Evidence for Self-Refraction in a Convergence Zone: NPE (Nonlinear Progressive Wave Equation) Model Results
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, Shock(Mechanics), Acoustic waves, Shock waves, Acoustic refraction, Nonlinear propagation, Shock focusing, Convergence zones.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1989
- Accession Number
- ADA218546
Entities
People
- B. E. Mcdonald
- Daniel R. Plante
Organizations
- United States Naval Research Laboratory