Far Field Boundary Conditions for Underwater Explosions

Abstract

This work investigates a far field boundary condition (FFBC) designed to suppress the reflection of shocks and other waves from the outer computational boundaries. The general form of this condition is based on characteristic analysis and is based on a nonreflecting formulation in conjunction with an asymptotic analysis. The FFBC has been implemented in the DYSMAS code and applied to underwater explosion problems; both the short-term shock phase and the long-term bubble pulse problems are considered. Excellent results were obtained for shock problems in 1, 2, and 3 dimensions. The performance of these boundary conditions were mixed for the bubble pulse application with best results being obtained for relatively short periods, deep explosions, computed in multiple dimensions. It is concluded that the maximum mesh reduction in the bubble case is achieved when the far field boundary conditions are used in conjunction with a stretched mesh.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Dec 22, 1994
Accession Number
ADA477091

Entities

People

  • A. B. Wardlaw

Organizations

  • Naval Surface Warfare Center

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundaries
  • Cartesian Coordinates
  • Cauchy Problem
  • Computations
  • Engineering
  • Equations
  • Explosion Bubbles
  • Explosions
  • Explosives
  • Far Field
  • Mechanical Engineering
  • Mesh
  • Military Research
  • Surface Warfare
  • Three Dimensional
  • Two Dimensional
  • Underwater Explosions

Fields of Study

  • Physics

Readers

  • Coastal Oceanography
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Seismology