Independent Stage Control of a Cascade Injector

Abstract

A comprehensive investigation of independent stage control as applied to a cascade injector was completed. It was experimentally demonstrated that altering the number of active stages in the cascade could control the plume structure of this injector. Influence coefficient analysis showed that the first stage governed penetration height. Power law correlation comparison found the cascade injector penetrated higher than a normal, circular injector by a factor of 3.5.Corresponding computational data showed agreement with the experimental data in terms of penetration distance, but less accuracy in predicting plume width. A turbulence model study indicated the Menter model to have the closest agreement with experimental data. However, the fine grid solution produced using Wilcox k-ω was later found to have better agreement. The computational data was also used to produce a synthetic signal similar to the experimental planar laser induced fluorescence signal that improved agreement with the experimental data. Additional support was a grant of computer time on the SGI Origin 3900 provided by the Aeronautical Systems Center Major Shared Resource Center Department of Defense High Performance Computing Modernization Program at Wright-Patterson Air Force Base. Support from the staff of this center as well as the Research Air Facility personnel are recognized and appreciated. Mr. D. Schommer and Mr. W. Terry are gratefully acknowledged for their contributions to experimental set-up, testing, and overall laboratory support during this project. The assistance provided by Mr. C. Smith and Mr. K. Kirkendall to bench test and seal the injector is appreciated. Mr. G. Streby is thanked for his design and engineering support. Computer support provided by Mr. M. List and First Lieutenant J.

Supersonic Combustion Using a Stinger-Shaped Fuel Injector

“…The non-intrusive methods are classified into three categories: angled injection [10][11][12], port geometry optimization (elliptical [11,13], wedge [14], or diamond [15][16][17] shapes), multi-array injection (e.g., aeroramp [18,19], staged [20], and cascade [21,22] injectors), and their combinations. Low-angled injection systems [10,11] and the aeroramp injector [19] exhibited jet penetration trends similar to those of the physical ramp injector.…”

“…Tandem two-staged injection behind a backward-facing step exhibited that the blockage effect of the upstream jet facilitated the penetration of the downstream jet [20]. A cascade injector [21,22] is a more progressive design actively using the tandem effect to increase the jet penetration.…”