The response of a twolayer viscoelastic coating to pressure disturbances from a turbulent boundary layer
Abstract
The main analytical result of an investigation of the twodimensional dynamic response of the interface between a compliant wall and a turbulent boundary layer flow is the equation of that interface displacement presented in the form of a Fourier inversion integral that must be numerically evaluated. The mathematical model, which uses a fixed disturbance pressure and includes the induced effects of the flow, permits the calculation of the initial energy transfer rate between the disturbance and the interfacial wave system. Analysis of the dispersion relations, a function of the boundary condition coefficients, for elemental plane waves that propagate along the flow/coating interface leads to the design of coatings with maximum response to boundary layer pressure fluctuations. For a singlelayer coating it was found that the shear wave speed of the coating should be between 0.40 to 0.83 times the outer flow and that the coating thickness should be about 0.22 to 1.0 times the boundary layer thickness for maximum surface displacements.
 Publication:

AIAA, Aerospace Sciences Meeting
 Pub Date:
 January 1984
 Bibcode:
 1984aiaa.meetX....D
 Keywords:

 Coatings;
 Pressure Pulses;
 Turbulent Boundary Layer;
 Viscoelasticity;
 Boundary Conditions;
 Boundary Layer Flow;
 Displacement;
 Fourier Transformation;
 Propagation Velocity;
 Surface Waves;
 Fluid Mechanics and Heat Transfer