A computational study on the generation of the Coanda effect in a mock heart chamber (Mathematical Analysis of Viscous Incompressible Fluid)

Abstract

We present a numerical study of laminar incompressible flows in two-dimensional and three-dimensional contraction-expansion channels. The aim is to understand the causes of the so-called Coanda effect (i.e., the tendency of a fluid jet to be attracted to a surface) in order to reproduce wall-hugging jets in a mock heart chamber constructed to improve the diagnosis of mitral valve regurgitation. First, we validate the critical Reynolds number for the onset of the Coanda effect (also known as symmetry-Ureaking bifurcation) given by our computations against the values found in the literature. Excellent agreement is found. Then, we considered flow in a section of the mock heart chamber and showed how a pronounced Coanda effect is possible only with some modifications of the contraction channel geometry. Finally, we propose a 3mathrm{D} mock heart chamber in which quasi-2D flow is possible, thereby allowing the Coanda effect at the low Reynolds numbers for which it is observed in 2mathrm{D}.