V R K Rao

Effect of hypotension in stenosed common carotid artery — A FSI study

Fluid-Structure Interaction (FSI) is one of the growing challenges in scientific computing wherein both fluid and structural solution domains are coupled using CFD and FEM methods respectively. Results from both the analysis are exchanged at interface junction in a synchronized manner to obtain an FSI solution. This study is helpful in observing the behavior of blood flow through arteries and to study the mechanisms of diseases like Atherosclerosis, Hypertension, Aneurysms etc. The blood flow distends the elastic artery due the flow-induced pressure and deformed artery in turn affects the flow behavior. In the present study, a simple straight common carotid artery having an eccentric blockage is analyzed under normal and low blood pressure conditions. The clinical data has been obtained from ultrasound measurements on a volunteer patient and modeling is done using ANSYS. An ANSYS Parametric Design Language (APDL) has been written in ANSYS to carry out the transient analysis and to obtain the arterial deformation, wall shear stress and velocity contour to observe the pulsatile flow. The obtained results reveal the significance of low blood pressure in comparison with normal pressure. The hypotension has less wall deformation as compared with normal case, reducing the flow rate in distal side. The results obtained agree very well with available clinical data.

Comparison of flow in normal and stenosed carotid bulb

Computational Fluid Dynamics (CFD) is one of the growing challenges in scientific computing wherein the complex fluid domains are analyzed. One such domain is blood flow analysis through elastic arteries. Such an analysis can be a promising future for the medical field where realistic physiological conditions can be simulated to observe the flow behavior. In the present study, a case study of normal and stenosed carotid bifurcation is simulated for a Newtonian case. The models are generated in CATIA based on the clinical data obtained from Ultrasound Doppler from a patient. A transient CFD analysis is performed for several pulse cycles for normal and stenosed models using ANSYS CFX to observe the changes in flow behavior at various sections of the model. The computed results agree well with clinical observations.