Close-Coupled Fuel Injector/Flameholder Concept Featuring Direct Fuel Injection Into Flameholder Wake

Close-coupled fuel injector/flameholders used in modern augmentors face difficult challenges in static stability due to higher airflow velocities and higher levels of vitiation than past augmentors. In addition, close-coupled fuel injection schemes typically employ jet-in-crossflow methods to adequately penetrate and mix the fuel with the airstream, but have difficulty providing sufficient fuel to the flameholder wake to anchor the flame. In this SBIR program, CFDRC proposes to investigate novel fuel injection concepts that inject a small percentage (~10%) of the fuel directly into the flameholder wake to control the wake fuel-air ratio, without disrupting the wake recirculation zone. In Phase I, a combined numerical/experimental program is proposed that will study preliminary designs. Various methods of injecting the wake fuelflow will be studied numerically, using advanced 3D RANS and LES methods, and the best concept(s) selected for single flameholder testing. To show feasibility, blowout testing at realistic augmentor conditions will be performed at existing Energy Research Consultants (ERC) facilities. In Phase I Option, additional analysis/testing will be performed to study alternative fuel injection schemes. In Phase II, optimized designs that include flameholder cooling flow will be developed and tested, followed by sector testing of the concept at General Electric in Phase IIe. If successfully demonstrated to GE satisfaction, GE will consider full engine testing of the concept in Phase III.