Thermal analysis of magnetized [formula omitted] nanolubricant flow in a Darcy-Forchheimer porous medium with nonlinear heat generation

Abstract

The nanolubricant ZnO−SAE50 is widely used in automobiles and heat exchange systems to minimize friction and resist corrosion and scrape between moving parts. It also improves system's performance and durability and cuts fuel consumption. In this work, the flow of magnetized ZnO−SAE50 nanolubricant is analyzed over a flat plate with variable temperature immersed in a Darcy-Forchheimer medium. The thermal analysis is carried out in the occurrence of nonlinear heat generation and thermal radiation. Furthermore, the influences of viscous dissipation and Joule heating have also been deliberated. A micro-nano convection model named as Patel model of thermal conductivity has been used in view of rise in thermal conductivity. The governing PDEs are altered to ODEs with the incorporation of similarity transformations and then numerically treated by using an eminent MATLAB's built-in bvp4c method. The influences of different physical parameters on velocity, temperature and Nusselt number are discussed and analyzed graphically and in tabular form. The velocity profile diminishes under the impacts of inertia coefficient and magnetic field. The temperature and exponential dependent heat generation parameters considerably enhance temperature of the nanolubricant ZnO−SAE50. The temperature power coefficient tends to reduce the temperature profile. The enhancing strength of thermal radiations and nonlinear heat generation significantly enhance the value of Nusselt number. Furthermore, an increase in the value of temperature dependent heat generation parameter from 0.2 to 0.6 tends 12.37% increment in the value of Nusselt number in conventional SAE50oil, whereas the nanolubricant ZnO−SAE50 experiences a more significant 26.72% increment in the value of Nusselt number. Thus, better heat transmission rate can be achieved by using ZnO−SAE50 nanolubricant rather than conventional SAE50 oil.