Séminaire de l'INPHYNI: Atul Varshney

Blood flow within the circulatory system is a complex and dynamic phenomenon essential for maintaining physiological functions. One fascinating aspect of blood flow is the occurrence of instabilities, deviations from smooth and laminar flow that can have significant implications for vascular health and disease. In this talk I will discuss the hydrodynamic (helical) instability that we have identified in pulsating pipe flow within cardiovascular settings, such as the aortic arch. We find that geometrical distortions of small, yet finite, amplitude excite a state consisting of helical vortices during flow deceleration. The resulting flow pattern grows rapidly in magnitude, breaks down into turbulence, and eventually returns to laminar when the flow accelerates.
I will also present our recent findings of a separate study, which indicate that if the flow of ordinary fluids is driven in a pulsatile mode that incorporates all the key features of the cardiac waveform, there is a significant reduction in turbulent friction.