Effect of periodic body acceleration and pulsatile pressure gradient pressure on non-Newtonian blood flow in arteries

2015 ◽  
Vol 38 (3) ◽  
pp. 703-708 ◽  
Author(s):  
S. Mosayebidorcheh ◽  
M. Hatami ◽  
T. Mosayebidorcheh ◽  
D. D. Ganji
Keyword(s):  
Blood Flow ◽  
Pressure Gradient ◽  
Body Acceleration ◽  
Pulsatile Pressure ◽  
Pulsatile Pressure Gradient

scholarly journals Study of Magnetohydrodynamic Pulsatile Blood Flow through an Inclined Porous Cylindrical Tube with Generalized Time-Nonlocal Shear Stress

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Nehad Ali Shah ◽  
A. Al-Zubaidi ◽  
S. Saleem
Keyword(s):  
Blood Flow ◽  
Pressure Gradient ◽  
Cylindrical Tube ◽  
Transverse Magnetic ◽  
Inverse Laplace Transform ◽  
Pulsatile Pressure ◽  
Significant Difference ◽  
Flow Through ◽  
Mathcad Software ◽  
Pulsatile Pressure Gradient

The effects of pulsatile pressure gradient in the presence of a transverse magnetic field on unsteady blood flow through an inclined tapered cylindrical tube of porous medium are discussed in this article. The fractional calculus technique is used to provide a mathematical model of blood flow with fractional derivatives. The solution of the governing equations is found using integral transformations (Laplace and finite Hankel transforms). For the semianalytical solution, the inverse Laplace transform is found by means of Stehfest’s and Tzou’s algorithms. The numerical calculations were performed by using Mathcad software. The flow is significantly affected by Hartmann number, inclination angle, fractional parameter, permeability parameter, and pulsatile pressure gradient frequency, according to the findings. It is deduced that there exists a significant difference in the velocity of the flow at higher time when the magnitude of Reynolds number is small and large.

NUMERICAL SIMULATION OF UNSTEADY TWO-LAYERED PULSATILE BLOOD FLOW IN A STENOSED FLEXIBLE ARTERY: EFFECT OF PERIPHERAL LAYER VISCOSITY

2005 ◽  
Vol 9 (2) ◽  
pp. 99-114 ◽  
Author(s):  
S. Chakravarty ◽  
P. K. Mandal ◽  
A. Mandal
Keyword(s):  
Blood Flow ◽  
Unsteady Flow ◽  
Pressure Gradient ◽  
Cylindrical Tube ◽  
Shear Stresses ◽  
Flow Mechanism ◽  
Moving Wall ◽  
Pulsatile Pressure ◽  
Pulsatile Pressure Gradient ◽  
Good Agreement

The present paper deals with a theoretical investigation of blood flow in an arterial segment in the presence of stenosis. The streaming blood is treated to be composed of two different layers ‐ the central core and the plasma. The former is considered to be non‐Newtonian liquid characterised by the Power law model, while the latter is chosen to be Newtonian. The artery is simulated as an elastic (moving wall) cylindrical tube. The unsteady flow mechanism of the present study is subjected to a pulsatile pressure gradient arising from the normal functioning of the heart. The time‐variant geometry of the stenosis has been accounted for in order to improve resemblance to the real situation. The unsteady flow mechanism, subjected to pulsatile pressure gradient, has been solved using finite difference scheme by exploiting the physically realistic prescribed conditions. An extensive quantitative analysis has been performed through numerical computations of the flow velocity, the flux, the resistive impedances and the wall shear stresses, together with their dependence with the time, the input pressure gradient and the severity of the stenosis, presented graphically at the end of the paper in order to illustrate the applicability of the model under consideration. Special emphasis has been made to compare the existing results with the present ones and found to have a good agreement. Straipsnyje nagrinejamas kraujo srauto tekejimas esant stenozei. Nagrinejamas dvisluoks‐nis kraujo tekejimas. Arterija modeliuojama kaip vamzdis su elastinemis sienelemis. Kraujo srauto nestacionaruma sukelia širdies veikla. Skaitinis sprendinys randamas baigtiniu skirtumu metodu. Atlikta kokybine skaitiniu sprendiniu analize iliustruojanti greičiu, srautu, sieneles itampu priklausomybe laike. Skaitiniai rezultatai pakankamai gerai patvirtina eksperimentinius duomenis.

scholarly journals Pulsating Flow of an Ostwald—De Waele Fluid between Parallel Plates

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 932
Author(s):  
Rodrigo González ◽  
Aldo Tamburrino ◽  
Andrea Vacca ◽  
Michele Iervolino
Keyword(s):  
Shear Stress ◽  
Analytical Solution ◽  
Wall Shear Stress ◽  
Pressure Gradient ◽  
Velocity Distribution ◽  
Momentum Equation ◽  
Parallel Plates ◽  
Analytical Computation ◽  
Pulsatile Pressure ◽  
Pulsatile Pressure Gradient

The flow between two parallel plates driven by a pulsatile pressure gradient was studied analytically with a second-order velocity expansion. The resulting velocity distribution was compared with a numerical solution of the momentum equation to validate the analytical solution, with excellent agreement between the two approaches. From the velocity distribution, the analytical computation of the discharge, wall shear stress, discharge, and dispersion enhancements were also computed. The influence on the solution of the dimensionless governing parameters and of the value of the rheological index was discussed.

Influence of streaming potential on pulsatile pressure-gradient driven flow through an annulus

2013 ◽  
Vol 34 (5) ◽  
pp. 691-699 ◽  
Author(s):  
Anish Shenoy ◽  
Jeevanjyoti Chakraborty ◽  
Suman Chakraborty
Keyword(s):  
Pressure Gradient ◽  
Streaming Potential ◽  
Pulsatile Pressure ◽  
Flow Through ◽  
Pulsatile Pressure Gradient

Microvascular pressure in venules of skeletal muscle during arterial pressure reduction

1986 ◽  
Vol 250 (5) ◽  
pp. H838-H845 ◽  
Author(s):  
S. D. House ◽  
P. C. Johnson
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Arterial Pressure ◽  
Pressure Gradient ◽  
Pressure Difference ◽  
Reactive Hyperemia ◽  
Sartorius Muscle ◽  
Pressure Reduction ◽  
Large Vein ◽  
The Difference

It has been suggested from whole organ studies that the viscosity of blood in skeletal muscle venules varies inversely with flow over physiological flow ranges. If this is the case, the hydrostatic pressure gradient in venules should change less than flow as flow is altered. To test this hypothesis, pressure in venules of cat sartorius muscle was measured during stepwise arterial pressure reduction to 20 mmHg. Large vein pressure remained constant at about 5 mmHg. Average pressures in the large venules (40–185 microns) ranged from 13.6 to 10.0 mmHg. The difference between pressure in these venules and large vein pressure fell in proportion to the reduction in blood pressure and blood flow. Pressures in the smallest venules studied (25 microns) averaged 19.7 +/- 6.2 (SD) mmHg. The pressure difference between the smallest venules and the large vein fell less than the arteriovenous pressure difference or blood flow when arterial pressure was reduced. During reactive hyperemia the pressure gradient between the smallest venules and the large vein rose proportionately less than blood flow. The stability of pressure in the smallest venules is consistent with the hypothesis that blood viscosity varies inversely with flow rate.

Antiadrenergic and Antihistaminic Therapy in Hemorrhagic Shock in Dog and Rat

1956 ◽  
Vol 186 (1) ◽  
pp. 79-84 ◽  
Author(s):  
S. Jacob ◽  
Edward W. Friedman ◽  
Sabin Levenson ◽  
Philip Glotzer ◽  
H. A. Frank ◽  
...  
Keyword(s):  
Blood Flow ◽  
Survival Rate ◽  
Blood Loss ◽  
Pressure Gradient ◽  
Protective Effect ◽  
Hemorrhagic Shock ◽  
Venous Pressure ◽  
Survival Period ◽  
Effect Of Treatment ◽  
Antihistaminic Drugs

The influence of pretreatment with dibenamine on the development and course of hemorrhagic shock, and the effect of treatment with dibenamine, rapidly acting antiadrenergic drugs, or antihistaminic drugs after hemorrhagic shock had been allowed to become unresponsive to replacement transfusion, were tested in dogs prepared in advance to permit measurement of portal-caval venous pressure gradient. Preliminary dibenamine administration was also tested in rats submitted to hemorrhagic shock. The conclusions were as follows: 1) The protective effect of dibenamine prior to the induction of hemorrhagic shock in the dog consists mainly of a reduction of the bleeding volume. Intrahepatic vasoconstriction is not reduced. A dog which is not under the influence of dibenamine can tolerate a greater degree of blood loss than a dibenaminized dog. After hemorrhagic shock has been allowed to become refractory to replacement transfusion, antiadrenergic and antihistaminic drugs do not reduce intrahepatic vasoconstriction or increase the survival period or the survival rate. 2) Dibenamine given prior to hemorrhage enables the rat to survive a degree of blood loss which is lethal to the untreated rat. This, in part, appears to be due to better blood flow to the respiratory center.

The effect of body acceleration on the dispersion of solute in a non-Newtonian blood flow through an artery

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nur Husnina Saadun ◽  
Nurul Aini Jaafar ◽  
Md Faisal Md Basir ◽  
Ali Anqi ◽  
Mohammad Reza Safaei
Keyword(s):  
Blood Flow ◽  
Boundary Conditions ◽  
Yield Stress ◽  
Solute Concentration ◽  
Casson Fluid ◽  
Blood Velocity ◽  
Content Type ◽  
Body Acceleration ◽  
Lead Angle ◽  
Flow Through

Purpose The purpose of this study is to solve convective diffusion equation analytically by considering appropriate boundary conditions and using the Taylor-Aris method to determine the solute concentration, the effective and relative axial diffusivities. Design/methodology/approach >An analysis has been conducted on how body acceleration affects the dispersion of a solute in blood flow, which is known as a Bingham fluid, within an artery. To solve the system of differential equations analytically while validating the target boundary conditions, the blood velocity is obtained. Findings The blood velocity is impacted by the presence of body acceleration, as well as the yield stress associated with Casson fluid and as such, the process of dispersing the solute is distracted. It graphically illustrates how the blood velocity and the process of solute dispersion are affected by various factors, including the amplitude and lead angle of body acceleration, the yield stress, the gradient of pressure and the Peclet number. Originality/value It is witnessed that the blood velocity, the solute concentration and also the effective and relative axial diffusivities experience a drop when either of the amplitude, lead angle or the yield stress rises.

Abstract 16856: Mathematical Modeling of Blood Flow to Evaluate the Hemodynamic Significance of Peripheral Vascular Lesions

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Seyed Mehran Mirramezani ◽  
Paul Cimadomo ◽  
Ernie Ahsan ◽  
David Shavelle ◽  
Leonardo Clavijo ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pressure Gradient ◽  
Ankle Brachial Index ◽  
Peripheral Arteries ◽  
Flow Modeling ◽  
Peripheral Vascular ◽  
Blood Flow Modeling ◽  
Resting Pressure ◽  
Grade Iii ◽  
Significant Lesion

Introduction: Evaluating the severity of lesions in peripheral arteries is challenging. Image-based blood flow modeling from peripheral computed tomographic angiography (pCTA) may provide a non-invasive method to determine the hemodynamic significance of lesions. The objective of this study was to evaluate the diagnostic performance of a trans-lesion pressure drop computed from pCTA-based blood flow modeling in the peripheral arteries. Methods: Ten patients undergoing digital subtraction angiography (DSA) and pCTA were included. The peripheral arteries were divided into 8 segments per extremity and stenosis severity was visually graded by DSA as non-stenosed (grade 0), mild (grade I), moderate (grade II), severe (grade III), occluded (grade IV) or non-evaluable. A functionally significant lesion was defined as grade III or IV by DSA. Independent from the DSA review, a resting pressure gradient (rPG) and exercise PG (ExPG) for each segment was calculated from pCTA-based blood flow modeling (Figure), and a functionally significant lesion was defined as having an rPG > 5 mm Hg or an ExPG > 20 mm Hg. Results: Mean age was 52±16 years, 4 patients (40%) were male, 8 patients (80%) presented with critical limb ischemia, mean ankle brachial index was 0.60±0.29 and 66 arterial segments were available for both assessment methods. Twenty-two segments had functionally significant lesions by DSA. For rPG, sensitivity was 80%, specificity was 85% and accuracy was 79% with DSA as the standard; for ExPG, sensitivity was 84%, specificity was 89% and accuracy was 88%. Conclusions: Use of a resting pressure gradient > 5 mm Hg and an exercise pressure gradient > 20 mm Hg measured by peripheral computed tomography-based blood flow modeling accurately identifies functionally significant stenosis in patients with advanced peripheral vascular disease. These results support a prospective imaging trial to further validate this novel approach.

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