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Uttar Dinajpur, India

Sarifuddin,Raiganj Surendranath College
Journal of Mechanics in Medicine and Biology | Year: 2014

The present investigation deals with a mathematical model representing the response of heat transfer to blood streaming through the arteries under stenotic condition. The flowing blood is represented as the suspension of all erythrocytes assumed to be Casson fluid and the arterial wall is considered to be rigid having differently shaped stenoses in its lumen arising from various types of abnormal growth or plaque formation. The governing equations of motion accompanied by the appropriate choice of the boundary conditions are solved numerically by Marker and Cell (MAC) method. The necessary checking for numerical stability has been incorporated into the algorithm for better precision of the results computed. The quantitative analysis carried out finally includes the respective profiles of the flow-field and the temperature along with their individual distributions over the entire arterial segment as well. The key factors like the pressure drop, wall shear stress, flow separation, Nusselt number and streamlines are examined for qualitative insight into the blood flow and heat transport phenomena through arterial stenosis. In conformity with other several existing findings the present simulation predicts that the pressure drop and Nusselt number diminishes with increasing yield stress values, and significant enhancement in values of Nusselt number is observed with increasing severity of the stenosis. However, the effect of the shapes of the stenoses on flow separation cannot be ruled out from the present investigation. © 2014 World Scientific Publishing Company. Source


Tan Y.B.,University of Technology Malaysia | Mustapha N.,University of Technology Malaysia | Sarifuddin,Raiganj Surendranath College
AIP Conference Proceedings | Year: 2014

Circulatory system in human body is built up by network of blood vessels which includes numerous bifurcations. This study presents the influences of bifurcation geometry under the effects of gravity and an irregular stenosis. Along the studied vessel, blood is treated as an incompressible Newtonian fluid. In this paper, an unsteady two-dimensional nonlinear model is developed, where significant gravity term are added to the governing equations. The selected numerical method for the problem is the Marker and Cell (MAC) method based on finite difference approximations. The governing equations are discretized to uniform staggered grids before developing the algorithm in Matlab software. Furthermore, successive-over-relaxation (S.O.R.) method is used to solve the Poisson equation of pressure. Then, pressure-velocity corrector is implied to improve accuracy of the results obtained. The results are presented graphically. © 2014 AIP Publishing LLC. Source


Sarifuddin,Raiganj Surendranath College | Chakravarty S.,Visva Bharati University | Mandal P.K.,Visva Bharati University
International Journal of Heat and Mass Transfer | Year: 2013

A mathematical model of unsteady non-Newtonian blood flow together with heat transfer through constricted arteries has been developed. The flowing blood is represented as the suspension of all erythrocytes assumed to be Eringen's micropolar fluid and the arterial wall is considered to be rigid having differently shaped stenoses in its lumen arising from various types of abnormal growth or plaque formation. The governing equations of motion accompanied by the appropriate choice of the initial and the boundary conditions are solved numerically by Marker and Cell (MAC) method and the results are checked for numerical stability with desired degree of accuracy. The quantitative analysis carried out finally includes the respective profiles of the flow-field and the temperature distribution over the entire arterial segment as well. The key factors like the wall shear stress, the stream lines, the separation- reattachment points, the pressure drop and the heat contours are also examined for further qualitative insight into the heat flow phenomena. Results show that the initiation of nonzero microspin velocity on the arterial wall prompts early flow separation and the occurrence of multiple separation zones may also be attributed due to the introduction of nonzero microspin boundary condition parameter S together with the rough valleys and ridges presented on the outline of the diverging part of the irregular stenosis. The present results also predict the excess pressure drop across the cosine stenoses than the irregular ones and show quite consistency with several existing results in the literature which substantiate sufficiently to validate the applicability of the model under consideration. © 2012 Elsevier Ltd. All rights reserved. Source


Sarifuddin,Raiganj Surendranath College
Chemical Engineering Communications | Year: 2012

A mathematical model of unsteady non-Newtonian blood flow in an artery under stenotic condition has been developed. The flowing blood is considered to be a viscoelastic fluid characterized by the Oldroyd-B model and the arterial wall is considered to be rigid, having cosine-shaped stenosis. The governing equations of motion accompanied by appropriate choice of the initial and boundary conditions are solved numerically by the MAC (marker and cell) method, and the results are checked, for numerical stability with desired degree of accuracy. The key factors like the wall shear stress, resistive impedance, and the other viscoelastic parameters are also examined for further qualitative insight into the flow through arterial stenosis. Comparison of the results reveals that dimensionless pressure drop for the viscoelastic model increases while it diminishes for the shear-thinning power law model over that of the Newtonian model. Moreover, the possibility of flow separation increases with increasing relaxation time (Deborah number), and in case of Newtonian fluid, delayed separation is observed. The grid independence study has also been performed successfully in order to validate the applicability of the methodology as well as the model used under consideration. Special emphasis has duly been made to compare the present theoretical results with the existing ones, and good agreement between them has been achieved both qualitatively and quantitatively. © Taylor & Francis Group, LLC. Source


Sarifuddin,Raiganj Surendranath College | Chakravarty S.,Visva Bharati University | Mandal P.K.,Visva Bharati University
Zeitschrift fur Angewandte Mathematik und Physik | Year: 2013

The present investigation deals with a mathematical model of blood flow through an asymmetric (about its narrowest point) arterial constriction obtained from casting of a mildly stenosed artery. The flowing blood is represented as the suspension of all red cells (erythrocytes) in plasma assumed to be Casson fluid, while the arterial wall is considered to be rigid having differently shaped stenoses in its lumen arising from various types of abnormal growth or plaque formation. The governing equations of motion accompanied by the appropriate choice of the boundary conditions are solved numerically by Marker and Cell method in order to compute the physiologically significant quantities with desired degree of accuracy. The necessary checking for numerical stability has been incorporated in the algorithm for better precision of the results computed. The quantitative analyses have been carried out finally with the inclusion of the respective profiles of the flow field over the entire arterial segment as well. The key factors such as the wall shear stress, the pressure drop and the velocity profiles are exhibited graphically and examined thoroughly for qualitative insight into blood flow phenomena through arterial stenosis. © 2013 Springer Basel. Source

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