Transient response of a liquid injector to a steep-fronted transverse pressure wave

D Lim,S Heister,B Kan,D Stechmann

doi:10.1007/s00193-017-0787-8

Abstract

Motivated by the dynamic injection environment posed by unsteady pressure gain combustion processes, an experimental apparatus was developed to visualize the dynamic response of a transparent liquid injector subjected to a single steep-fronted transverse pressure wave. Experiments were conducted at atmospheric pressure with a variety of acrylic injector passage designs using water as the working fluid. High-speed visual observations were made of the injector exit near field, and the extent of backflow and the time to refill the orifice passage were characterized over a range of injection pressures. A companion transient one-dimensional model was developed for interpretation of the results and to elucidate the trends with regard to the strength of the transverse pressure wave. Results from the model were compared with the experimental observations.

Highlights

Pressure gain combustion (PGC) research has been rapidly gaining attention as a potential means to produce thrust or generate power at higher efficiency than conventional constant-pressure combustion technology [1,2]
The annular rotating detonation engine (RDE) combustion chamber contains one or more azimuthally traveling detonation waves traversing the annulus at velocities approaching the Chapman–Jouguet (CJ) value, while regions downstream of the wave passage supply fresh propellants to support the perpetuation of the incoming wave
Because detonation waves can travel at speeds well over 1000 m/s, injectors in these devices are subject to dynamic downstream pressures oscillating at kilohertz frequencies

Summary

Introduction

Pressure gain combustion (PGC) research has been rapidly gaining attention as a potential means to produce thrust or generate power at higher efficiency than conventional constant-pressure combustion technology [1,2]. These transient devices rely on the detonative mode of combustion as opposed to deflagration at constant pressure, as is com-. The transient injection flow recovery subsequent to wave passage must be understood in order to assess injection and filling characteristics that prepare the combustible mixture for the arrival of a detonation wave [3]

Methods

Results

Conclusion