12 research outputs found
Spherically symmetric solutions to a model for phase transitions driven by configurational forces
We prove the global in time existence of spherically symmetric solutions to
an initial-boundary value problem for a system of partial differential
equations, which consists of the equations of linear elasticity and a
nonlinear, non-uniformly parabolic equation of second order. The problem models
the behavior in time of materials in which martensitic phase transitions,
driven by configurational forces, take place, and can be considered to be a
regularization of the corresponding sharp interface model. By assuming that the
solutions are spherically symmetric, we reduce the original multidimensional
problem to the one in one space dimension, then prove the existence of
spherically symmetric solutions. Our proof is valid due to the essential
feature that the reduced problem is one space dimensional.Comment: 25 page
Low Mach number limit for non-isentropic magnetohydrodynamic equations with ill-prepared data and zero magnetic diffusivity in bounded domains
In this article, we verify the low Mach number limit of strong solutions to
the non-isentropic compressible magnetohydrodynamic equations with zero
magnetic diffusivity and ill-prepared initial data in three-dimensional bounded
domains, when the density and the temperature vary around constant states.
Invoking a new weighted energy functional, we establish the uniform estimates
with respect to the Mach number, especially for the spatial derivatives of high
order. Due to the vorticity-slip boundary condition of the velocity, we
decompose the uniform estimates into the part for the fast variables and the
other one for the slow variables. In particular, the weighted estimates of
highest-order spatial derivatives of the fast variables are crucial for the
uniform bounds. Finally, the low Mach number limit is justified by the strong
convergence of the density and the temperature, the divergence-free component
of the velocity, and the weak convergence of other variables. The methods in
this paper can be applied to singular limits of general hydrodynamic equations
of hyperbolic-parabolic type, including the full Navier-Stokes equations