SIMPLE WAVES AND SHOCKS IN THE SHALLOW 2-LAYER FLUID

The two-layer fluid is considered in the shallow-water approximation. Vertical integration of the spatially three-dimensional, scaled Euler equations yields a spatially two-dimensional, Galilei-invariant system. Diagnostic relations appear formally as the thermodynamics of a two-component, nonideal gas. Certain aspects of the theory are reminiscent of the hydrodynamics of superfluid helium. Nonlinear wave dynamics can be studied analytically: simple waves and shocks are discussed in detail. © 1990 The American Physical Society.