We consider 3D compressible isentropic Euler equations describing the motion
of a liquid in an unbounded initial domain with a moving boundary and a fixed
flat bottom at finite depth. The liquid is under the influence of gravity and
surface tension and it is not assumed to be irrotational. We prove the local
well-posedness by introducing carefully-designed approximate equations which
are asymptotically consistent with the a priori energy estimates. The energy
estimates yield no regularity loss and are uniform in Mach number. Also, they
are uniform in surface tension coefficient if the Rayleigh-Taylor sign
condition holds initially. We can thus simultaneously obtain incompressible and
vanishing-surface-tension limits. The method developed in this paper is a
unified and robust hyperbolic approach to free-boundary problems in
compressible Euler equations. It can be applied to some important complex fluid
models as it relies on neither parabolic regularization nor irrotational
assumption. This paper joined with our previous works [46,47] rigorously proves
the local well-posedness and the incompressible limit for a compressible
gravity water wave with or without surface tension.Comment: 63 page