Estimation of pressure fluctuations in a turbulent boundary layer based on vibro-elastic models

摘要

A simple, but scientifically rigorous, framework is proposed for estimation of effectiveness of elastic materials for the reduction of pressure fluctuations. The framework employs the intrinsic correspondence between a transformation of vorticity perturbations into acoustic waves at the elastic boundary and the conversion of transverse (shear) waves to radiated longitudinal (pressure) waves. The case of a significantly subsonic wall flow (such as a turbulent boundary layer) is considered and the relative effect of elastic boundaries on the turbulent pressure fluctuations is estimated. The framework does not allow calculation of the absolute radiation levels, but is reasonably straightforward to implement in comparison to full-scale CFD and aero-elasticity models, and is not computationally intensive. The proposed approach enables rapid estimation of numerous 'what-if' scenarios that become important for design of new vibro-absorbing materials and for prototyping studies.