Noise control for enclosed spaces continues to be a very important topic. Traditional passive techniques are often not feasible because of the inherent excessive weight penalty associated with the method. This is particularly true for aircraft or spacecraft environments. Recently, active control methods have received more attention and early results are promising. This project extends this active control thrust. It investigates the fundamental problem of controlling the noise within a cylindrical shell by applying control forces to the shell wall in order to reduce particular vibration modes associated with transmitting acoustical energy into the enclosed cavity.
