Abstract:
A study is made of some existing analytical, numerical and experimental results for gas jets expanding out of axi-symmetrical nozzles. Jets expanding into a vacuum and into still air at finite pressure are considered in detail, and by introducing certain new ideas the existing results are expressed in a compact form and thereby rendered more widely applicable. A brief examination of jets expanding into supersonic airstreams suggests that some information about the flow fields of rocket jets at high altitudes may be deduced from the extended results for still-air jets in which the reference pressure at the nozzle exit is much greater than the ambient pressure; an example for a particular rocket and a specific trajectory is given.
