  We address semigroup well-posedness for a linear, compressible viscous fluid
interacting at its boundary with an elastic plate. We derive the model by
linearizing the compressible Navier-Stokes equations about an arbitrary flow
state, so the fluid PDE includes an ambient flow profile $\mathbf{U}$. In
contrast to model in [Avalos, Geredeli, Webster, 2017], we track the effect of
this term at the flow-structure interface, yielding a velocity matching
condition involving the material derivative of the structure; this destroys the
dissipative nature of the coupling of the dynamics. We adopt here a
Lumer-Phillips approach, with a view of associating fluid-structure solutions
with a $C_{0}$-semigroup $\left\{e^{\mathcal{A}t}\right\} _{t\geq 0}$ on a
chosen finite energy space of data. Given this approach, the challenge becomes
establishing the maximal dissipativity of an operator $\mathcal{A}$, yielding
the flow-structure dynamics.
