Experimental Framework Toward 2D Multiphysical Model Validation of Components Manufactured from Multifunctional, Degrading Material

Validation is a key component of model development; for models seeking to represent complex and coupled physics, comparison to carefully considered experimental assessments is necessary. In particular, models describing multifunctional materials, in this case materials designed to resist fluid flow and then dissolve, require validation cases that adequately represent the physics involved while inducing the desired material behavior. This paper seeks to develop a representative experiment for use in validating a two-dimensional model which examines the coupled physics of fluid dynamics, structural mechanics, and a changing reference outer mold line (OML) due to material loss. The proposed experiment examines a dissolvable baffle under flow in a water tunnel. The baffle spans the width of an open channel test section, minimizing 3D effects, and is made of water-soluble PVA. Two idealized cases affecting the structural response are studied: in one, a thick, "rigid" baffle is affixed to a torsional spring, and all structural response is assumed to be captured by spring rotation (theta); in the other case, a flexible baffle is fixed rigidly, and structural response is described via cantilevered beam bending. The OML changes, resulting from both deformation and material loss, the baffle experiences during the study are captured optically and analyzed via edge tracking. The expected fluid loads are approximated using measured flow velocity at a given point in the closed loop water tunnel. Observations of baffle profile and deformation in time under a constant flow condition are presented.