Mathematical modelling of pulsatile flow of Casson’s fluid in arterial stenosis
ABSTRACT The effects of non-Newtonian nature of blood and pulsatility on flow through a stenosed artery have been investigated. It is of interest to note that the thickness of the viscous flow region changes with axial distance. An important result is that the mean and steady flow rates decrease as the yield stress increases. The critical value of the yield stress at which the flow rate behaviour changes from one type to another has been determined. Another important result of pulsatility is the mean resistance to flow is greater than its steady flow value, whereas the mean value of the wall shear for pulsatile blood flow is equal to steady wall shear stress. The velocity profiles and associated physiological characteristics involved in the analysis have been determined. Many standard results regarding Casson and Newtonian fluids flow, uniform and steady flow in an artery can be obtained in the present analysis as the special cases.
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ABSTRACT: Effect of heat and mass transfer on the blood flow through a tapered artery with stenosis is examined assuming blood as Jeffrey fluid. The governing equations have been modelled in cylindrical coordinates. Series solutions are constructed for the velocity, temperature, concentration, resistance impedance, wall shear stress and shearing stress at the stenosis throat. Attention has been mainly focused to the analysis of embedded parameters in converging, diverging and non-tapered situations.
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ABSTRACT: A nonlinear two-dimensional pulsatile blood flow through a stenosed artery is investigated by treating the deformable vascular wall as an elastic cylindrical tube containing the Newtonian fluid. In order to establish a resemblance to the in vivo conditions, the mathematical model of an improved shape of the time-variant overlapping stenosis is considered in the tapered arterial lumen. By applying a suitable coordinate transformation, the tapered cosine-shaped artery becames a non-tapered rectangular and rigid artery. The continuity and the nonlinear momentum equations are numerically solved under the appropriate physically realistic prescribed boundary conditions. In order to solve the resulting simultaneous equation system, the finite difference approximation code is developed and utilized. The effects of the taper angle, wall deformation, and severity of the stenosis within its fixed length on velocity profiles, volumetric flow rate, and resistive impedance are studied considering their dependencies with time. The present results are found in agreement with similar data from the literature.Journal of the Brazilian Society of Mechanical Sciences and Engineering 01/2014; · 0.24 Impact Factor
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ABSTRACT: This article is concerned with the analysis of pulsatile flow of blood through a stenosed artery including the effects of external body acceleration. The pulsatile flow behavior of blood in an artery under stenotic conditions subject to the pulsatile pressure gradient and external body acceleration has been studied. The effects of pulsatility, stenosis, body acceleration, yield stress and impedance have been investigated by modeling blood as a Casson fluid. It is observed that the yield stress of the fluid and body acceleration highly influenced the velocity of the fluid, shear stress, flow rate and impedance in a stenosed artery. It is interesting to note that the body acceleration enhances the flow rate and reduces the impedance.