When: Feb 21 2020 @ 4:00 PM
Where: 213 Hodson Hall
213 Hodson Hall

4:10 pm Presentation
“A Novel Modality for Continuous, Remote Monitoring of Transcatheter Heart Valves”
Presented by SHANTANU BAILOOR (Adviser: Prof. Mittal)
Transcatheter heart valves (THV) suffer from clinically silent complications which can result in fatal outcomes for the patient. This informs a critical need for continuous monitoring of THVs. We aim to conduct a data-driven, in-silico investigation into the viability of wireless, remote monitoring of prosthetic aortic valve health. To achieve this, we developed reduced-order valve models which are capable to simulating a wide range of valve conditions through simple changes to model parameters. High-fidelity simulations of transvalvular flow in the aorta, with supervised learning methods determine optimal sensor configuration. Preliminary results demonstrate pressure measurements at as few as two discrete locations per valve leaflet can accurately predict its status (“Healthy”/“Reduced mobility”) and quantify its range-of-motion.

4:35 pm Presentation
“DNS of Free-Stream Turbulence Interaction with Curved-Wall Boundary Layer”
Presented by JIHO YOU (Adviser: Prof. Zaki)
Direct numerical simulations (DNS) are performed to examine the effect of free-stream vortical forcing on a turbulent boundary layer over a concave wall. The homogeneous and isotropic free-stream forcing is introduced with intensity Tu = 10% at the inlet and becomes anisotropic on the curved section. Near the onset of the curvature, the skin friction suddenly decreases due to the adverse pressure gradient (APG). In this region, the flow exhibits the typical feature of decelerated boundary layers: decrease in the inner peak of streamwise stress and development of the outer bulge. As the pressure-gradient effect vanishes downstream along the curved surface, the enhancement of the wall-normal and spanwise stresses is more appreciable and the distance between their peaks increases, which is suggestive of the generation of Taylor-Görtler vortices. When the flow is forced by the free-stream turbulence (FST), the outer roll motions are much larger and thus the gap further increases. The coherent motions enhance the shear-stress correlation coefficient in the outer region of the forced flow than in absence of free-stream turbulence. The enlarged roll motions directly ingest FST into the boundary layer, towards the buffer layer on the curved section, which was not observed in the flat-plate study (You & Zaki, 2019), and the large-scale velocity structures strengthened by the curvature and FST more actively modulate the near-wall region.