| ||STATEMENT OF INTENT: Develop advanced combustor design
|| Objective: ||Develop advanced combustor designs preserving existing inlet swirl, thereby increasing overall engine efficiency.
|| Description: ||Legacy combustor designs generally include a diffuser which removes the inherent swirl out of the flow before it reaches the combustor inlet. However, novel ideas such as high g combustion utilize high circumferential flows to decrease combustor size allowing for inter-turbine burning (ITB) and providing increased efficiency. Initial designs for these high g combustor/ITB concepts have included bleed air being forced into the circumference of the combustor cavity at an angle to attain the high g flows. This work seeks to utilize the inherent swirl found exiting the compressor and/or turbine to generate the high g flow necessary in the circumferential cavity to attain high g combustion. Successful designs would result in improved overall efficiency, decreased combustor radius, and decreased weight.
|| ||PHASE I: Numerically analyze several different swirl-conserving combustor/ITB inlet designs. Identify critical design parameters that impact combustion in naturally induced swirl environments. Demonstrate feasibility of at least two numerically optimized designs.
|| || ||PHASE II: Experimentally test each optimized design, compare experimental and numerical results. Continue to refine the swirl conservation design with experimental results. Demonstrate design ability to conserve swirl, producing high circumferential flows in a circumferential cavity where combustion is occurring.
|| ||DUAL USE COMMERCIALIZATION: Military application: The weight and size reductions possible through the proposed research would significantly benefit military applications from small unmanned aerial vehicles (UAVs) all the way to larger aircraft. Commercial application: The design proposed can benefit commercial and military gas turbine users, as well as ground-based and auxiliary power units.
|| References: ||1. General information on the Propulsion Directorate can be found at: http://www.pr.afrl.af.mil .
2. Anthenien, R.A., Mantz, R.A., Roquemore, W.M., and Sturgess, G., "Experimental Results for a Novel, High Swirl, Ultra Compact Combustor for Gas Turbine Engines," Proceedings from Western States Section Combustion Institute Meeting, Berkeley, CA, March 27, 2001.
3. Lewis, G.D., "Centrifugal-Force Effects on Combustion," 14th Symposium (International) on Combustion, The Combustion Institute, pp. 413-419, 1973.
|Keywords: ||combustors, ignition, blowout, turbulence, stability, swirl, high g combustion, |