Experimental and Numerical Investigations of a Bypass Dual Throat Nozzle

Abstract

The bypass dual throat nozzle (BDTN) is a new kind of fluidic vectoring nozzle. A bypass is set between the upstream convergent section and upstream minimum area based on the conventional dual throat nozzle (DTN). The BDTN shows a minimum or even no penalty on the nozzle's thrust performance, while it would be able to produce steady and efficient vectoring deflection similar to the conventional DTN. A BDTN model has been designed and subjected to experimental and computational study. The main results show that: (1) BDTN does not consume any secondary injection from the other part of the engine, while it can produce steady and efficient vectoring deflection. (2) Under the same condition, it can provide the maximum thrust vectoring efficiency of all the known fluidic thrust vectoring concepts reported in the literature. (3) The thrust vector angle is also greater than that of the conventional DTN that has been reported up to now. Especially, under NPR = 10, the thrust vector angle of BDTN can reach 21.3 deg. (4) For a wide NPR range from 2 to 10, the BDTN generates the best thrust vectoring performance under NPR = 4. Above all, the BDTN is well suited to produce vectored thrust for nozzles.