Effects of Turbulence on Stationary and Nonstationary Processes in C- Systems
Abstract
Turbularization of an acoustic boundary-layer (Strokes layer) on impermeable and permeable surfaces is analytically considered. The theoretical approach utilizes a second-order closure model of turbulence. An approximate, closed form solution and a more comprehensive finite difference solution of the time dependent, parabolic, one dimensional governing equations are obtained. For simple acoustic boundary layers on impermeable surfaces, the approximate solution and the numerical results for the critical acoustic Mach number required for turbulent transition are qualitatively confirmed. Calculations for acoustic boundary-layers with transpiration (injection) indicate a substantial reduction for the acoustic Mach number required for transition, up to a frequency dependent limiting injection velocity. The results may provide a practical mechanism for flow related combustion instability in solid propellent rockets, since turbularization of near surface combustion zone could result in relatively low acoustic Mach numbers. An analysis of the transitional and turbulent reactive acoustic boundary layer on a homogenous solid propellant surface investigates potential mechanisms of combustion instability. A new technique is developed for the condensed phase thermal layer, in which the propellant space is mapped onto the gas space and efficiently solved using the same adaptive numerical grid. An acoustic pressure node is obtained in the absence of a mean axial flow.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 23, 1990
- Accession Number
- ADA227067
Entities
People
- Robert A. Beddini
- Ted A. Roberts
Organizations
- University of Illinois Urbana–Champaign