Transport pattern of Non-Newtonian mass and thermal energy under two diverse flow conditions by using modified models for thermodynamics properties

Abstract

Background and purpose: The viscosity and thermal conductivity play an important role in transport of mass and thermal energy. The effect of temperature on these properties could not be ignored during fluid flow because flow pattern determines the performance and economic situation of the overall process. In view of these facts, the models of these properties are modified to measure the temperature effects and used in the transport equations of non-Newtonian fluid. Design of model: The mathematical model is based on continuity, momentum and energy equations. The model is simplified by applying the boundary layer and similarity transformations and then solved by numerical method. The influence of affected properties is examined on the velocity and temperature profiles as well as on the Skin friction coefficient and Nusselt number under two flow conditions: a) when mainstream fluid moves faster than surface motion and b) vice versa. Findings: In the results, the viscosity and thermal conductivity are reduced with increasing of temperature which became the cause of enhancement in velocity profile and reduction in temperature profile. Moreover, Nusselt number is increased with average rate 2.8% and 0.45% respectively under both conditions when viscosity is reduced by temperature.

Keywords

• Transport of mass and heat
• Non-Newtonian fluid
• Modified viscosity and thermal conductivity models
• Flow under two different conditions