  This paper presents a novel derivation of the perturbed convective wave
equation by utilizing the instantaneous velocity field as the foundation for
the convective operator. This approach holds particular significance in the
context of modeling fluid-structure-acoustic interaction (FSAI) problems, such
as those encountered in human phonation or systems involving fans with flexible
blades. The derivation is explored through two distinct methodologies: one
commencing from the linearized perturbed compressible equations (LPCE) and the
other rooted in the acoustic perturbation equations of variant 2 (APE-2). The
comparative analysis of these alternative derivations may contribute to a more
profound understanding of the underlying physics involved in FSI scenarios and
aeroacoustics.

Fluid Dynamics