Blood Flow

Simulations of Physiological flows have a huge significance in medical field (especially in the domain of diagnosis and surgery planning). Abnormalities in arteries which lead to cardiovascular issues are a major cause for mortality around the world. Diagnosis at early stage and surgical intervention can help to avoid sudden deaths. These interventions can be made more successful if the aftermath is known before the procedure. Computational simulation of blood flow inside artery plays crucial role in these situations. 

Blood flow simulation through coronary arteries presents a very complex hemodynamics problem especially in relation to the understanding of atherogenesis. This work was dedicated towards the study of hemodynamic parameters in tortuous left coronary artery (LCA) with 50 percent stenosis at the circular bend. The variation of wall shear stress (WSS), oscillatory shear index (OSI) and haematocrit distributions with tortuosity parameters like radius of curvature of artery, bend angle and Womersley number were studied by taking into account the Non-Newtonian rheology of blood and diffusive flux using the Philip’s shear-induced diffusion model. The numerical method was validated and it exhibited good consistency with the available experimental results for channel flow. The main objective of this work was to understand the effect of tortuosity on the probability of formation of atherosclerosis. Laminar flow was considered and the artery walls were assumed to be rigid. The percentage increase in OSI with the Womersley number was found to be more than the corresponding increase with Dean number. But there was a sharp increase in OSI for bend angle of 120 and Dean number of 261 and 369. The peak WSS also increased with tortuosity indices but was found to be almost constant with Womersley number. The results shows that hemodynamic parameters, hematocrit distribution and velocity distributions are significantly affected by various geometries of tortuous artery.

Details of the Project:

Timeline : December 2017 to May 2018

Supervisor : Dr. Arun Mahalingam, Associate Professor, Department of Mechanical Engineering, National Institute of Technology, Karnataka.

Figure : Variation of Maximum wall shear stress at different bend angle and Deannumber at Womersley Number of 2.5.