Design of a supersonic double combustion chamber for solid fuel

The design of an air-fed supersonic combustor of dual type using a solid fuel, is proposed. The fuel is burned in a secondary combustor chamber under oxidizer-starved conditions where a small fraction of the main feed air stream is decelerated to subsonic conditions. The combustion products, consisting of a mixture of combustible gases and active radicals, are then accelerated back to sonic conditions and injected into the primary chamber where they are mixed with the main air stream and burned under supersonic conditions. The fuel is polyester containing a small amount of ammonium perchlorate. The secondary chamber was designed as a subsonic solid fuel ramjet and the primary chamber followed the classic model. The main conclusion is that it is necessary to investigate further solid fuels which display high regression rates under low pressure while maintaining acceptable mechanical properties.