Motive sealing structure of variable-geometry combustor of rocket based combined cycle engine

Abstract

The invention discloses a motive sealing structure of a variable-geometry combustor of a rocket based combined cycle engine. The mode that contact type sealing and non-contact type sealing are combined is adopted, so that rotary motive sealing of the joint of hinges and transverse motive sealing of all top plates and side plates of the combustor are achieved. A sealing groove is formed in the end face of a connection flange between the fixed section and the variable section of the combustor. Sealing grooves are formed in the two side edges of a bottom plate of an inner cavity of the combustor. The top plates of the inner cavity of the variable section of the combustor are connected with arc grooves to form mechanical sealing. Graphite bars in longitudinal grooves and a rotation shaft are sealed through packing. The top plates of the variable section of the combustor are provided with labyrinth channels. The top plates and the side plates are in transverse motive sealing. Red copper bars in the horizontal grooves formed in the side faces of the top plates and the side plates are sealed through packing. The red copper bars of every two top plates are attached to the joints of the top plates to achieve mechanical sealing. The sealing structure can meet the sealing requirement of the engine and also has the advantages of being simple in structure, convenient to machine, and easy to implement.

Description

technical field [0001] The invention relates to the technical field of rocket ramjet engines, in particular to a dynamic sealing structure of a variable geometry combustion chamber of a rocket-based combined cycle engine. Background technique [0002] As the most promising and potential power device for future aerospace vehicles, the Rocket-Based-Combined-Cycle (RBCC) engine is an organic combination of a ramjet engine and a rocket engine in the same flow channel, taking into account the advantages of both . It not only improves the performance of the engine, but also can realize from zero-speed take-off to hypersonic flight, and even complete orbit directly, which greatly broadens the speed-altitude flight envelope of the aircraft. The working process of rocket-based combined cycle engine includes ejection mode, sub-ramming mode, scramming mode and pure rocket mode. The sub-combustion ramming mode needs to accelerate the subsonic gas to supersonic speed through the flow c...

AI Technical Summary

Problems solved by technology

In order to solve this technical problem, NASP proposed a high-temperature ceramic sheet dynamic seal and a braided fiber rope structure seal in the document "Evaluation of an Innovative High Temperature Ceramic Wafer Seal for Hypersonic Engine Applications", but these two sealing methods are complex in structure, difficult to design and process, and high in cost.

For ground test engines with short working hours, the above two solutions will lead to high research costs and are not easy to implement

Images