Immersed boundary simulation of flow through arterial junctions

摘要

The present work demonstrates implementation of a mass-conserving sharp-interface immersed boundary for simulation of flows in branched arterial geometries. A simplistic two-dimensional arterial junction is considered to capture the preliminary flow physics in the aortic regions. Numerical solutions are benchmarked against established available experimental PIV results in Ensley et al (Annu. Thorac. Surg. 68(4):1384–1390,1999) and numerical predictions in Gilmanov and Sotiropoulos (J. Comput. Phys. 207(2):457–492, 2005) and deZelicourt et al (Comput. Fluids 38(9):1749–1762, 2009). Simulations are further carried out for pulsated flows and effects of blockages near the junctions (due to stenosis or atherosclerosis). Instabilities in the flow structures near the junction and the resulting changes in the downstream pulsation frequency were observed. These changes account for the physiological heart defects that arise from the poorly working valve (due to blockage),giving rise to chest pain and breathing instability, and can potentially be used as a detection tool for arterial diseases.