A theoretical and experimental study on flow characterisation in an acoustically excited chamber

Flame–acoustic wave interactions have been studied widely in the combustion community; however the whole physicochemical mechanism is still not clear. The present research aims to analyse the acoustic model inside an enclosed combustion chamber and to gain more detailed data to further study flame/acoustic interactions theoretically. The acoustic coupling can be calculated by using linear acoustic equations. The theoretical acoustic model has been developed to analyse the acoustic response for the present square tube and acoustical system. A good agreement between experimental measurements and theoretical predictions were proved by measuring the pressure and velocity fields of acoustic wave. The first four measured harmonic frequencies match well with theoretical prediction. The measured acoustic pressure node and anti-node region were also the same as theoretical prediction. However, due to the neglect of pressure drop loss in the upper end of the tube, the theoretical prediction data was from 23% to 43.3%, higher than that of the experimental measurements.