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In the present work, the impact of periodic body acceleration on the unsteady flow of blood in an inclined artery has been investigated. The blood is represented by an incompressible, viscous, non-Newtonian Jeffrey fluid. The artery is assumed to have mild overlapping stenoses inside its lumen. The perturbation method is used to solve the governing nonlinear coupled partial differential equations. Here, the Womersley frequency parameter is considered small enough for blood flow through arteries. Analytic expressions for the wall shear stress, stress at the critical height of stenosis, velocity profile, volumetric flow rate, pressure drop, resistive impedance, and effective viscosity are obtained using the perturbation technique. Regarding different flow parameters, the effects of body acceleration, pulsatility, the non-Newtonian character of blood, and velocity slip are examined and graphically depicted. It is concluded from the present analysis that the flow impedance rises when the stenosis reaches its critical height, but it falls as the velocity slip at the wall increases. It is also observed that when body acceleration increases, flow rate, velocity, and shear stress near the critical height of stenosis all rise, whereas wall shear stress decreases as body acceleration rises. Here, we also analyzed the flow pattern of the non-Newtonian Jeffrey fluid when it passes through the overlapped stenosed artery with the help of streamlines. The results of the present problem have been verified with the previous existing results in the literature. [ABSTRACT FROM AUTHOR]

AbstractResearch on blood flow in diseased arteries has become a priority in recent years. Stenosis/aneurysm is the most common arterial diseases. This work investigates the mixed effect of electric and magnetic fields on the unsteady, two-dimensional, laminar, non-Newtonian pulsatile flow of blood in an axisymmetrically inclined tapered porous artery with stenosis and aneurysm containing gold nanoparticles, subjected to body acceleration and slip effect. Thermal radiation and heat sources are also included. To immobilize the effect of the vessel wall, we use a radial coordinate transformation. The nonlinear partial differential equations governing the present problem, together with the prescribed boundary conditions, are solved using an explicit finite-difference scheme. The current analysis could help to understand the improvement in mass distribution and heat transfer in diseased blood vessels, which might be useful for drug delivery in the therapy of stenosis and aneurysm. [ABSTRACT FROM AUTHOR]

Abstract Background The seeds of many plant species can be dispersed over long distances in animal fur (epizoochory). Quantifying epizoochory in the wild is, however, challenging, since it is difficult to measure the retention times of seeds in fur. These retention times depend on the acceleration that seeds experience and that can detach seeds from fur. Wildlife collars containing accelerometers may thus provide crucial information on epizoochorous seed dispersal. However, this is only the case if acceleration of the animal’s neck (where collars are attached) is informative of acceleration of the animal’s main body (where most seeds are transported). Methods We used accelerometers to simultaneously measure acceleration at the neck, breast and the upper hind leg of 40 individuals of eight mammal species spanning a large range of body masses (26–867 kg). We then quantified maximum acceleration as the 95%-quantile of the resultant acceleration (of all measured values in data intervals of 5 s). Results Maximum acceleration was comparable between the neck and breast but substantially higher at the hind leg. Maximum acceleration measured by neck collars and body mass jointly explained 81% of the variance in maximum acceleration of the breast and 62% of the variance in maximum acceleration of the leg. Conclusions Acceleration measured by neck collars is informative of the acceleration experienced by seeds attached to other body parts (breast and leg). When combined with animal movement data and lab measurements of how fur acceleration affects seed release and retention times, widely used collar accelerometers can thus be used to assess distances of epizoochorous seed dispersal.

The effect of body acceleration on the pulsatile flow of blood through the elliptical artery having stenosis at the multiple positions of its wall is investigated in the current study. The artery is inclined at angle θ with horizontal, and blood is considered as Casson fluid. The mathematical model is processed into non-dimensional form and simplified using assumptions of mild stenosis. The analytical solution of mathematical equations is obtained in the elliptic bounded domain by employing the perturbation technique with Womersley frequency as a perturbation parameter and validated through case comparison with the previous study. The impacts of external acceleration, stenosis height, shape, gravitational acceleration, yield stress, and inclination angle on the flow velocity, flow rate, wall shear stress, and flow resistance are analyzed. It is found that body acceleration, gravitational acceleration, and inclination angle increase the flow rate and diminish the frictional resistance. The more significant yield stress and stenosis height enhance the flow resistance and reduce the flow rate. Moreover, fluid has higher velocity in the case of the non-symmetric shape of stenosis compared with the symmetric form.

The present paper analyzes an unsteady magnetohydrodynamic blood flow model of an visco-elastic fluid through an inclined porous stenosed artery with body acceleration and slip effect. Navier-Stokes equations have been used to describe the blood flow model. The governing equation of blood flow is solved by an analytic method by considering blood as an incompressible, visco-elastic fluid, and suspension of RBC’s in plasma. Axial velocity, blood acceleration, flow rate, and shear stress are derived numerically by using the finite Laplace and Hankel transformation and their inverse. The effect of parameters such as the visco-elasticity parameter, Womersley number, Hartmann number, inclination angle, parameter of slip, and body acceleration frequency is analyzed. Axial velocity reduces as the Hartmann number and visco-elasticity parameter enhance and it enhances with the enhancement of the slip parameter and inclination angle. The study is beneficial for finding the effect of slip parameter, porosity factor and Hartmann number when a human body is exposed to MRI and CT scan.

Background: The seeds of many plant species can be dispersed over long distances in animal fur (epizoochory). Quantifying epizoochory in the wild is, however, challenging, since it is difficult to measure the retention times of seeds in fur. These retention times depend on the acceleration that seeds experience and that can detach seeds from fur. Wildlife collars containing accelerometers may thus provide crucial information on epizoochorous seed dispersal. However, this is only the case if acceleration of the animal's neck (where collars are attached) is informative of acceleration of the animal's main body (where most seeds are transported). Methods: We used accelerometers to simultaneously measure acceleration at the neck, breast and the upper hind leg of 40 individuals of eight mammal species spanning a large range of body masses (26–867 kg). We then quantified maximum acceleration as the 95%-quantile of the resultant acceleration (of all measured values in data intervals of 5 s). Results: Maximum acceleration was comparable between the neck and breast but substantially higher at the hind leg. Maximum acceleration measured by neck collars and body mass jointly explained 81% of the variance in maximum acceleration of the breast and 62% of the variance in maximum acceleration of the leg. Conclusions: Acceleration measured by neck collars is informative of the acceleration experienced by seeds attached to other body parts (breast and leg). When combined with animal movement data and lab measurements of how fur acceleration affects seed release and retention times, widely used collar accelerometers can thus be used to assess distances of epizoochorous seed dispersal. [ABSTRACT FROM AUTHOR]

This article examines a mathematical framework that describes the versatile behavior of heat and mass exchange in blood flowing through a narrowed vessel having multiple stenoses. The geometry of a channel having multiple stenoses with an asymmetrical axial axis and a symmetrical radial axis can be visualized by applying a suitable mathematical expression. The geometry of the chosen model considers the height and shape of stenoses. The modification in shape parameter is used to capture variations in the shape of the stenoses in the artery. The blood is supposed to be isochoric (incompressible), while its rheological behavior is characterized by Williamson's fluid model. The transfer of momentum is analyzed using the equation of motion in cooperation with the continuity equation. In addition, the equations of heat conduction and diffusion are utilized, respectively, to illustrate the distributions of heat and mass. Simplified forms of momentum, mass, and heat transport equations are achieved by incorporating dimensionless quantities and moderate stenosis conditions. A well-known explicit finite difference approach is utilized to solve the emergent non-linear system of governing equations numerically. The influence of different evolving parameters on the flow field along with mass and heat distributions is illustrated through various plots. [ABSTRACT FROM AUTHOR]

In this paper, we construct the exact solution of blood flow of Oldroyd-B fluids to represent the non-Newtonian characteristics of biofluids and to study the unsteady flow of blood and heat transfer through arterial segment with external magnetic field applied normal to the flow direction in the presence of thermal radiation and body acceleration. In the study, we investigate the influence of Caputo time-fractional parameter, heat transfer, external body acceleration, and magnetic field on the blood velocity and temperature distribution in a straight circular cylindrical vessel. The constitutive partial differential equation and temperature equation governing blood flow in the arterial wall are solved using Laplace and finite Hankel transforms. In addition, Gaver Stehfest's algorithm is used for the inverse Laplace transform. The results obtained are interpreted graphically and discussed from the physiological point of view. The graphs show that the rate of heat transfer and blood velocity become less with the increase in the external magnetic field strength which is very good in regulating blood flow as well as temperature distribution during treatment. Based on the graphical representations, blood velocity and temperature distribution both decrease in ascending order of the fractional parameter as memory effect. Further, owing to the dissipation of energy caused by blood viscoelasticity and magnetic field effect, during pulsatile flow of blood, the heat transfer rate at the wall of the artery is enhanced. The significance of this study can be found in the application fields such as biomedical engineering, medicine and pathology. [ABSTRACT FROM AUTHOR]

The present paper analyzes an unsteady magnetohydrodynamic blood flow model of an visco-elastic fluid through an inclined porous stenosed artery with body acceleration and slip effect. Navier-Stokes equations have been used to describe the blood flow model. The governing equation of blood flow is solved by an analytic method by considering blood as an incompressible, visco-elastic fluid, and suspension of RBC's in plasma. Axial velocity, blood acceleration, flow rate, and shear stress are derived numerically by using the finite Laplace and Hankel transformation and their inverse. The effect of parameters such as the visco-elasticity parameter, Womersley number, Hartmann number, inclination angle, parameter of slip, and body acceleration frequency is analyzed. Axial velocity reduces as the Hartmann number and visco-elasticity parameter enhance and it enhances with the enhancement of the slip parameter and inclination angle. The study is beneficial for finding the effect of slip parameter, porosity factor and Hartmann number when a human body is exposed to MRI and CT scan. [ABSTRACT FROM AUTHOR]

Supervised learning of behavioural modes from body acceleration data has become a widely used research tool in Behavioural Ecology over the past decade. One of the primary usages of this tool is to estimate behavioural time budgets from the distribution of behaviours as predicted by the model. These serve as the key parameters to test predictions about the variation in animal behaviour. In this paper we show that the widespread computation of behavioural time budgets is biased, due to ignoring the classification model confusion probabilities.Next, we introduce the confusion matrix correction for time budgets—a simple correction method for adjusting the computed time budgets based on the model's confusion matrix.Finally, we show that the proposed correction is able to eliminate the bias, both theoretically and empirically in a series of data simulations on body acceleration data of a fossorial rodent species (Damaraland mole‐rat Fukomys damarensis).Our paper provides a simple implementation of the confusion matrix correction for time budgets, and we encourage researchers to use it to improve accuracy of behavioural time budget calculations. [ABSTRACT FROM AUTHOR]

A mathematical model of physiological pulsatile flow of blood through a stenotic flexible artery in the presence of body acceleration is presented in this paper. Streaming blood is considered as a shear-thinning non-Newtonian fluid as proposed by Yeleswarapu (Evaluation of continuum models for characterizing the constitutive behaviour of blood, Ph.D. thesis, Dept. Mech. Eng., University of Pittsburgh, 1996), and a physiological pulsatile flow rate proposed by Pedrizzetti (J Fluid Mech 310:89–111, 1996) has been taken through the tube. Deformation of vessel wall is modelled as a function of flow rate. This computational study of an idealized model may bring some insights for realistic blood flow through a stenotic artery. The novelty of this work lies in the fact that realistic flow of blood through a stenosed artery has been studied as far as possible and a new idea has been provided to describe the arterial wall motion. Governing equations in cylindrical polar coordinates are solved using stream function–vorticity method. Behaviour of various flow quantities is investigated through a parametric study. It is noted that the degree of constriction and body acceleration have important impacts on the haemodynamic parameters such as wall shear stress, oscillatory shear index, and relative residence time. Increasing body acceleration enhances the peak value of wall shear stress, but reduces the oscillatory shear index and relative residence time. Almost 1/4th increase in length of flow separation is found when Froude number raises its value from 0.1 to 0.5, other parametric values remaining fixed. On the other hand, almost 50% increase in the magnitude of the peak value of wall pressure is found when the amplitude of body acceleration takes a value 0.4 (A = 0.4) compared to the without body acceleration case (A = 0). These results have a significant role. [ABSTRACT FROM AUTHOR]

For real-world applications, a biped robot should maintain stable walking when subjected to sudden external disturbances. Typically, unexpected changes to body acceleration indicate that a robot is experiencing an external disturbance. This paper presents a biped walking controller for rapid response to large external disturbances. First, a novel adjustment algorithm for foot placement is proposed. Here, zero-moment point variations are mapped onto the new foothold based on calculations from changes in body acceleration. Second, a novel impact reduction control for foot landing is presented based on abating body vibrations. To avoid false detection triggers and excessive foothold adjustment, a rapid disturbance detection method is established using the body acceleration derivative. Finally, the effectiveness of the proposed methods is validated under simulations and in experiments with an actual biped robot. [ABSTRACT FROM AUTHOR]

This research focuses on numerical patterns of temperature distribution and blood flow through tapered arteries. The blood flow is considered as an incompressible and fully developed flow with Non-Newtonian nature assumed as modified Cross fluid which is inside a body under certain acceleration. Also, the impact of heat transfer regarding a single layer model on an unstable and pulsatile blood flow through a designed tapered artery with a combination of stenotic and aneurysm is investigated. The wall of artery is designed as an elastic tube, so, its geometry changes during the numerical computations is up to time. This research uses a suitable coordinate transformation to create an exact mesh with rectangular mesh units. In the case of the thermophysical parameters of blood flow field including the velocity pattern and temperature distributions, the governing equations are managed and solved based on the finite difference method and then, the reported results are discussed as a function of velocity and temperature. The outputs of this mathematical modeling are compared with some available and proved results in previous researches to confirm the accuracy and validity of the method. The variations in dynamic features of blood flow wall shear stress, volumetric flow rate and flow resistance can be analyzed and computed on basis of the pattern of velocity profile in assumed domain. Furthermore, contour plots of temperature and velocity for specified parameters are provided. [ABSTRACT FROM AUTHOR]

This study aims to examine the pulsatile ow of blood through tapered artery with a stenosis under the effects of body acceleration and external magnetic field. Blood ow is modeled as non-Newtonian micropolar uid. The non-linear governing equations of continuum and momentum in the cylindrical coordinate are being discretized using a finite difference approach and have been solved iteratively, through Crank-Nicolson method. The blood velocity distribution, volumetric ow rate and Resistance to blood ow at the stenosis throat are computed for various values of angle of tapering, amplitudes of body acceleration and Hartman number. It is shown that the results are in good agreement with the previous studies. [ABSTRACT FROM AUTHOR]

A mathematical study for two-phase unsteady pulsatile flow of blood through a vessel in the presence of body acceleration is presented in this paper. The blood in the core region is modeled as a non-Newtonian fluid while in the peripheral region it is described as a Newtonian fluid. The effects of body acceleration are also taken into account in this study. The continuity and momentum equations are used to model the proposed problem in terms of a nonlinear partial differential equation. This equation along with initial and boundary conditions is made dimensionless and then solved numerically using finite difference method. The behavior of various flow quantitates is analyzed through a parametric study.

The pulsatile flow of blood in narrow arteries with multiple-stenoses under body acceleration is analyzed mathematically, treating blood as (i) single-phase Herschel-Bulkley fluid model and (ii) two-phase Herschel- Bulkley fluid model. The expressions for various flow quantities obtained by Sankar and Ismail (2010) for single-phase Herschel-Bulkley fluid model and Sankar (2010c) for two-phase Herschel-Bulkley fluid model are used to compute the data for comparing these fluid models in a new flow geometry. It is noted that the plug core radius, wall shear stress and longitudinal impedance to flow are marginally lower for two-phase HB fluid model than those of the single-phase H-B fluid model. It is found that the velocity decreases significantly with the increase yield stress of the fluid and the reverse behavior is noticed for longitudinal impedance to flow. It is also noticed that the velocity distribution and flow rate are higher for two-phase Herschel-Bulkley fluid model than those of the single-phase Herschel-Bulkley fluid model. It is also recorded that the estimates of the mean velocity increase with the increase of the body acceleration and this behavior is reversed when the stenosis depth increases.

In the present study, a two-dimensional pulsatile blood flow model is created and the related heat transfer characteristics through a stenosed artery are investigated in the presence of a defined magnetic field with the body acceleration. The blood domain is assumed as a nonlinear, time-dependent, incompressible and laminar flow. The blood flow is considered with the unsteady characteristics because the pulsatile pressure gradient is arising due to the systematic reactions between the heart and the body acceleration. The non-linear momentum and continuity equations are solved with suitable initial and boundary conditions using the Crank-Nicolson scheme. In this study, the blood flow characteristics (velocity profiles, temperature, volumetric flow rate and flow resistance) are evaluated, also effects of the defined stenosis severity, the heat transfer factors and the considered magnetic field on the effective flow properties are discussed. Besides, the blood flow characteristics have been analyzed in a comparison form for two rigid and elastic arteries. Finally, it should be said that the present outputs are in good agreement with some available and validated results. [ABSTRACT FROM AUTHOR]

A mathematical model for two-dimensional pulsatile blood flow through a constriction vessels under magnetic field and body acceleration is numerically simulated. The artery considered as an elastic cylindrical tube and the geometry of the constriction assumed to time-dependent with an aim to provide resemblance to the in-vivo situations. The blood flow considered nonlinear, incompressible and fully developed. The nonlinear momentum and the continuity equations under suitable initial and boundary conditions can be numerically solved using the Crank-Nicolson scheme. The blood flow specifications such as the velocity profile, the volumetric flow rate and the resistance to flow are obtained and effects of the magnetic field and the severity of the stenosis under these flow specifications are discussed. Besides the blood flow characteristics through elastic artery have been compared with the rigid ones. [ABSTRACT FROM AUTHOR]

Currently, we cannot afford to spend much time for instructing usages of crutches for crutch users. However, we should carefully observe the methods of the patients' using crutches whether the methods are appropriate or not because inappropriate methods can raise a secondary accident such as falling. Therefore, it is desirable that patients are instructed readily on the proper method of using crutches when they start to use crutches. When considering the way of crutch walks, we took notice of the before/after body acceleration ratio, that is, the ratio between the accelerations before and after the gait mode-change as an important measure: from previous researches, it was found that there is a relationship between the body parts motions and the before/after body acceleration ratio of crutch users. Furthermore, it is desirable to get the before/after body acceleration ratio, without attaching any sensing devices onto the crutch user's body because the attached sensing devices may disturb a smooth walk. In order to meet the need, the authors proposed an estimation model of the before/after body acceleration ratio from the thigh motions without using any accelerometers. In this paper, as a measuring device, Kinect sensor was employed: although Kinect sensor is easy-to-use of, its measuring accuracy is not as precise as that of standard motion capturing systems. Firstly, the measuring accuracy of Kinect sensor was confirmed. Secondly, participants' crutch walk motions were practically measured by Kinect sensor. Then, the proposed estimation model was applied to the measured motions, and the effectiveness of the estimation model of the before/after body acceleration ratio was discussed. As a result, it was found that there was a high correlation between the estimated before/after body acceleration ratio and the measured one, and the before/after body acceleration ratio of a crutch user was successfully estimated by using the proposed method without an accelerometer nor a motion capturing system.

In this paper an attempt was made to simulate blood flow in a mobile human arterial network, specifically, in a running human subject. In order to simulate the effect of motion, a previously published immobile 1-D model was modified by including an inertial force term into the momentum equation. To calculate inertial force, gait analysis was performed at different levels of speed. Our results show that motion has a significant effect on the amplitudes of the blood pressure and flow rate but the average values are not effected significantly. [ABSTRACT FROM AUTHOR]

With an aim to investigate the effect of externally imposed body acceleration on two-dimensional, pulsatile blood flow through a stenosed artery is under consideration in this article. The blood flow has been assumed to be non-linear, incompressible and fully developed. The artery is assumed to be an elastic cylindrical tube and the geometry of the stenosis considered as time dependent, and a comparison has been made with the rigid ones. The shape of the stenosis in the arterial lumen is chosen to be axially non-symmetric but radially symmetric in order to improve resemblance to the in-vivo situations. The resulting system of non-linear partial differential equations is numerically solved using the Crank-Nicolson scheme by exploiting the suitably prescribed conditions. The blood flow characteristics such as the velocity profile, the volumetric flow rate and the resistance to flow are obtained and effects of the severity of the stenosis, the body acceleration on these flow characteristics are discussed. The present results are compared with literature and found to be in agreement. [ABSTRACT FROM AUTHOR]

This paper proposes a new method to improve accuracy and real-time performance of inertial joint angle estimation for upper limb rehabilitation applications by modeling body acceleration and adding low-cost markerless optical position sensors. A method based on a combination of the 3D rigid body kinematic equations and Denavit-Hartenberg (DH) convention is used to model body acceleration. Using this model, body acceleration measurements of the accelerometer are utilized to increase linearization order and compensate for body acceleration perturbations. To correct for the sensor-to-segment misalignment of the inertial sensors, position measurements of a low-cost markerless position sensor are used. Joint angles are estimated by Extended Kalman Filter (EKF) and compared with Unscented Kalman Filter (UKF) in terms of performance. Simulations are performed to quantify the existing error and potential improvements achievable by the proposed method. Experiments on a human test subject performing an upper limb rehabilitation task is used to validate the simulation results in realistic conditions. [ABSTRACT FROM AUTHOR]

The paper investigates a non-fragile robust control strategy for a half-car active suspension system considering human-body dynamics. A 4-DoF uncertain vibration model of the driver's body is combined with the car's model in order to make the controller design procedure more accurate. The desired controller is obtained by solving a linear matrix inequality formulation. Then the performance of the active suspension system with the designed controller is compared to the passive one in both frequency and time domain simulations. Finally, the effect of the controller gain variations on the closed-loop system performance is investigated numerically. [ABSTRACT FROM AUTHOR]

Unsteady pulsatile flow of blood through a porous-saturated, tapered and overlapping stenotic artery in the presence of magnetic field is examined theoretically and computationally. The power law constitutive model is employed to simulate hameo-rheological characteristics. The governing equation is derived assuming the flow to be unsteady, laminar, uni-directional and one-dimensional (1D). A robust, finite difference method is employed for the solution of the governing equation, subject to appropriate boundary conditions. Based on this solution, an extensive quantitative analysis is performed to analyze the effects of blood rheology, body acceleration, magnetohydrodynamic parameter, permeability parameter and arterial geometrical parameters of stenosis on various quantities of interest such as axial velocity, flow rate, resistance impedance and wall shear stress. The computations demonstrate that velocity, flow rate and shear stress increase while resistance to flow decreases with greater permeability parameter. Additionally, the effects of magnetic field are observed to be converse to those of permeability i.e., flow is decelerated and resistance is increased, demonstrating the powerful utility of exploiting magnetic fields in hemodynamic flow control (e.g., intra-corporeal surgical procedures). Furthermore, the size of trapped bolus of fluid is also found to be reduced for large values of the permeability parameter indicating that progressively more porous media circumvent bolus growth. [ABSTRACT FROM AUTHOR]

Mathematical model for the pulsatile blood flow through a porous medium under the influence of periodic body acceleration for gravity flow along an inclined tube by considering blood as a couple stress, incompressible and electrically conducting fluid in the presence of magnetic field has been investigated. Analytical expressions for axial velocity, flow rate, fluid acceleration and shear stress are obtained by applying the Laplace and finite Hankel's transforms. The velocity profiles for various values of Hartmann number, couple stress parameters and the angle of inclination are shown graphically. Also the effects of body acceleration, Womerseley parameters and permeability parameters have been discussed. The results obtained in the present mathematical model for different values of the parameters involved in the problem show that the flow of blood is influenced by the effect of magnetic field, the porous medium and the inclination angle. The present model is compared with the other existing models. Through this theoretical investigation, the applications of magnetic field have also been indicated in the field of biological, biomedical and engineering sciences. [ABSTRACT FROM AUTHOR]

Magnetohydrodynamic (MHD) flow of blood has been studied under the influence of body acceleration. With the help of Laplace and finite Hankel transforms, an exact solution is obtained for the unsteady flow of blood as an electrical conducting, incompressible and elastico-viscous fluid in the presence of a magnetic field acting along the radius of the pipe. Analytical expressions for axial velocity, fluid acceleration and flow rate has been obtained.

The pulsatile flow of blood in narrow arteries with multiple-stenoses under body acceleration is analyzed mathematically, treating blood as (i) single-phase Herschel-Bulkley fluid model and (ii) two-phase Herschel- Bulkley fluid model. The expressions for various flow quantities obtained by Sankar and Ismail (2010) for single-phase Herschel-Bulkley fluid model and Sankar (2010c) for two-phase Herschel-Bulkley fluid model are used to compute the data for comparing these fluid models in a new flow geometry. It is noted that the plug core radius, wall shear stress and longitudinal impedance to flow are marginally lower for two-phase HB fluid model than those of the single-phase H-B fluid model. It is found that the velocity decreases significantly with the increase yield stress of the fluid and the reverse behavior is noticed for longitudinal impedance to flow. It is also noticed that the velocity distribution and flow rate are higher for two-phase Herschel-Bulkley fluid model than those of the single-phase Herschel-Bulkley fluid model. It is also recorded that the estimates of the mean velocity increase with the increase of the body acceleration and this behavior is reversed when the stenosis depth increases. [ABSTRACT FROM AUTHOR]