Assessment of the Fluidic Control Boundary Nozzle within a Pulse Detonation Rocked Engine by Unstructured Meshes CE/SE Method

Abstract

The simulation model of pneumatic Fluidic Control Boundary Nozzle(Fluidic nozzle) is built to study its operation and propulsive augmentation performance in the unsteady PDRE system. The numerical simulation employed an adaptable unstructured-mesh CE/SE method, which is found capable to solve flows with strong gradients in detonation tube and complicated wave interaction patterns in fluidic nozzle. It is found that during the detonation and earlier exhaust stage, the whole section of fluidic nozzle is used to expand and increase the thrust without any over-expansion appearing in the nozzle. Conversely, during the later exhaust stage, purge and refilling stage, the annular control surface by subsonic jet of fluidic nozzle is successfully formed on the outside of main stream to avoid harmful shock waves of over-expansion. Thus, the real expansion ratio and thrust efficient are optimized. It is also found that easier for the bell fluidic nozzle to control the outer interface of main supersonic flow, while it is easier for the conical fluidic nozzle to perfect the real expansion ratio of main flow. The research results enrich the research system of PDRE nozzle.