cases of investigating these phenomena. Due to the importance of this issue, via LBM, the cooling of a hot body through the process of natural convection has been simulated. The cooling chamber is a tilted trapezoidal and contains a non-Newtonian ferrofluid, while the whole set, is under the effect of the magnetic field in different positions. By calculating the amount of entropy produced and the average Nusselt value under the impact of heat absorption, the best thermal performance was determined in this present work. Magnetic field strength (0⩽Ha⩽90), buoyancy forces strength (104⩽Ra⩽106), the fluid behavioral index (0.8⩽n⩽1.2), heat absorption coefficient (-20⩽Δ⩽0), the angle of chamber placement (0⩽ζ⩽270), the position of applying magnetic field (0⩽R⩽2H3) have been evaluated as the main variables. Based on the outcomes, for applying the magnetic field in the position of the middle third of the enclosure, the greatest effect of increasing the Hartmann value is observed. The highest thermal performance coefficient of the system can be obtained for the highest Rayleigh value, the lowest Hartmann value in the absence of heat absorption for the shear thinning fluid. By changing the angle of chamber placement, the system thermal performance can be effectively affected, so that the worst performance was reported at an angle of 270 degrees. For the highest value of heat absorption coefficient, the change in the values of the Hartmann number, power-law index and the Rayleigh number is not noticeable.