Numerical simulation of the transport of nanoparticles as drug carriers in hydromagnetic blood flow through a diseased artery with vessel wall permeability and rheological effects.

The present study considers the mathematical modelling of unsteady non-Newtonian hydro-magnetic nano-hemodynamics through a rigid cylindrical artery featuring two different stenoses (composite and irregular). The Ostwald-De Waele power-law fluid model is adopted to simulate the non-Newtonian characteristics of blood. Inspired by drug delivery applications for cardiovascular treatments, blood is considered doped with a homogenous suspension of biocompatible nanoparticles. The arterial vessel exhibits the permeability effect (lateral influx/efflux), and an external magnetic field is also applied in the radial direction to the flow. A combination of the Buongiorno and Tiwari-Das nanoscale models is adopted. The strongly nonlinear nature of the governing equations requires a robust numerical method, and therefore the finite difference technique is deployed to solve the resulting equations. Validation of solutions for the pure blood case (absence of nanoparticles) is included. Comprehensive solutions are presented for shear-thickening (n = 1.5) and shear-thinning (n = 0.5) blood flow for the effects of crucial nanoscale thermophysical, solutal parameters, and hydrodynamic parameters. Comparison of profiles (velocity, temperature, wall shear stress, and flow rate) is also made for composite and irregular stenosis. Colour visualization of streamline plots is included for pure blood and nano mediated blood both with and without applied magnetic field. The inclusion of nanoparticles (Cu/blood) within blood increases the axial velocity of blood. By applying external magnetic field in the radial direction, axial velocity is significantly damped whereas much less dramatic alterations are computed in blood temperature and concentration profiles. The simulations are relevant to the diffusion of nano-drugs in magnetic targeted treatment of stenosed arterial diseases.

Numerical simulation of the transport of nanoparticles as drug carriers in hydromagnetic blood flow through a diseased artery with vessel wall permeability and rheological effects.

The present study considers the mathematical modeling of unsteady non-Newtonian hydro-magnetic nano-hemodynamics through a rigid cylindrical artery featuring two different stenoses (composite and irregular). The Ostwald-De Waele power-law fluid model is adopted to simulate the non-Newtonian characteristics of blood. Inspired by drug delivery applications for cardiovascular treatments, blood is considered doped with a homogenous suspension of biocompatible nanoparticles. The arterial vessel exhibits the permeability effect (lateral influx/efflux), and an external magnetic field is also applied in the radial direction to the flow. A combination of the Buongiorno and Tiwari-Das nanoscale models is adopted. The strongly nonlinear nature of the governing equations requires a robust numerical method, and therefore the finite difference technique is deployed to solve the resulting equations. Validation of solutions for the pure blood case (absence of nanoparticles) is included. Comprehensive solutions are presented for shear-thickening (n = 1.5) and shear-thinning (n = 0.5) blood flow for the effects of crucial nanoscale thermophysical, solutal parameters, and hydrodynamic parameters. Comparison of profiles (velocity, temperature, wall shear stress, and flow rate) is also made for composite and irregular stenosis. Colour visualization of streamline plots is included for pure blood and nano mediated blood both with and without applied magnetic field. The inclusion of nanoparticles (Cu/blood) within blood increases the axial velocity of blood. By applying external magnetic field in the radial direction, axial velocity is significantly damped whereas much less dramatic alterations are computed in blood temperature and concentration profiles. The simulations are relevant to the diffusion of nano-drugs in magnetic targeted treatment of stenosed arterial diseases.

Computational simulation of rheological blood flow containing hybrid nanoparticles in an inclined catheterized artery with stenotic, aneurysmal and slip effects.

Influenced by nano-drug delivery applications, the present article considers the collective effects of hybrid biocompatible metallic nanoparticles (Silver and Copper), a stenosis and an aneurysm on the unsteady blood flow characteristics in a catheterized tapered inclined artery. The non-Newtonian Carreau fluid model is deployed to represent the hemorheological characteristics in the arterial region. A modified Tiwari-Das volume fraction model is adopted for nanoscale effects. The permeability of the arterial wall and the inclination of the diseased artery are taken into account. The nanoparticles are also considered to have various shapes (bricks, cylinders, platelets, blades) and therefore the influence of different shape parameters is discussed. The conservation equations for mass, linear momentum and energy are normalized by employing suitable non-dimensional variables. The transformed equations with associated boundary conditions are solved numerically using the FTCS method. Key hemodynamic characteristics i.e. velocity, temperature, flow rate, wall shear stress (WSS) in stenotic and aneurysm region for a particular critical height of the stenosis, are computed. Hybrid nanoparticles (Ag-Cu/Blood) accelerate the axial flow and increase temperatures significantly compared with unitary nanoparticles (Ag/blood), at both the stenosis and aneurysm segments. Axial velocity, temperature and flow rate are all enhanced with greater nanoparticle shape factor. Axial velocity, temperature, wall shear stress and flow rate magnitudes are always comparatively higher at the aneurysm region compared with the stenotic segment. The simulations provide novel insights into the performance of different nanoparticle geometries and also rheological behaviour in realistic nano-pharmaco-dynamic transport and percutaneous coronary intervention (PCI).

Unsteady hybrid nanoparticle-mediated magneto-hemodynamics and heat transfer through an overlapped stenotic artery: Biomedical drug delivery simulation.

Two-dimensional laminar hemodynamics through a diseased artery featuring an overlapped stenosis was simulated theoretically and computationally. This study presented a mathematical model for the unsteady blood flow with hybrid biocompatible nanoparticles (Silver and Gold) inspired by drug delivery applications. A modified Tiwari-Das volume fraction model was adopted for nanoscale effects. Motivated by the magneto-hemodynamics effects, a uniform magnetic field was applied in the radial direction to the blood flow. For realistic blood behavior, Reynolds' viscosity model was applied in the formulation to represent the temperature dependency of blood. Fourier's heat conduction law was assumed and heat generation effects were included. Therefore, the governing equations were an extension of the Navier-Stokes equations with magneto-hydrodynamic body force included. The two-dimensional governing equations were transformed and normalized with appropriate variables, and the mild stenotic approximation was implemented. The strongly nonlinear nature of the resulting dimensionless boundary value problem required a robust numerical method, and therefore the FTCS algorithm was deployed. Validation of solutions for the particular case of constant viscosity and non-magnetic blood flow was included. Using clinically realistic hemodynamic data, comprehensive solutions were presented for silver, and silver-gold hybrid mediated blood flow. A comparison between silver and hybrid nanofluid was also included, emphasizing the use of hybrid nanoparticles for minimizing the hemodynamics. Enhancement in magnetic parameter decelerated the axial blood flow in stenotic region. Colored streamline plots for blood, silver nano-doped blood, and hybrid nano-doped blood were also presented. The simulations were relevant to the diffusion of nano-drugs in magnetic targeted treatment of stenosed arterial diseases.

Micropolar pulsatile blood flow conveying nanoparticles in a stenotic tapered artery: NON-Newtonian pharmacodynamic simulation.

Two-dimensional rheological laminar hemodynamics through a diseased tapered artery with a mild stenosis present is simulated theoretically and computationally. The effect of different metallic nanoparticles homogeneously suspended in the blood is considered, motivated by drug delivery (pharmacology) applications. The Eringen micropolar model has been discussed for hemorheological characteristics in the whole arterial region. The conservation equations for mass, linear momentum, angular momentum (micro-rotation), and energy and nanoparticle species are normalized by employing suitable non-dimensional variables. The transformed equations are solved numerically subject to physically appropriate boundary conditions using the finite element method with the variational formulation scheme available in the FreeFEM++ code. A good correlation is achieved between the FreeFEM++ computations and existing results. The effect of selected parameters (taper angle, Prandtl number, Womersley parameter, pulsatile constants, and volumetric concentration) on velocity, temperature, and micro-rotational (Eringen angular) velocity has been calculated for a stenosed arterial segment. Wall shear stress, volumetric flow rate, and hemodynamic impedance of blood flow are also computed. Colour contours and graphs are employed to visualize the simulated blood flow characteristics. It is observed that by increasing Prandtl number (Pr), the micro-rotational velocity decreases i.e., microelement (blood cell) spin is suppressed. Wall shear stress decreases with the increment in pulsatile parameters (B and e), whereas linear velocity increases with a decrement in these parameters. Furthermore, the velocity decreases in the tapered region with elevation in the Womersley parameter (α). The simulations are relevant to transport phenomena in pharmacology and nano-drug targeted delivery in hematology.

Mixed convective boundary layer flow over a vertical wedge embedded in a porous medium saturated with a nanofluid: Natural Convection Dominated Regime.

A boundary layer analysis is presented for the mixed convection past a vertical wedge in a porous medium saturated with a nano fluid. The governing partial differential equations are transformed into a set of non-similar equations and solved numerically by an efficient, implicit, iterative, finite-difference method. A parametric study illustrating the influence of various physical parameters is performed. Numerical results for the velocity, temperature, and nanoparticles volume fraction profiles, as well as the friction factor, surface heat and mass transfer rates have been presented for parametric variations of the buoyancy ratio parameter Nr, Brownian motion parameter Nb, thermophoresis parameter Nt, and Lewis number Le. The dependency of the friction factor, surface heat transfer rate (Nusselt number), and mass transfer rate (Sherwood number) on these parameters has been discussed.