Velocity Coupling Analysis.

The report describes an analytical approach relating to the role of velocity coupled combustion response in solid propellant combustion instability. A study of the fundamental interaction between acoustic velocities and the propellant combustion indicate that a basic law relating the pressure and velocity dependence of combustion can most practically be assumed to be multiplicative. An analysis of velocity coupling acoustics in a T-burner indicate that both the Hart-McClure approach as refined by Coates and the Culick approach should be considered in reducing experimental data until the apparent controversy is resolved. Threshold velocity and flow reversal effects have been incorporated into an existing motor analysis sample calculations indicate that an increased threshold velocity reduces the acoustic driving due to velocity coupling and that the effect of flow reversal is similar. Author