  The entropy conservative/stable algorithm of Friedrich~\etal (2018) for
hyperbolic conservation laws on nonconforming p-refined/coarsened Cartesian
grids, is extended to curvilinear grids for the compressible Euler equations.
The primary focus is on constructing appropriate coupling procedures across the
curvilinear nonconforming interfaces. A simple and flexible approach is
proposed that uses interpolation operators from one element to the other. On
the element faces, the analytic metrics are used to construct coupling terms,
while metric terms in the volume are approximated to satisfy a discretization
of the geometric conservation laws. The resulting scheme is entropy
conservative/stable, elementwise conservative, and freestream preserving. The
accuracy and stability properties of the resulting numerical algorithm are
shown to be comparable to those of the original conforming scheme (~p+1
convergence) in the context of the isentropic Euler vortex and the inviscid
Taylor-Green vortex problems on manufactured high order grids.
