Rheological Behavior of Physiological Pulsatile Flow through a Model Arterial Stenosis with Moving Wall

Abstract

The paper presents a numerical investigation of non-Newtonian modeling effects on unsteady periodic flows in a two-dimensional (2D) constricted channel with moving wall using finite volume method. The governing Navier-Stokes equations have been modified using the Cartesian curvilinear coordinates to handle complex geometries, such as, arterial stenosis. The physiological pulsatile flow has been used at the inlet position as an inlet velocity. The flow is characterized by the Reynolds numbers 300, 500, and 750 that are appropriate for large arteries. The investigations have been carried out to characterize four different non-Newtonian constitutive equations of blood, namely, the (i) Carreau, (ii) Cross, (iii) Modified-Casson, and (iv) Quemada. In these four models, blood viscosity is a nonlinear function of shear rates. The Newtonian model has been investigated to study the physics of fluid and the results are compared with the non-Newtonian viscosity models. The numerical results are presented in terms of streamwise velocity, wall shear stress, pressure distribution as well as the vorticity, streamlines, and vector plots indicating recirculation zones at the poststenotic region. Comparison has also been illustrated in terms of wall pressure and wall shear stress for the Cross model considering different amplitudes of wall oscillation.

A parametric investigation of blood flow in a wedge with non‐uniform viscosity and wall friction

“…The idea of using viscosity distribution function as appears in (25) is due to the theoretical and experimental results of blood viscosity behavior that obtained by Cerny and Walawender [4] and Pontrelli [44] and many others [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] as appear in…”

“…Likewise the Newtonian case, it is easy to deduce from Equation (2) that also the non-Newtonian velocity is decreased with the radial distance increase which also fits with the literature results. [5,44,[46][47][48][49][50]52,53] Also, the value of has a significant impact on the Newtonian fluid according to [56]. In addition, the effect of the wedge semiangle ( ) on the velocity ( ) is not 'tolerable' (92%) when comparing the error between the approximate and the numerical solutions, i.e., while increasing the angle from = 1 0 to = 10 0 so that assumption (61) for 2 ≪ 1 is no longer valid.…”

“…[50,51] However, excluding some points of distinction these assumptions are still valid and are well supported by literature. [52] Some other limited configurations like vertical channel [53] and even different cross section channels [54] have shown similar velocity behavior in the qualitative aspect. Different pressure modeling types (axial and hydrostatic pressures distribution) are examined and discussed in the present study.…”

“…Analytic analysis will be performed for small and high semi-wedge angles with various friction coefficients. The results will be compared qualitatively with the available literature data information [44][45][46][47][48][49][50][51][52][53][54] and hopefully, contribute to the biomed and polymer scientific areas.…”

Pulsatile Non-Newtonian Fluid Flows in a Model Aneurysm with Oscillating Wall

“…Rabby et al (2014) studied the Newtonian laminar fluid flow in an axisymmetric stenosis for the Reynolds number Re = 300 with a mild oscillating wall. Later on, Shupti et al (2015) have investigated the non-Newtonian fluid flow behavior through a single stenosis of maximum 60% area reduction with moving wall. In the presence of a single stenosis, for the higher Reynolds number, the flow becomes asymmetric that leads them to do further studies couples with stenosis and aneurysm.…”