The Civic: A Concept in Vortex Induced Combustion for the Solar Gemini 10 kW Gas Turbine

Abstract

The Radial Engine Division of Solar Turbines International, an Operating Group of International Harvester, under contract to the U.S. Army Mobility Equipment Research & Development Command, developed and qualified a 10 kW gas turbine generator set. The very small size of the gas turbine created problems and, in the combustor, novel solutions were necessary. Differing types of fuel injectors, combustion chambers, and flame stabilizing methods were investigated. The arrangement chosen had a rotating cup fuel injector, in a can combustor, with conventional swirl flame stabilization but was devoid of the usual jet stirred recirculation. The use of centrifugal force to control combustion conferred substantial benefit (Rayleigh Instability Criteria). Three types of combustion processes were identified: stratified and unstratified charge (diffusion flames) and pre-mix. Emphasis is placed on five nondimensional groups (Richardson, Bagnold, Damko¨hler, Mach, and Reynolds numbers) for the better control of these combustion processes.

Ongoing Development of a Low Emission Axisymmetric Annular Vortex Combustor for an Industrial Gas Turbine

“…1 and are described in Ref. (4). All the air required for combustion is passed through an air swirler.…”

“…In either case, the same effective flow area is used. The length and total flame zone volume of the assembly of small can combustors would be reduced by a factor of as compared to the length and volume of the single large can combustor (4).…”

“…This paper describes similar techniques applied to the Mars 7500 kW engine (2). It complements work (3,4) using similar vortex combustors, to investigate emission control in high altitude aero gas turbines and to resolve field service problems of the Gemini 10 kW gas turbine. Tests were carried out at atmospheric pressure using natural gas.…”