Accession Number : ADC004569

Title :   Numerical Experiments on Collapsing Wakes in a Stratified Ocean.

Descriptive Note : Memorandum rept.,


Personal Author(s) : Piacsek,S. A. ; Roberts,G. O.

Report Date : DEC 1975

Pagination or Media Count : 72

Abstract : Numerical results are presented on the collapse of the mixed region generated by turbulence in the wake of a submarine moving through the stratified ocean and on the internal wave generation and propagation and the surface signal produced. The computer program does not model the turbulence but simply assumes a mixing ratio as an initial condition. Interactions with surface processes, and possible detectability at the surface, are not discussed. Advanced numerical methods have led to an extremely efficient program, both for accuracy and for economy in time and storage. These methods include using nonuniform staggered computational meshes in both directions and using Newtonian damping (porosity) at the computational boundaries to avoid reflection of internal waves. Also the vorticity and stream function formulation was used, together with a semi-leapfrog angled derivative representation of the equations, staggered in time. This reduced to four the number of two-dimensional arrays required, and also reduced computer time by allowing a large-time-step without instability.

Descriptors :   (*Wake, Ocean waves), (*Internal waves, Numerical analysis), (*Computer programs, Hydrodynamics), Turbulent flow, Interactions, Two dimensional, Surface waves, Wave propagation, Horizontal orientation, Thermoclines, Sea states, Stratification

Subject Categories : Computer Programming and Software
      Undersea and Antisubmarine Warfare
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE