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An Immersed Boundary Method for Solving the Compressible Navier-Stokes Equations with Fluid-Structure Interaction

AMS Seminar Series

Speaker: Michael Barad, Computational Aerosciences Branch, NASA Ames Research Center

Presentation

Seminar Slide Deck (PDF-9.7MB)

Abstract

An immersed boundary method for the compressible Navier-Stokes equation and the additional infrastructure that is needed to solve moving boundary and fully coupled fluid-structure interaction problems is described. All the methods described in this work were implemented in NASA's Launch Ascent and Vehicle Aerodynamics (LAVA) solver framework. The underlying immersed boundary method is based on the locally stabilized immersed boundary method that was previously introduced by the authors. In the present work this method is extended to account for all aspects that are involved for fluid-structure interaction simulations, such as fast geometry queries and stencil computations, the treatment of freshly cleared cells, and the coupling of the computational fluid dynamics solver with a linear structural finite element method. The current approach is validated for moving boundary problems with prescribed body motion and fully coupled fluid-structure interaction problems in 2D and 3D. As part of the validation procedure, results from the second AIAA aeroelastic prediction workshop are also presented. The current work is regarded as a validation study, while more advanced methods for fluid-structure interaction are currently being investigated, such as geometric and material nonlinearities, and advanced coupling approaches.

Biography

Michael Barad is a research scientist in the Computational Aerosciences Branch at NASA Ames Research Center. Mike received his B.S. from CU-Boulder in 1993, and his M.S. at UC Berkeley in 1997 focusing on computational environmental fluid mechanics. He received his Ph.D. at UC Davis in 2006, where his dissertation was "An Adaptive Cartesian Grid Projection Method for Environmental Flows." During his Ph.D. he was a DOE Computational Science Graduate Fellow, and through this he conducted his research within the Applied Numerical Algorithms Group at Lawrence Berkeley National Laboratory. From 2006-2009 he was at Stanford's Environmental Fluid Mechanics Laboratory as a NSF Mathematical Sciences Postdoctoral Research Fellow. There he continued to focus on structured adaptive mesh refinement (AMR) algorithms, and applied them to simulating multiscale nonlinear oceanic internal gravity waves. While at Stanford he also taught several graduate level courses. Mike then came to NASA Ames in 2009 and works with Cetin Kiris within the LAVA group where his focus is applications and numerical tools. In LAVA, he has developed a high-order high-performance immersed boundary code for solving unsteady Navier-Stokes equations using adaptively refined structured Cartesian grids, requiring only a water-tight surface triangulation. Using the LAVA solver he has worked on numerous NASA projects, including: the 21st century launch complex at KSC; SLS buffet analysis; NESC Battery simulations; Landing Gear Noise; SOFIA cavity acoustics; and many others. He has published in the Journal of Fluid Mechanics, Journal of Computational Physics, and others. Mike received the NASA Early Career Achievement Medal in 2014.