Turbularization of an acoustic boundary layer on a transpiring surface
Abstract
Turbularization of an acoustic boundarylayer (Stokes layer) on impermeable and permeable surfaces is analytically considered. The theoretical approach utilizes a secondorder closure model of turbulence. Both an approximate, closedform solution and a more comprehensive finite difference solution of the time dependent, parabolic, onedimensional governing equations are obtained. For simple acoustic boundarylayers on impermeable surfaces, both the approximate solution and the numerical results for the critical acoustic Mach number required for turbulent transiton are qualitatively confirmed by experiment. The calculations for acoustic boundarylayers with transpiration (injection) indicate a substantial reduction of the acoustic Mach number required for transition, up to a limiting injection velocity that is frequency dependent. The results may provide a mechanism for flowrelated combustion instablity in practical systems, particulary solid propellant rockets, since turbularization of the nearsurface combustion zone could result at relatively low acoustic Mach numbers
 Publication:

22nd Joint Propulsion Conference
 Pub Date:
 June 1986
 Bibcode:
 1986jpha.confQ....B
 Keywords:

 Acoustic Instability;
 Aeroacoustics;
 Solid Propellant Rocket Engines;
 Transpiration;
 Turbulent Boundary Layer;
 Computational Fluid Dynamics;
 Laminar Boundary Layer;
 NavierStokes Equation;
 Velocity Distribution;
 Fluid Mechanics and Heat Transfer