Fluid Structure Interaction: Evaluation of two coupling techniques

Sammanfattning: This thesis concerns one of the upcoming and well discussed subjects withincalculations these days, namely how to perform an analysis of the interactionbetween fluid and structure, called FSI (Fluid Structure Interaction). In the report,evaluations of two different methods of simulating FSI are done. These are knownas Practical FSI (P-FSI) and Direct Coupled FSI (DC-FSI). The methods aredeveloped by Acusim in cooperation with Simulia and the softwares used areAbaqus and AcuSolve.The first part of the thesis is dedicated to explain the general theory and thegoverning equations for FSI. After the general explanation a more delimitatedexplanation regarding P-FSI and DC-FSI are given. After this we show how tosetup and perform the couplings regarding which parameters that need to bedefined and how to perform the analyses using Abaqus and AcuSolve.The last section of the thesis covers the evaluation process. We started withevaluating the methods against a benchmark problem where we compared thecalculation time and accuracy regarding displacements and frequencies. The nextthing we evaluated was how different numbers of modes used in the P-FSIcoupling affects the result. The last thing we evaluated was the robustness of themethods using different mass densities of the structure and different time-stepsizes.The result of the evaluation regarding the criteria: accuracy, calculation time androbustness showed that the P-FSI method is the most efficient method comparedto DC-FSI regarding FSI problems when the structural response is linear.