INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS Int. J. Numer. Meth. Fluids (2010) Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/fld.2438 Numerical simulation of mass transfer to micropolar fluid flow past a stenosed artery Md. A. Ikbal 1 , S. Chakravarty 1 , Sarifuddin 2 and P. K. Mandal 1, ∗, † 1 Department of Mathematics, Visva-Bharati, Santiniketan 731235, West Bengal, India 2 Department of Mathematics, Raiganj Surendranath College, Raiganj, West Bengal, India SUMMARY A mathematical model of unsteady non-Newtonian blood flow together with the mass transfer through constricted arteries has been developed. The mass transport refers to the movement of atherogenic molecules, i.e. blood-borne components, such as low-density lipoproteins from flowing blood into the arterial walls or vice versa. 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 cosine-shaped stenosis in its lumen. The mass transfer to blood is controlled by the convection–diffusion equation. The governing equations of motion accompanied by the appropriate choice of the boundary conditions are solved numerically by Marker and Cell method and the results obtained are checked for numerical stability with the desired degree of accuracy. The quantitative analysis carried out finally includes the respective profiles of the flow-field and the mass concentration along with their distributions over the entire arterial segment as well. The key factors, such as the wall shear stress and Sherwood number, are also examined for further quantitative insight into the flow and the mass transport phenomena through arterial stenosis. The present results show consistency with several existing results in the literature which substantiate sufficiently to validate the applicability of the model under consideration. Copyright  2010 John Wiley & Sons, Ltd. Received 5 November 2009; Revised 11 June 2010; Accepted 18 August 2010 KEY WORDS: micropolar fluid; mass transfer; unsteady; MAC method; separation zones 1. INTRODUCTION Atherosclerosis is a common form of cardiovascular disease that primarily affects the blood vessels. One of the main characteristics of early atherosclerosis is the accumulation of low density lipoprotein (LDL) within the subendothelial layer of the arterial wall which causes flow disorder in the arteries. The development of stenosis in the arteries defends oxygen transport to the tissues and dependent organs. There are many studies based on the Newtonian model of flowing blood which is acceptable for high shear rate flow, that is, in the case of flow through large arteries [1–4]. But under diseased conditions, blood exhibits remarkable non-Newtonian properties. A theoretical study of a particle fluid suspension model applied to the problem of pulsatile blood flow through a circular tube under periodic body acceleration has been conducted by Usha and Prema [5] while the two-dimensional computational fluid dynamical simulation of steady and pulsatile laminar flow of Newtonian and non-Newtonian fluids over a backward facing step was performed by Choi and Barakat [6]. Khanafer et al. [7] indicated that the velocity fields were significantly influenced by ∗ Correspondence to: P. K. Mandal, Department of Mathematics, Visva-Bharati, Santiniketan 731 235, West Bengal, India. † E-mail: pkmind02@yahoo.co.uk Copyright  2010 John Wiley & Sons, Ltd.