An overview on experimental study of vortex-acoustic coupling in segmented solid rocket motors

Experimental researches on pressure oscillations in large segmented solid rocket motors due to vortex-acoustic coupling phenomenon were overviewed, including cold flow setups with air injected axially and radially, as well as lots of subscale motors hot fires. One side, the values of Strouhal number used to define the vortex shedding frequency were determined and verified, which can explain the time when instabilities occur and the paths of frequencies in a full-size motor. On the other side, effects of the height, thickness, material, locations of inhibitors on amplitudes of oscillations were investigated, which provides some ideas for passive control. Besides, head cavity, intersegment cavity and cavity at submerged nozzle also have a great impact on amplitudes of oscillations.