International Journal of Computational Engineering Research||Vol, 04||Issue, 2|| ||Issn 2250-3005 || ||February||2014|| Page 20 Effect of Chemical Reaction on Mass Transfer over a Stretching Surface Embedded In a Porous Medium 1, E. M. A. Elbashbeshy , 2, A. M. Sedki 1 ,Mathematics Department, Faculty of science, Ain Shams University, Abbassia, Cairo, Egypt, 2, Mathematics Department, Faculty of science Jazan University, Jazan, KSA I. INTRODUCTION The boundary layer flows due to stretching surface in porous medium are relevant to many engineering problems such as paper production, preparing plastic and metal sheets etc.The dynamics of the boundary layer flow over a stretching surface originated from the pioneering work of Sakiadis [1, 2] who initiated the study of boundary layer flow over a continuous solid surface moving with constant speed. Crane [3] extended it to analyze the steady two dimensional boundary layer flow caused by the stretching of elastic flat surface which moves in its plane with velocity varying linearly with distance from a fixed point. Many authors presented some mathematical results, and good amount of references can be found in the papers by Ali [4] and [5], Elbashbeshy [6], Ishak et al. [7] and Elbashbeshy and Bazid [8] .The studies carried out in these papers in the case steady state flow. The unsteady state problem over a stretching surface, which is stretched with a velocity that depends on time is considered by Anderson et al. [9], Elbashbeshy and Bazid [10] and Ishak et al. [11]. The effects of chemically reactive solute distribution on fluid flow due to a stretching surface also bear equal importance in engineering researches. The chemical reaction effects were studied by many researchers on several physical aspects. The diffusion of a chemically reactive species in a laminar boundary layer flow over a flat plate was demonstrated by Chambre and Young [12]. The effect of transfer of chemically reactive species in the laminar flow over a stretching sheet explained by Andersson et al . [13]. Takhar et al. [14] analyzed the flow and mass transfer on a stretching sheet with a magnetic field and chemically reactive species with n-th order reaction. The mass transfer in boundary layer flow due to a stretching surface in porous medium also has important applications in many industrial problems. The effect of mass transfer in laminar flow over a stretching surface was investigated by Radwan and Elbashbeshy [15]. Radwan and Elbashbeshy [15] analyzed the flow and mass transfer on a stretching surface with a magnetic field. Akyildiz et al. [16] reported a solution for diffusion of chemically reactive species in a flow of a non- Newtonian fluid over a stretching sheet immersed in a porous medium. El-Aziz [17] explained unsteady flow due to a stretching sheet with mass and heat transfer. Recently, Krishnendu [18] studied the boundary layer flow with first order chemical reaction over a porous flat plate. Krishnendu [19] studied the mass transfer on a continuous flat plate moving in a parallel or reversely to a free stream in the presence of a chemical reaction. Ferdows et al. [20] investigated the effects of order of chemical reaction on mass transfer over a linearly stretching surface. Based on the above- mentioned investigations and applications, this paper is concerned with two-dimensional steady, incompressible, laminar boundary layer flow of a fluid over a linearly stretching surface. In this paper we investigate numerically the effects of chemical reaction on the steady laminar two- dimensional boundary layer flow and mass transfer over a stretching surface embedded in porous medium. The method of solutions based on the well-known similarity analysis together with shooting method. ABSTRACT An analysis is made to investigate the mass transfer over a stretching surface embedded in a porous medium in the presence of first order chemical reaction. Using similarity transformation, the governing partial differential equations are transformed into a set of ordinary differential equations which solved by shooting method. Comparisons with previously published work on special cases of the problem are performed and the results are found to be in excellent agreement. It is observed that the local mass transfer and concentration profile are very sensitive to change in the values of reaction rate parameter, permeability parameter and Schmidt number. KEYWORDS: Mass transfer – Stretching surface – Porous medium- Chemical reaction.