Force/Moment-Conserving Pressure Mapping Scheme for Fluid/Structure Interaction Analysis

Abstract

With the developments in computer-aided engineering, more complex and difficult simulations have become possible, and the demand for fluid/structure interaction (FSI) analysis has been increasing. Various approximation methods have been developed for pressure/load data mapping for FSI analysis. However, for most existing mapping algorithms, the sum of force/moment, which is one of the most important physical properties to be conserved, is not generally conserved. In this paper, we propose a new pressure mapping technique that is intuitive and easy to implement while algorithmically preserving force/moment for interfaces with complex and simple shapes. This technique distributes the pressure of the computational fluid dynamics (CFD) boundary mesh as concentrated loads to the nodes of the nearest structural element. The load distribution from each CFD cell is assumed to satisfy a plane equation, and the mapping loads are obtained by solving the equations to determine the coefficients of the plane equation. Furthermore, an algorithm to search for neighboring structural nodes for load mapping has been developed for various situations. To verify the proposed method, a simple plate model, pipe model with internal flow, and full-scale aircraft model were used. The results of the validation examples showed reliable load distributions and structural deformations with force/moment conservation.