| The present investigation is motivated by vibration and instability problems in solid propellant rocket motors. A class of interior flows modelled to simulate flow conditions inside rocket motor cavities is considered. The turbulence generated pressure fluctuations are shown to consist of two components--acoustic and hydrodynamic. A theory of aeroacoustics is employed to extract acoustic pressure spectra from experimentally obtained turbulence data and acoustic impedance values at flow boundaries. The effects of turbulence intensities, sidewall acoustic impedance, axial mass blowing distribution, length to diameter ratio of the cavity and different mass flux on the acoustic pressure level are investigated in experimental configurations. Typical pressure levels inside rocket motor environments are calculated utilizing a particular representation for propellant response. Estimates of the hydrodynamic component of the pressure fluctuations are provided for the case of fully developed turbulent pipe flow. |
