C. Byun, A.L. Huizenga, H. Neeman, A.G. Stritz, G.P. Guruswamy

Understanding the transonic buffet condition during launch is of vital importance for a launch vehicle to survive the critical high-load early launch phase and, thus, to be able to accomplish its mission. However, this severe aeroelastic flight condition can only be modeled accurately when using computational solution modules that analyze the associated transient fluid/structure interaction using high-fidelity CFD/CSD methods. To analyze such atmospheric launch conditions, a software system was cost effectively built by using the current NASA CFD code HiMAP and enhancing its capabilities. HiMAP is an efficient super modular process to model and analyze the aeroelastic behavior of aerospace vehicles using high-fidelity flow equations such as the Euler or Navier-Stokes equations. Here, the creation of a dynamic transient structural sub-domain analysis capability was necessitated. The ensuing Computational Structural Dynamics (CSD) software module utilizes 9-degree-of-freedom triangular finite elements and a consistent mass matrix for dynamic transient analysis. A post-processing routine was added for the computation of the stress distributions in the structural model. To ensure compatibility and efficiency, the CSD module was written as a plug-in to the CFD code to provide accurate fluid-structure interaction analysis. The existing CFD grid set-up was used for flow analysis in HiMAP and also the present fluid-structure interface in the CFD code. For further efficiency improvements, the CSD module allows for parallel processing via MPI. Most CFD/CSD based transient aeroelastic simulation uses extensive CPU time. Thus, it is essential that it be cost-effectively run on closely coupled cluster computers. Here, we utilized computational resources in the form of commodity PC and/or workstation clusters. Specifically, the newly developed code was ported to a Linux based High Performance Computer at the OU Supercomputing Center for Education and Research (OSCER) of the University of Oklahoma - an Aspen Linux cluster with 270 Pentium4 XeonDP processors - and is expected to be installed on Columbia at NASA Ames Research Center. We are in the process of testing the performance of the new aeroelastic code by running high-fidelity computations of the fluid-structure interaction on four simple configurations, representing typical vertical launch vehicle models: bodies of revolution in the form of a hemispherecylinder, a cone-cylinder, a blunted cone-cylinder, and an ogive-cylinder.

International Forum on Aeroelasticity and Structural Dynamics, 2005, München

Conference Paper

englisch

21,0 x 29,7 cm, 11 Seiten

DGLR-Bericht, 2005, 2005-04, International Forum on Aeroelasticity and Structural Dynamics 2005; S.1-11; 2005; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

in getr. Zählung;

aeroelasticity, computational fluid dynamics, launch vehicles, computational structural dynamics

Bibliothek

2005