  A computational technique has been developed to perform compressible flow
simulations involving moving boundaries using an embedded boundary approach
within the block-structured adaptive mesh refinement framework of AMReX. A
conservative, unsplit, cut-cell approach is utilized and a ghost-cell approach
is developed for computing the flux on the moving, embedded boundary faces.
Various test cases are performed to validate the method, and compared with
analytical, experimental, and other numerical results in literature. Inviscid
and viscous test cases are performed that span a wide regime of flow speeds $-$
acoustic (harmonically pulsating sphere), smooth flows (expansion fan created
by a receding piston) and flows with shocks (shock-cylinder interaction,
shock-wedge interaction, pitching NACA 0012 airfoil and shock-cone
interaction). A closed system with moving boundaries $-$ an oscillating piston
in a cylinder, showed that the percentage error in mass within the system
decreases with refinement, demonstrating the conservative nature of the moving
boundary algorithm. Viscous test cases involve that of a horizontally moving
cylinder at $Re=40$, an inline oscillating cylinder at $Re=100$, and a
transversely oscillating cylinder at $Re=185$. The judicious use of adaptive
mesh refinement with appropriate refinement criteria to capture the regions of
interest leads to well-resolved flow features, and good quantitative comparison
is observed with the results available in literature.
