Numerical simulations of flow pattern and particle trajectories in feline aorta for hypertrophic cardiomyopathy heart conditions

• Published in: Engineering applications of computational fluid mechanics Vol. 12; no. 1; pp. 57 - 73
• Main Authors: Borse, M., Bhushan, S., Walters, D. K., Burgreen, G. W.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01-01-2018; Taylor & Francis Group
• Subjects: computational fluid dynamics (CFD); feline aorta; Hypertrophic cardiomyopathy (HCM); particle transport; turbulence modeling
• ISSN: 1994-2060; 1997-003X
• DOI: 10.1080/19942060.2017.1339640

Numerical simulations of pulsatile flow in a feline aorta for hypertrophic cardiomyopathy (HCM) heart conditions are performed to predict flow details and to evaluate possible thrombus trajectory patterns. The study demonstrates that average flow rate boundary conditions (Q
BC
) at artery outlets act as a resistance-type boundary condition for pulsatile flow. For simulations when the exact artery outflows are not known, specification of estimated values from physiological conditions is a plausible approach. This boundary condition is further improved using an iterative method (I-Q
BC
) to accurately satisfy outflow conditions when expected outflow is known. The approach is validated against experimental data for the prediction of iliac artery flow and wall stresses in a human abdominal aorta. The feline aorta simulations including Lagrangian particle transport are performed on grids with up to 11M cells for a generalized feline aorta. It is found that LES on larger grids performs significantly better than URANS for the prediction of vortical structures. Simulations for both healthy and HCM conditions show similar flow patterns in the upper abdominal aorta. However, the HCM condition shows the presence of large recirculation regions in the thoracic aorta resulting in 50% lower flow through the iliac arteries and increased entrapment of fluid-borne particles near the trifurcation region compared to the healthy condition.