The dual-bellnozzle has an inflection point (12) between the first stage nozzle and the second stage nozzle.
双钟形喷嘴具有位于第一级喷嘴和第二级喷嘴之间的拐点 （12）。
2
When numbers of the inner nozzle are enough, plug nozzle has less size, less weight and higher thrust efficiency than the bellnozzle under same area ratio.
在单元数足够多时，环簇式塞式喷管可比相同面积比的钟形喷管的尺寸更小，重量更轻，推力效率更高；
3
By employing the gaseous oxygen as oxidizer and gaseous hydrogen as fuel, hot-firing tests were performed for aerospike nozzle and dual-bellnozzle test engines with altitude compensating features.