ANALYSIS OF ACOUSTIC WAVES IN A COLD-FLOW ROCKET

A promising method for determining the losses in a rocket chamber during combustion-instability is based on acoustic measurements at room temperature. This method permits the losses to be determined from experiments in a small-scale model fo the actual chamber. The calculations presented here treat the acoustics of a chamber with mean flow; they are intended to be used in the design of such experiments and in the interpretation of data. Results have been found for application to the three kinds of measurements-transient decay of waves, the frequency response (resonance curve), andhe standing wave ratio. Of these, perhaps the simplest is measurement of the resonance curve; the principal contribution here is a graphical means of interpreting such data.