www.tjprc.org SCOPUS Indexed Journal editor@tjprc.org TWO-DIMENSIONAL SIMULATION TO INVESTIGATE THE INTERACTION OF FLUID - STRUCTURE INSIDE A MICROCHANNEL WITH ELASTIC AND RIGID BOUNDARY AS’AD ALIZADEH 1* & ANAS ABID MATTIE 2 1 Department of Mechanical Engineering, College of Engineering, University of Zakho, Zakho City, Iraq 2 Department of Mechanics, Duhok Polytechnic University, Duhok, Kurdistan Region, Iraq ABSTRACT In this paper, shape change of the elastic and rigid boundary in a micro-channel is simulated. The rings are considered as elastic boundaries immersed in the fluid flow. In this study, we use the Immersed Interface Method to simulate the flow around rigid objects and movement of the flexible objects. In this method, there is no compulsion to match the object mesh and the flow mesh. The results were found to be in good agreement with available data. First, the simultaneous motion of multiple membranes in a micro-channel and their interaction with each other and with flow are evaluated. In addition, simultaneous presence of multiple membranes would result in a reduction in the flow velocity. Finally, the effects of changes in the elastics and bending moduli on the deformation of cell are considered. KEYWORDS: Elastic Ring, Immersed Interface Method, Interaction & Deformation Received: Apr 29, 2018; Accepted: May 19, 2019; Published: Jul 19, 2019; Paper Id.: IJMPERDAUG2019119 INTRODUCTION The immersed interface method (IIM) is the most appropriate approach for solving the problem of fluid-solid interaction. The basis of IIM is to add a forcing term as a source term to the Navier-Stokes [1]. Feng and Michaelides [2] were the first to IIM and simulated suspensions of rigid disks in 2D. Le and Zhang [3] used in their work a hybrid LBM- IIM and noticed that the computed velocity profiles can deviate greatly from theoretical ones even for very simple flow situations, both in the immersed boundary layer and the bulk region. Dupuis et al. [4] studied how the coupling method of the forcing term between the Eulerian and Lagrangian grids could affect the results for the flow over an impulsively started cylinder at moderate Reynolds (Re) number. Wu and Shu [5] proposed a new version of IIM, which could well consider the effect of external force on the momentum flux as well as the discrete lattice effect. JiSeok and SangHwan [6] presented a numerical scheme for fluid-structure interaction, especially for elastic structures. They employed a hybrid IIM using an improved direct forcing scheme for the fluid, and a finite element method with Euler beam elements for the elastic plate. Zhang et al. [7, 8] also used a combination of the IIM and the LBM to investigate the microscopic hemodynamic and hemorheological behaviors of discrete RBCs in shear flow. They noted that three-dimensional simulation of RBCs is required to attain accurate results. In the present work, first, the simultaneous motion of multiple membranes in a micro- channel and their interaction with each other and with flow are evaluated. Finally, the effects of changes in the elastics and bending moduli on the deformation of cell are considered. Original Article International Journal of Mechanical and Production Engineering Research and Development (IJMPERD) ISSN(P): 2249-6890; ISSN(E): 2249-8001 Vol. 9, Issue 4, Aug 2019, 1151-1156 © TJPRC Pvt. Ltd.