Near-field Film Thickness Measurements of an LPRE Swirl Injector Spray

摘要

A novel approach to the measure of liquid film thickness in the near-field of a liquid rocket swirl injector spray was developed. Archived data were analyzed, wherein liquid mass flow was throttled over a range of 0.064 to 0.082 kg/s-corresponding to injection pressure drops of 0.80 to 1.26 MPa. For these conditions, digital images of the swirling liquid sheet were deconvoluted with an Abel transform technique and processed with an objective film thickness measurement algorithm. Measurements were benchmarked against theoretical values of the injection film thickness, as well as empirical predictions of film thickness at the injection plane and slightly upstream within the injector nozzle. Results suggest this approach successfully discerns film thickness; however, uncertainties associated with the measurements limit definitive physical insight on film thickness behavior as a function of the particular test conditions presented in this work.