  We outline the methodology of implementing moving boundary conditions into
the moving-mesh code MANGA. The motion of our boundaries is reactive to
hydrodynamic and gravitational forces. We discuss the hydrodynamics of a moving
boundary as well as the modifications to our hydrodynamic and gravity solvers.
Appropriate initial conditions to accurately produce a boundary of arbitrary
shape are also discussed. Our code is applied to several test cases, including
a Sod shock tube, a Sedov-Taylor blast wave and a supersonic wind on a sphere.
We show the convergence of conserved quantities in our simulations. We
demonstrate the use of moving boundaries in astrophysical settings by
simulating a common envelope phase in a binary system, in which the companion
object is modeled by a spherical boundary. We conclude that our methodology is
suitable to simulate astrophysical systems using moving and reactive boundary
conditions.
