Simulation of Multiphase Phenomena to Enhance Warhead Design

Abstract

Modeling fluid-structure interactions and body shape changes in high speed, compressible flow regimes is very challenging and still far from complete. For example, all the past studies were done for inviscid flows and studies on viscous flows over deforming bodies are scarce. High order accuracy is also difficult to achieve. When turbulence has to be captured in such complex flows, grid quality and subgrid closures have to be assessed for validity and applicability. Additional areas of interest are in predicting multi-phase blast explosives (MBX) where the energetic material may be heterogeneous (containing reactive particles) and generalized equations of state, thermodynamics and transport properties, and chemical kinetics are all required. In this study we propose to extend our advanced simulation code LESLIE to address these challenges by using a hybrid multi-scale method that combines an high order viscous Adaptive Cartesian Cut-cell with a multi-phase solver that can simulate both condensed phase and gas phase combustion. The parallel solver employs block-structured Adaptive Mesh Refinement (AMR) to resolve fine scale flow and surface features and a high-order level-set based tracking is used to resolve both moving and deforming embedded surfaces. To achieve good accuracy near deforming walls a higher order K-exact polynomial reconstruction is used to achieve till third-order spatial accuracy even in highly viscous regions. Since problems of interest also falls in hypersonic regime, compressible flow features such as shocks and expansions can be present and are needed to be handled by the solver. A hybrid approach is used wherein a second order upwind scheme is employed in regions with flow discontinuities and higher-order central scheme in smooth flow regions. Preliminary results show that this solver is capable of capturing all the key physics of interest. There are, however, more changes and features that need to be implemented and validated – these are proposed in this effort. Canonical and application test cases will be used to systematically develop and validate the new features and to understand the nature of flow physics in these complex and hitherto unresolved problems in unsteady fluid-structure interactions.

Document Details

Document Type
DoD Grant Award
Publication Date
Mar 01, 2016
Source ID
FA86511510007

Entities

People

  • Suresh Menon

Organizations

  • Air Force Research Laboratory
  • Georgia Tech Research Corporation
  • United States Air Force

Tags

Fields of Study

  • Physics

Readers

  • Computational Fluid Dynamics (CFD)

Technology Areas

  • Hypersonics
  • Hypersonics - Hypersonic Flight