Electromagnetohydrodynamic pulsatile blood flow of Casson nanofluid with stenosis porous artery under periodic body acceleration and slip effects: A Reynolds and Vogel viscosity models.

Effect of body acceleration on unsteady pulsatile flow of non-newtonian fluid through a stenosed artery

This study analyses the pulsatile flow of blood through narrow arteries with mild asymmetric stenosis. Blood is modeled as a two-fluid model with the suspension of all the erythrocytes in the core region being treated as Casson fluid and the plasma in the peripheral layer being assumed as Newtonian fluid. Perturbation method is used to solve the resulting coupled implicit system of non-linear partial differential equations. The expressions for shear stress, velocity, wall shear stress, plug core radius, flow rate and resistance to flow are obtained. The effects of pulsatility, stenosis shape parameter, stenosis depth, peripheral layer thickness, body acceleration and non-Newtonian behavior of blood on these flow quantities are discussed. It is noted that the plug core radius and resistance to flow decrease with the increase of the body acceleration and pressure gradient. It is observed that the velocity and flow rate increase with the increase of the peripheral layer thickness and they decrease with the increase of the stenosis shape parameter. It is recorded that the estimates of the mean flow rate of the two-fluid blood flow model are considerably higher than that of the single-fluid blood flow model. It is also noticed that the presence of body acceleration and peripheral layer influences the mean flow rate by increasing their magnitude significantly in the arteries with different radii.

A mathematical model has been proposed to study the pulsatile flow of a power-law fluid through rigid circular tubes under the influence of a periodic body acceleration. Numerical solutions have been obtained by using finite difference method. The accuracy of the numerical procedure has been checked by comparing the obtained numerical results with other numerical and analytical solutions. It is found that the agreement between them is quite good. Interaction of non-Newtonian nature of fluid with the body acceleration has been investigated by using the physiological data for two particular cases (coronary and femoral arteries). The axial velocity, fluid acceleration, wall shear stress and instantaneous volume flow rate have been computed and their variations with different parameters have been analyzed. The following important observations have been made: (i) The velocity and acceleration profiles can have more than one maxima, this is in contrast with usual parabolic profiles where they have only one maximum at the axis. As n increases, the maxima shift towards the axis; (ii) For the flow with no body acceleration, the amplitude of both, wall shear and flow rate, increases with n, whereas for the flow with body acceleration, the amplitude of wall shear (flow rate) increases (decreases) as n increases; (iii) In the absence of body acceleration, pseudoplastic (dilatant) fluids, with low frequency pulsations, have higher (lower) value of maximum flow rate Qmax than Newtonian fluids, whereas for high frequencies, opposite behavior has been observed; for flow with body acceleration pulsations gives higher (lower) value of Qmax for pseudoplastic (dilatant) fluids than Newtonian fluids.

Purpose This study aims to numerically investigate the unsteady blood flow through an inclined, overlapping, time-variant stenosed artery under the influence of uniform magnetic and electric fields. A Casson fluid model is used to account for non-Newtonian hemorheological behavior, with blood viscosity modeled as hematocrit-dependent. The second law of thermodynamics is applied to evaluate entropy generation and flow irreversibility in the presence of nanoparticles. Design/methodology/approach The governing equations for non-Newtonian, electromagnetohydrodynamic blood flow are solved using an explicit finite difference scheme (FTCS). Hemodynamic parameters, such as velocity, temperature, entropy generation and Bejan number, are computed across varying hematocrit levels and nanoparticle types (Au and TiO2). Findings The results indicate that hematocrit and temperature difference are the most influential dimensionless parameters affecting entropy generation. Au/blood nanofluids exhibit consistently higher velocity and temperature profiles compared to TiO2/blood nanofluids. Regions of high entropy correspond to zones of intense shear and thermal gradients. The applied electric field enhances flow via electro-osmotic effects, while increasing hematocrit leads to higher flow resistance and energy dissipation. Originality/value Unlike prior studies that assume constant blood viscosity, this work incorporates hematocrit-dependent viscosity and evaluates the combined effects of magnetic and electric fields on entropy generation. The results offer deeper insight into thermodynamic efficiency in stenosed arteries and can inform biomedical applications in targeted drug delivery, blood purification and vascular device design.

In this analysis, we present a theoretical study to examine the combined effect of both slip velocity and periodic body acceleration on an unsteady generalized non-Newtonian blood flow through a stenosed artery with permeable wall. A constant transverse magnetic field is applied on the peristaltic flow of blood, treating it as an elastico-viscous, electrically conducting and incompressible fluid. Appropriate transformation methods are adopted to solve the unsteady non-Newtonian axially symmetric momentum equation in the cylindrical polar coordinate system with suitably prescribed conditions. To validate the applicability of the proposed analysis, analytical expressions for the axial velocity, fluid acceleration, wall shear stress and volumetric flow rate are computed and for having an adequate insight to blood flow behavior through a stenosed artery, graphs have been plotted with varying values of flow variables, to analyse the influence of the axial velocity, wall shear stress and volumetric flow rate of streaming blood.

This article aims to discuss the flow of nanoparticles in the blood through a stenosed artery in the presence of a magnetic field and periodic body acceleration. The overlapping shape of stenosis is chosen to show the impact of blood flow. The Bingham plastic fluid model is utilized to capture the non-Newtonian behavior of blood in the stenosed artery under diseased conditions. The resultant equations are solved analytically using the regular perturbation method. The impact of various emerging parameters on velocity, flow rate, effective viscosity, and wall shear stress are presented through graphs and discussed in detail. It is noticed that liquid velocity and flow rate increase whereas effective viscosity decreases with an increase in slip velocity and Womersley’s frequency parameter. It is also noted that liquid velocity and flow rate are decreased by enhancing the Lorentz force. The increase in body acceleration enhances fluid velocity.

Peristaltic pumping of non –Newtonian fluid generally arises in physiological and engineering applications. The study of the peristaltic transport has become quite interested to several scientists because of its various applications in science and engineering. The objective of the present study is to discuss the peristaltic transport of a Jeffrey fluid with temperature - dependent viscosity in an endoscope (modelled as cylindrical annulus) with partial slip. The effect of variable viscosity in a Jeffrey fluid flow associated with partial slip was not considered till to date. We considered the Vogel's viscosity model. The expressions for temperature, velocity and stream function was obtained by using regular perturbation method in terms of small viscosity parameter. We investigated that the pressure rise decreases with increasing Jeffrey parameter. Graphical effects are presented understand the physical characteristics of different parameters.

In the present time, cardiovascular disorders represent a significant global health concern because of the intricate arterial constrictions and impaired hemodynamics. Traditional drug administration methods frequently lack site‐specific targeting capability, leading to reduced therapeutic efficiency and may affect healthy tissues. Now‐a‐days, nanoparticle‐assisted drug delivery technologies are recognized as an effective strategy for treating cardiovascular diseases. Based on these applications, this novel study that incorporates the gold nanoparticles in the bloodstream, investigates the hemodynamic characteristics through a diseased time‐variant arterial structure with different geometrical configurations namely converging, non‐tapered, and diverging. The present model incorporates the several physical aspects such as thermal radiation, heat source, porous medium, magnetic field, and body acceleration in the present scenario. The governing flow equations of nanofluid transport model are simplified with the nondimensional variables and mild‐stenosis approximations. The forward time‐centered space (FTCS) finite difference method is utilized to get the approximate solution of the present model. The model explores the influence of several key parameters such as Darcy paramter, radiation parameter, nanoparticle volume fraction, heat parameter, nanoparticle shape parameter, tapering parameter, and magnetic number on the various hemodynamic quantities such as wall shear stress, impedance, flow rate, Nusselt number, temperature, and velocity. The results reveal that the gold nanoparticles help to regulate the blood velocity by 13.85% and temperature by 5.64% in the stenosed arterial region. The wall shear stress reveals descending trend across the arterial geometries and achieved its highest value in converging artery, moderate value in non‐tapered artery, and lowest value in diverging artery. The findings of the present model may offer the therapeutic possibilities of arterial diseases such as targeted drug delivery, diagnosis of tumors and brain aneurysms, and magnetic hyperthermia treatment.

Hjman bodies may occasionally be subjected to high external accelerations. The response of the vascular system under such situations has recently been the subject of several theoretical and experimental studies. However, little work appears to have so far been carried out on the analysis of blood flow in stenosed artery in the presence of body accelerations. In the paper we present a model of blood flow in a partially occluded tube subject to both the pulsatile pressure gradient due to the normal heart action and the periodic body acceleration. Closed-form solutions have been obtained for the instantaneous rate of flow and for the distributions of flow velocity, acceleration and shear stress over the stenosed length. Computational results corresponding to a stenosed carotid artery are presented and discussed.

Particle–fluid two phase modeling of electro-magneto hydrodynamic pulsatile flow of Jeffrey fluid in a constricted tube under periodic body acceleration

Pulsatile flow of blood and heat transfer with variable viscosity under magnetic and vibration environment

In the present paper, the magnetohydrodynamics effects on flow parameters of blood carrying magnetic nanoparticles flowing through a stenosed artery under the influence of periodic body acceleration are investigated. Blood is assumed to behave as a Casson fluid. The governing equations are nonlinear and solved numerically using finite difference schemes. The effects of stenotic height, yield stress, magnetic field, particle concentration and mass parameters on wall shear stress, flow resistance and velocity distribution are analysed. It is found that wall shear stress and flow resistance values are considerably enhanced when an external magnetic field is applied. The velocity values of fluid and particles are appreciably reduced when a magnetic field is applied on the model. It is significant to note that the presence of nanoparticles, magnetic field and yield stress tend to increase the plug core radius. Increased wall shear stress and flow resistance affects the circulation of blood in the human cardiovascular system. The results obtained from the study can be used in normalizing the values of the model parameters and hence can be used for medical applications. The presence of magnetic field helps to slow down the flow of fluid and magnetic particles associated with it. The magnetic particles of nanosize developed in recent days are biodegradable and used in biomedical applications. Biomagnetic principles and biomagnetic particles as drug carriers are used in cancer treatments.

The present research examines the unsteady sensitivity analysis and entropy generation of blood-based silver–titanium dioxide flow in a tilted cylindrical W-shape symmetric stenosis artery. The study considers various factors such as the electric field, joule heating, viscous dissipation, and heat source, while taking into account a two-dimensional pulsatile blood flow and periodic body acceleration. The finite difference method is employed to solve the governing equations due to the highly nonlinear nature of the flow equations, which requires a robust numerical technique. The utilization of the response surface methodology is commonly observed in optimization procedures. Drawing inspiration from drug delivery techniques used in cardiovascular therapies, it has been proposed to infuse blood with a uniform distribution of biocompatible nanoparticles. The figures depict the effects of significant parameters on the flow field, such as the electric field, Hartmann number, nanoparticle volume fraction, body acceleration amplitude, Reynolds number, Grashof number, and thermal radiation, on velocity, temperature (nondimensional), entropy generation, flow rate, resistance to flow, wall shear stress, and Nusselt number. The velocity and temperature profiles improve with higher values of the wall slip parameter. The flow rate profiles increase with an increment in wall velocity but decrease with the Womersley number. Increasing the intensity of radiation and decreasing magnetic fields both result in a decrease in the rate of heat transfer. The blood temperature is higher with the inclusion of hybrid nanoparticles than the unitary nanoparticles. The total entropy generation profiles increase for higher values of the Brickman number and temperature difference parameters. Unitary nanoparticles exhibit a slightly higher total entropy generation than hybrid nanoparticles, particularly when positioned slightly away from the center of the artery. The total entropy production decreases by 17.97% when the thermal radiation is increased from absence to 3. In contrast, increasing the amplitude of body acceleration from 0.5 to 2 results in a significant enhancement of 76.14% in the total entropy production.

The present study investigates the effect of periodic body acceleration on solute dispersion in blood flow through large arteries. Transport coefficients (i.e., exchange, convection, and dispersion coefficients) and mean concentration of the solute are analyzed in the presence of wall absorption. The solute is quickly transported to the wall of arteries with a smaller radius, whereas the opposite is true for arteries with a larger radius. In the presence of body acceleration, the amplitude of fluctuations of the convection coefficient K1(t) increases significantly as the radius of the artery increases. In contrast, an opposite scenario exists for the dispersion coefficient K2(t). The solute dispersion process becomes more effective in arterial blood flow as the radius of the artery decreases. More interestingly, in large arteries with body acceleration, the solute is convected, dispersed, and distributed more toward the upstream direction owing to flow reversal during the diastolic phase of pressure pulsation. Note that this important feature of flow reversal is solely due to periodic body acceleration. For an artery with a small radius, under the influence of periodic body acceleration, the mean concentration of solute Cm is the minimum, and more axial spread is noticed in the axial direction. In contrast, an opposite scenario arises in the artery with a large radius. Additionally, the effect of body acceleration on the shear-induced diffusion of red blood cells is discussed in blood flow.

The present study investigates the magnetohydrodynamic (MHD) flow characteristics of a blood-based ternary nanofluid (Au/Cu/Al2O3-blood) in stenosed arteries, with a focus on symmetry-inspired modeling rooted in the axial symmetry of arterial geometry and the symmetric distribution of external physical fields (magnetic field, thermal radiation). The findings offer significant insights into the realm of hyperthermia therapy and targeted drug delivery within the domain of biomedical engineering. A mathematical model is established under a cylindrical coordinate system (consistent with arterial axial symmetry), integrating key physical effects (thermal radiation, chemical reactions, viscous dissipation, body acceleration) and fractional-order dynamics via Caputo derivatives—while ensuring the symmetry of governing equations in time and space. The numerical solutions for velocity and temperature profiles are obtained using the Laplace transform and Concentrated Matrix-Exponential (CME) method, a technique that preserves symmetric properties during the solution process. The results of the study indicate the following: The Hartmann number, which is increased, has been shown to reduce axial velocity due to the Lorentz force, thereby maintaining radial symmetry. Furthermore, thermal radiation has been demonstrated to raise fluid temperature, a critical factor in heat-based therapies, with the temperature field evolving symmetrically. In addition, it has been observed that ternary nanoparticles outperform single and binary systems in heat and mass transfer via symmetric dispersion. This work contributes to the existing body of knowledge by integrating symmetry principles into the study of fractional dynamics, electromagnetic fields, and body acceleration modeling. It establishes a comprehensive biomedical flow framework. It is imperative that future research explore pulsatile flow under symmetric boundaries and validate the model through experimental means.