High-Temperature Combustor and Seal for a Water Piston Propulsor

摘要

The detailed design and testing of a high temperature combustor and seal for aWater Piston Propulsor is reported. The system is comprised of a high pressure combustor together with a carbon graphite rotor-contacting face seal. Analyses are presented to support the design of an air cooled combustor liner. The seal is pneumatically loaded against the rotor face using a variable pressure. Superalloy materials are selected for most components with a vitreous enamel corrosion resistant coating applied to the high-temperature combustor liner. The combustor was subjected to a series of rig tests to define its performance prior to integrating it with the rotor system. A simulated rotor test was also conducted to study the seal plate bellows pressure relationship required to attain a satisfactory seal. After the Solar combustion and seal system was integrated with the rotor system, three series of water channel tests were conducted to determine the overall system performance. The combustor performed satisfactorily although the imposed operating conditions, i.e. pressure and air flow, were significantly different from the original design specifications, requiring the combustor to operate at higher combustor loadings. The tested propulsion efficiency of the WPP was lower than predicted. An attempt to improve performance by matching the shape of the combustor outlet to the roto passage inlet yielded minimal improvements.