Hemodynamical analysis of MHD two phase blood flow through a curved permeable artery having variable viscosity with heat and mass transfer

Two-fluid flow of blood in a curved stenotic artery under pulsating condition

The present article focuses on the analysis of the two-phase flow of blood via a stenosed artery under the influence of a pulsatile pressure gradient. The core and plasma regions of flow are modeled using the constitutive relations of Herschel-Bulkley and the Newtonian fluids, respectively. The problem is modeled in a cylindrical coordinate system. A modest stenosis assumption is used to simplify the non-dimensional governing equations of the flow issue. An explicit finite difference approach is used to solve the resultant nonlinear system of differential equations while accounting for the provided boundary conditions. After the necessary adjustments have been made to the crucial non-dimensional parameters, an analysis of the data behind the huge image, such as axial velocity, temperature field, concentration wall shear stress, flow rate, and flow impedance, is conducted. The current study shows that the curvature of blood vessels plays a significant role in influencing blood velocity. Specifically, a unit increase in the curvature radius results in a 24% rise in blood velocity.

Effect of blood viscosity on the hemodynamics of arteriovenous fistulae based on numerical investigation

Arteriovenous fistula (AVF) is the most commonly used vascular access for hemodialysis in patients with end-stage renal disease. Vascular diseases such as atherosclerosis and thrombosis, triggered by altered hemodynamic conditions, are the main causes of access failure. Changes in blood viscosity accelerate access dysfunction by affecting local velocities and wall shear stress (WSS) distribution in the circulation. Numerical simulation was employed to analyze and compare the hemodynamic behavior of AVF under different blood viscosities (0.001-0.012 Pa∙s). An idealized three-dimensional model with end-to-side anastomosis was established. Transient simulations were conducted using pulsatile inlet velocity and outflow as boundary conditions. The simulation results reveal the blood flow state of AVF under different viscosity physiological conditions and derive the rule of change. When blood viscosity increases, the local velocity in the disturbed region slows down and the stagnation time becomes longer, resulting in increased deposition of substances. As blood viscosity increases, the level of shear stress on the entire wall of the fistula increases accordingly. WSS values at high viscosities above 0.007 Pa∙s showed significantly larger low-shear regions near the anastomosis and increased chances of inducing atheromatous plaques. This research has revealed the correlation between blood dynamic viscosity and the hemodynamic behavior of AVF. Elevated whole blood viscosity increases the incidence of access obstruction and vascular disease leading to fistula failure. The study provides a basis for optimizing the distribution of hemodynamic parameters in the fistula for hemodialysis patients.

Electroosmotic MHD ternary hybrid Jeffery nanofluid flow through a ciliated vertical channel with gyrotactic microorganisms: Entropy generation optimization

In this study, the computational analysis of entropy generation optimization for synthetic cilia regulated ternary hybrid Jeffery nanofluid (Ag-Au-TiO2/PVA) flow through a peristaltic vertical channel with swimming motile Gyrotactic microorganisms is investigated. Understanding the intricate interaction of multiple physical phenomena in biomedical applications is essential for optimizing entropy generation and advancing microfluidic systems. The characteristics of nanofluid are explored for the electroosmotic MHD fluid flow in the presence of thermophoresis and Brownian motion, viscous dissipation, Ohmic heating and chemical reaction. Using the appropriate transformations, a set of ordinary differential equations are created from the governing partial differential equations. The resulting ODEs are numerically solved using the shooting technique using BVP5C in MATLAB after applying the long-wavelength and low Reynolds number approximation. The velocity, temperature, concentration, electroosmosis, and microorganism density profiles are analyzed graphically for different emerging parameters. Graphical investigation of engineering interest quantities like heat transfer rate, mass transfer rate, skin friction coefficient, and entropy generation optimization are also presented. It is observed that the rate of mass transfer increases for increasing thermophoretic parameter, while reverse effect is noted for Brownian motion parameter, Schmidt number, and chemical reaction number. The outcomes of present study can be pertinent in studying Cilia properties of respiratory tract, reproductive system, and brain ventricles.

Entropy generation optimization of cilia regulated MHD ternary hybrid Jeffery nanofluid with Arrhenius activation energy and induced magnetic field

This study deals with the entropy generation analysis of synthetic cilia using a ternary hybrid nanofluid (Al-Cu-Fe2O3/Blood) flow through an inclined channel. The objective of the current study is to investigate the effects of entropy generation optimization, heat, and mass transfer on ternary hybrid nanofluid passing through an inclined channel in the proximity of the induced magnetic field. The novelty of the current study is present in studying the combined effect of viscous dissipation, thermophoresis, Brownian motion, exponential heat sink/source, porous medium, endothermic-exothermic chemical reactions, and activation energy in the proximity of induced magnetic field is examined. The governing partial differential equations (PDEs) are transformed into the ordinary differential equations (ODEs) using appropriate transformations. Applying the low Reynolds number and the long-wavelength approximation, resultant ODEs are numerically solved using shooting technique via BVP5C in MATLAB. The velocity, temperature, concentration, and induced magnetism profiles are visually discussed and graphically analyzed for various fluid flow parameters. Graphical analysis of physical interest quantities like mass transfer rate, heat transfer rate, entropy generation optimization, and skin friction coefficient are also graphically discussed. The entropy generation improves for enhancing values of Reynolds number, solutal Grashof number, heat sink/source parameter, Brinkman number, magnetic Prandtl number, and endothermic-exothermic reaction parameter while the reverse effect is noticed for chemical reaction and induced magnetic field parameter. The findings of this study can be applied to enhance heat transfer efficiency in biomedical devices, optimizing cooling systems, designing efficient energy conversion processes, and spanning from renewable energy technologies to aerospace propulsion systems.

Computer Simulations of EMHD Casson Nanofluid Flow of Blood through an Irregular Stenotic Permeable Artery: Application of Koo-Kleinstreuer-Li Correlations

A novel analysis of the electromagnetohydrodynamic (EMHD) non-Newtonian nanofluid blood flow incorporating CuO and Al2O3 nanoparticles through a permeable walled diseased artery having irregular stenosis and an aneurysm is analyzed in this paper. The non-Newtonian behavior of blood flow is addressed by the Casson fluid model. The effective viscosity and thermal conductivity of nanofluids are calculated using the Koo-Kleinstreuer-Li model, which takes into account the Brownian motion of nanoparticles. The mild stenosis approximation is employed to reduce the bi-directional flow of blood to uni-directional. The blood flow is influenced by an electric field along with a magnetic field perpendicular to the blood flow. The governing mathematical equations are solved using Crank-Nicolson finite difference approach. The model has been developed and validated by comparing the current results to previously published benchmarks that are peculiar to this study. The results are utilized to investigate the impact of physical factors on momentum diffusion and heat transfer. The Nusselt number escalates with increasing CuO nanoparticle diameter and diminishing the diameter of Al2O3 nanoparticles. The relative % variation in Nusselt number enhances with Magnetic number, whereas a declining trend is obtained for the electric field parameter. The present study's findings may be helpful in the diagnosis of hemodynamic abnormalities and the fields of nano-hemodynamics, nano-pharmacology, drug delivery, tissue regeneration, wound healing, and blood purification systems.