LAUSR

Abstract In a certain size micro thermofluid systems, the temperature of the cooling fluid at the vicinity of the solid hot wall differs from the temperature of the wall. This temperature difference can be modelled by using a temperature jump parameter, which relates the temperatures of the fluid and solid at the interface, and the gradient of the temperature in the solid wall. In this investigation, two micro porous channels with asymmetric thick walls have been considered; one with constant, but different, temperature boundary conditions and the other one with heat flux and convection boundary conditions at each of the walls, in order to determine the impact of the interface entropy generation rates on the total entropy generation calculation, particularly when the solid-fluid interface temperature jump has been assumed in a micro channel. The effects of the magnetic field have been addressed in both the momentum and energy equations of the porous section of the system. The slip velocity and temperature jump interface boundary conditions for both the upper and lower fluid-wall interfaces are considered. The results indicate that when the temperature jump parameter is weak, the interfaces entropy generation rates may be neglected in the calculation of the total entropy generation rate. However, if the temperature jump parameter is strong enough, the total entropy generation rate should be calculated by considering the interfaces entropy generation rate. It is interesting to note that depending on the micro porous channel outer boundary conditions, the total entropy generation rate may increase or decrease in accordance with the temperature jump parameter.