Intracranial aneurysms (IAs) are abnormalities formed in the cerebral arteries characterized by outpouching regions of their walls. The danger with these lesions occurs if they rupture, which causes intracranial hemorrhage and possibly leads to the death of the patient, presenting a mortality rate as high as 50 %. The rupture event is hard to predict, though, and surgical treatments also pose risks to patients. Numerical simulations of the blood flow inside IAs have been extensively used to study them because of the well-known connections between hemodynamics and their inception, growth, and rupture, with the wall shear stress on the arterial lumen being one of the main factors responsible for this evolution. However, when using numerical simulations to solve this problem, adequate models of the flow are important and one of the most used assumptions is the of laminar regime, due to the low values of the Reynolds number in this type of flow. Some works indicate that transition to turbulence may occur inside the aneurysms due to the transient nature of the flow. In this context, it is important to verify which turbulence models could be used to more accurately predict the wall shear stress in cases where transition occurs. This is the main goal of this project. Numerical simulations with real vascular geometries will be performed using Computational Fluid Dynamics with different turbulence models in the OpenFOAM® software. The wall shear stress, as well as other hemodynamic parameters related to it, will be compared between the different models employed and validated with results from direct numerical simulations of turbulence. The results may lead to a better modeling of the flow in intracranial aneurysms and, thus, may help in guiding their management.
News published in Agência FAPESP Newsletter about the scholarship: