The invention discloses an adjustable spray
pipe suitable for a high-frequency time-varying flow field of a rotary
detonation combined engine, and relates to the field of combined power engines. The spray
pipe is composed of a spray
pipe inner cone, a spray pipe outer cover, a spray pipe inner cylinder composed of a movable piece and a fixed piece, and an electric push rod. The structure is characterized in that an outer
culvert flow channel is designed according to an outlet flow field of the rotary
detonation engine and is matched with an annular rotary
detonation engine
combustion chamber, and high thrust is ensured. The spray pipe inner
barrel movable piece serves as a movable plug cone of the plug type spray pipe and slides on the spray pipe inner
barrel fixed piece through traction of the electric push rod, and the
throat area of the outer
culvert and the
throat area of the inner
culvert are adjusted. According to the design, the engine is allowed to use the inner culvert flow channel to exhaust in a low-altitude low-Mach-number
turbine mode and use the outer culvert flow channel to exhaust in a high-altitude high-Mach-number rotating detonation
stamping mode. By adjusting the elongation of the electric push rod, the pressure change of the
working environment of the engine is matched, the work of the spray pipe is optimized, and the heat-work conversion efficiency of the rotary detonation
stamping combined engine in a wide speed domain range is improved.