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The paper presents a method for simulating the flow of a viscous compressible gas around a moving obstacle, specified by the immersed boundary method on a simply connected unstructured mesh, and the features of its application for bodies of different configuration. An advantage of the developed moving-mesh method is that it keeps the topology of an initial mesh and provides an anisotropic mesh refinement to the 'immersed' surface of a streamlined body. The position and shape of the body are determined by the interpolation grid, which stores the distance and normal to the body surface. The paper also describes a special technique to improve the efficiency of adaptation. The technique is based on the prediction of the body location in some automatically chosen time. This trick allows to find the coordinates of mesh vertices during the predicted time interval by interpolation. The integral strategy combining the immersed boundary method with the developed moving-mesh adaptation is tested on several model cases in twoand three-dimensional formulations. However, the paper does not consider the numerical results of the cases, it is mostly targeted at the meshing details.

Abstract

A 3D fluid-structure interaction (FSI) code is under development. The fluid domain (Navier-Stokes) solver will employ a sharp interface ghost node immersed boundary method (IBM) to apply the boundary conditions at fluid-solid interfaces. The Navier-Stokes (N-S) solver has been verified using a classic Poiseuille channel flow. The current version of the immersed boundary method is being tested by solving a heat conduction problem. The order of accuracy of the IBM was shown to be just above second order.

Abstract

This work implements and analyses an Immersed Boundary Method based on Volume Pezalization for the flow simulator Airbus-CODA (CFD for ONERA, DLR, and AIRBUS). The Immersed Boundary Volume Penalization has unique advantages, e.g. easy to implement, straightforward formulation for moving geometries, and numerical errors can be controlled apriori [1, 2], showing the potential for aeronautical applications. Numerical experiments will assess the accuracy of the Immersed Boundary Volume Penalization in CODA.

Abstract

The immersed boundary method has attracted growing interest in CFD research community due to its simplicity in dealing with moving boundaries. In the diffused interface immersed boundary method, a discrete delta function is introduced to account for the boundary effects on the fluid, which causes the diffusion of the boundary interface. Therefore, the diffused interface immersed boundary method requires higher grid resolution in the vicinity of the immersed boundaries to get a better representation of the boundary. A strategy for the application of diffused interface immersed boundary-lattice Boltzmann method is introduced in the simulation of stenosis. The developed numerical method has been examined in the simulation of stenosis. Results show that the current solver is able to accurately predict the velocity profile within the stenosis.