Direct numerical simulation of flow in stenotic channel to understand the effect of stenotic morphology on turbulence

This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, redistribution , reselling , loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. A fundamental fluid dynamics study has been performed in order to understand the effect of shape of blockage in a stenotic channel on turbulence flow characteristics using direct numerical simulation (DNS) as a tool. DNS has been performed for four canonical types with identical degree of blockage (stenosis) but with varied morphological forms. The results revealed large-scale and small-scale features of the flow represented by the root mean square (rms) of velocity and vorticity statistics are type-dependent. The turbulent structures exhibited characteristic structures and mechanics very specific to the type of blockage. The analysis indicates that for given degree of stenosis, the turbulence characteristics are significantly dependent on the morphology of the blockage, and hence to quantify turbulence flow characteristics in stenosed channel, the stenosis shape is an important metric that needs to be considered. The results of this study are directly relevant to the flow dynamics in diseased stenotic coronary artery, in the context of the importance of stenotic morphology in addition to the height of the stenosis as an important indicator for the prediction of the flow dynamics in diseased coronary artery. 1. Introduction Turbulent flow in a stenosed channel has been studied as a fundamental fluid dynamics problem as well as in various applications of fluids in environmental and bio-engineering applications. In literature, the stenosed (obstructed/blocked) channel has been represented as the flow over rough wall in a channel/pipe. The underlying idea is that the geometrical obstruction (such as surface roughness) or blockage results in the modification of the flow dynamics, which is of great interest to fundamental fluid dynamician as well as to biomedical or environmental engineer for prediction of the flow properties/physics due to the obstruction/blockage. To understand the effects …