Accession Number:

ADA218546

Title:

Evidence for Self-Refraction in a Convergence Zone: NPE (Nonlinear Progressive Wave Equation) Model Results

Descriptive Note:

Corporate Author:

NAVAL OCEAN RESEARCH AND DEVELOPMENT ACTIVITY STENNIS SPACE CENTER MS

Personal Author(s):

Report Date:

1989-08-01

Pagination or Media Count:

15.0

Abstract:

The nonlinear progressive wave equation NPE model was developed by the Naval Ocean Research and Development Activity during 1982-1987 to study nonlinear effects in long-range oceanic propagation of finite amplitude acoustic waves, including weak shocks. The NPE model has been applied to propagation of a generic shock wave initial condition provided by Sandia Division 1533 in a few illustrative environments. The following consequences of nonlinearity are seen by comparing linear and nonlinear NPE results 1 a decrease in shock strength versus range a well-known result of entropy increases at the shock front 2 an increase in the convergence zone range and 3 a vertical meandering of the energy path about the corresponding linear ray path. Items 2 and 3 are manifestations of self-refraction. Keywords Wave propagation, ShockMechanics, Acoustic waves, Shock waves, Acoustic refraction, Nonlinear propagation, Shock focusing, Convergence zones.

Subject Categories:

  • Numerical Mathematics
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE