Design and Test of a Low-Cost Combustor for Expendable Turbine Engines

Abstract

Application of the gas turbine for use in unmanned military aircraft and missiles, industrial or vehicular power applications, and inexpensive general aviation aircraft is possible only through development of low-cost engine components. This paper presents the design and development of an annular fuel vaporizing combustor for a low-cost turbojet for use in a supersonic missile and other expendable or limited-life applications. The design of the low-cost gas turbine and the factors that influence the selection of component characteristics, design configurations, materials, and methods of manufacture are discussed. In order to provide high specific power, the highest burner temperature possible, without introducing design complexity and performance and cost penalties associated with turbine cooling, was selected. Consequently, the combustor's influence on turbine performance and durability had a significant effect on the engine design and cost. The combustor performance goals, including efficiency and temperature pattern factor as provided within envelope, reliability, and cost constraints, are described. An experimental combustor test program was conducted to evaluate the design pertaining to liner cooling, pyrotechnic ignition, fuel introduction, primary and dilution air distribution, and exit gas temperature profiles. The combustor test results and the influence of combustor performance on turbine life are discussed.