An Experimental and Computational Study on the Compliance of Coronary Artery,Considering Non-Newtonian Blood Flow

In account of the importance of mortalities due to stenosed arteries, flow through atherosclerotic arteries is of great interest. Moreover, the correlation between stiffening of arteries induced by aging and hypertension necessitates biomechanical evaluation of arterial function. Arterial wall shear stress is an important hemodynamic parameter, determining distribution of atherosclerosis. Moreover, arterial compliance is another parameter defining onsets of atheroma and endothelial injury. In this study we utilize an experimental setup to investigate effects of wall compliance on wall shear stress (WSS) pattern. The experimental setup comprise of three major parts: a pump with pulsetile flow for simulating coronary flow, an elastic tube as a model of coronary artery with similar mechanical and geometrical properties, and a processor for acquisition and processing experimental data. The blood assumed as a non-Newtonian fluid. To investigate the effects of elasticity, the elastic modulus of wall have been changed and its influence on wall shear stress was studied through numerical FSI modeling. The governing equations of the flow are Navier–Stokes equations with dynamic equilibrium equations of solid wall. Arbitrary Lagrangian–Eulerian (ALE) formulation is used for imposing interaction between blood flow and arterial wall. The coupled fluid and structure models were solved by numerical software ADINA (v8.5, ADINA). The resultant parameters include pressure pulse and shear stress. Results indicated that increased compliance of wall lead to decrease in wall shear stress and decline of vortex formation.

کلیدواژه ها:

Fluid-Structure Interaction (FSI) ، Elastic arterial wall ، Wall Shear Stress (WSS) ، pressure pulse ، Non-Newtonian blood flow