关键词: 压力振荡;声学振型;定容弹;阻尼特性;半带宽

Abstract: In order to determine characteristic frequencies of acoustic modes of the chamber and their damping characteristics， the corresponding numerical simulation methods based on numerical constant-volume bomb and half-power bandwidth method were developed. Thereby， the most inspirable acoustic mode and the acoustic mode that is the most difficult to be attenuated can be both achieved. Then damping characteristic of a small-thrust attitude and orbit control thruster was predicted by imposing numerical constant-volume bomb at the region near the side-wall. Multi-acoustic modes are stimulated， in which the first tangential mode is the most inspirable acoustic mode， while the first longitudinal mode is the one that is the most difficult to be attenuated. Furthermore， effects of configuration parameters of chamber on its damping characteristic were discussed. With the increase of the diameter of chamber， longitudinal modes are suppressed， while tangential modes are more difficult to be attenuated. With the increase of contraction ratio of chamber， half-power bandwidth of the first tangential mode increases first and then keeps almost the same. With the increase of the length of the cylindrical part， there isn’t obvious trend of half-power bandwidth of each excited mode.

Key words: Pressure oscillations;Acoustic mode;Constant-volume bomb;Damping characteristics;Half-power bandwidth