Verification of an Overset-grid Enabled Fluid-structure Interaction Solver
Open Access
- Author:
- Elsworth, Cooper W
- Graduate Program:
- Engineering Science and Mechanics
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- July 15, 2014
- Committee Members:
- Jonathan S Pitt, Thesis Advisor/Co-Advisor
Scott Miller, Thesis Advisor/Co-Advisor - Keywords:
- Fluid-Structure Interaction
Verification
Method of Manufactured Solutions
Overset
Finite Volume
Finite Element - Abstract:
- Coupled systems occur when two domains governed by dissimilar physics interact dynamically, resulting in strong two-way coupling between the domains. Research into these systems has become increasingly prevalent due to the wide variety of physical examples that exhibit these characteristics, as well as recent advancements in computational capability and parallelism. A notable example of coupled systems occurs in fluid-structure interaction (FSI), in which a deformable solid is surrounded by and/or immersed in a fluid. These systems exhibit strong, two-way coupling between the fluid and solid domains that require the development of expanded computational methods to solve. While current methods have provided the basis for the solution of these types of problems, optimizations are needed to solve realistic FSI problems. Existing overset mesh technology has been incorporated into an ALE based Fluid-Structure Interaction (FSI) code, producing a novel approach for investigating fully-coupled FSI phenomena. In particular, the Suggar++/DiRTlib overset mesh technology has been implemented into a partitioned FSI solver based on OpenFOAM and an in-house structural code. The impetus of this solver has been to address some of the problems that occur in complex FSI simulations, most notably concerns with the mesh motion experienced in large deformation cases. The overset solver intends to simplify mesh generation, maintain mesh quality throughout the simulation, and provide similar performance to current approaches. This thesis provides verification of the overset FSI solver and presents the effects of overset methods on FSI simulations. Verification is presented through the method of manufactured solutions on the disparate solver components and mesh refinement studies are performed on the coupled code. The method of manufactured solutions provides rigorous code verification, with error magnitudes and solver convergence rates determined for the separate solver components. Discussion of the challenges experienced in the establishment of a unified manufactured solution for partitioned FSI algorithms is also presented. The disparate solvers used in this work are found to exhibit the expected orders of convergence, verifying the correct implementation of the governing equations in these domains. A mesh refinement study with Richardson extrapolation further confirms the monotonic convergence of the FSI solution, and provides insight into the order of accuracy of the coupled solver. Use of the Turek and Hron benchmark case facilitates a consistent comparison of the proposed solver to current FSI methods and performance. Simulation data is presented, while investigations into the benefits of overset methods for FSI simulations is discussed. In addition, the relative performance of the solver is presented, in order to address the viability of the proposed solver's application.