Combustion wave instabilities in turbulent flows
Abstract
NavierStokes solutions are used to calculate oscillatory components of pressure, velocity, and density, which in turn provide necessary data to compute energy growth factors to determine combustion instability. It is shown that wave instabilities are associated with changes in entropy and the space and time averages of oscillatory components of pressure, velocity and density, together with the mean flow field in the energy equation. Compressible laminar and turbulent flows and reacting flows with hydrogen/oxygen combustion are considered in this paper. The space shuttle main engine combustion/thrust chamber is used for illustration of the theory. The analysis shows that the increase of mean pressure and disturbances consistently results in the increase in instability. It is shown that adequate combustion instability analysis requires at least third order nonlinearity in energy growth or decay.
 Publication:

Advances in Numerical Simulation of Turbulent Flows
 Pub Date:
 1991
 Bibcode:
 1991anst.proc...77Y
 Keywords:

 Combustion Stability;
 Flame Propagation;
 Isentropic Processes;
 Laminar Flow;
 Reacting Flow;
 Turbulent Flow;
 Combustion Chambers;
 Compressible Flow;
 Entropy;
 NavierStokes Equation;
 Space Shuttle Main Engine;
 Fluid Mechanics and Heat Transfer