Single-Phase Blood Flow in a Stenosed Coronary Artery: A Clinical Model-Based Experimental and Numerical Study

Abstract

This study aims to develop an experimental platform that emulates the human cardiovascular system to investigate the effects of varying pulse rates and fluid properties on pressure drop, peristaltic pump output pressure, and power consumption. To support the experimental findings, computational fluid dynamics (CFD) simulations were conducted to analyze single-phase blood flow dynamics. Idealized arterial geometries representing healthy (0% stenosis) and diseased (65% stenosis) conditions were reconstructed from computed tomography (CT) images. A non-Newtonian blood-mimicking fluid (XSCN) was formulated to better replicate the rheological behavior of blood, while distilled water was used as the Newtonian reference fluid. Experiments were conducted at six different pulse rates: 72, 84, 96, 114, 132, and 156 beats per minute (bpm). The experimental setup was replicated in a virtual environment using ANSYS Fluent to simulate flow behavior under identical boundary conditions. The results demonstrate that increasing pulse rate leads to an increase in pressure drop (ΔP), pump output pressure, and power consumption for both arterial models. These effects were more pronounced in the stenosed artery due to flow constriction. Elevated turbulence intensity was observed at higher pulse rates, with notable differences between Newtonian and non-Newtonian fluids, particularly in terms of flow resistance and shear-dependent viscosity. Power consumption was found to be directly correlated with fluid viscosity, which varied with shear rate in the non-Newtonian fluid. The 65% stenosed model consistently exhibited higher pressure drops and flow irregularities. Fractional flow reserve (FFR) analysis confirmed that a 65% luminal narrowing poses significant hemodynamic risk. The highest wall shear stress (WSS) values were localized in the stenotic region, contributing to disturbed flow patterns and increased turbulence downstream. The non-Newtonian fluid model revealed that WSS was more sensitive to flow alterations, emphasizing the role of shear-dependent viscosity in vascular hemodynamics. These findings underscore the critical influence of hemodynamic parameters—such as pulse rate, viscosity, and arterial geometry—on cardiovascular performance. The study further highlights the detrimental impact of arterial stenosis on blood flow behavior and energy expenditure, with implications for clinical diagnosis and treatment planning in cardiovascular diseases.