Finite element analysis of conjugate heat transfer and non-Newtonian blood flow in a stenosed bifurcated artery

Abstract

In the present study, a detailed numerical analysis is conducted for conjugated heat transfer in non-Newtonian blood flow in a stenosed bifurcated artery. The purpose of the present study is to investigate the coupling mechanisms between the arterial geometry, flow behavior and heat transfer under physiologically meaningful situation. The blood is simulated as power-law fluid to portray the non-Newtonian flow characteristic and the stenosed region is treated as solid region with conductivity to analyze the conjugated heat transfer effect. Nonlinear momentum and energy equations are solved using FEM. The effect of different parameter, such as Re (100-500), stenosis level and n are analyzed. Results show that an increasing stenosis severity makes the flow separation stronger and a greater pressure drop is gained and the local Nusselt number drops to 18.4%, which represents degradation of the convection heat transfer. For a rise in Re the thermal transport gets increased, which results the improvement of average Nusselt number by approximately 27% due to larger inertial effect. Shearthinning fluid n < 1 produces higher gradient of velocity, which increase the heat transfer performance; inversely, the increasing resistance of the shear-thickening fluid (n > 1) results in lower heat transfer performance. It can be inferred from the analysis of the present study that flow separation, artery morphology and fluid rheology play an important role in convective heat transfer; this analysis can be employed in design of artificial vascular graft and blood thermal therapies etc. In future, studies involving pulsatile flow, fluid-structure interaction and the dependence of viscosity on temperature need to be performed to have more physical relevance.