Aerojet-general Corporation

Other

Power Play Energy L.l.c.

Ross A Hewitt

Jackson I Ito

Felix F Chen

John L Grimes

Randall L Peeters

Joseph P Maceda

Kenneth P Klaas

Svein Hestevik

A combustion chamber/supersonic nozzle assembly is cooled by an array of coolant channels in the wall of the assembly with coolant being fed to the assembly at the throat plane between the subsonic (convergent) and supersonic (divergent) sections. A minor portion of the coolant entering at the throat plane is directed to coolant channels in the supersonic section wall, while the remainder is directed to a complex arrangement of channels in the subsonic section wall. The latter arrangement includes an outer layer of wide axially oriented channels for delivery of coolant to, and removal from, an inner layer of smaller, circumferentially oriented channels that are adjacent to the hot gas and carry the bulk of the coolant load. The path of coolant travel through each inner channel is relatively short, lessening the pressure drop through those channels relative to coolant channel arrangements of the prior art.

Rocket engine chamber with layered internal wall channels

The present invention provides heat exchanging elements for use in Stirling engines. According to the present invention, the heat exchanging elements are made from muliple platelets that are stacked and joined together. The use of platelets to make heat exchanging elements permits Stirling engines to run more effiecient because the heat transfer and combustion processes are improved. In one embodiment, multi-stage combustion can be introduced with platlets, along with the flexibility to use different types of fuels. In another embodiment, a single component constructed from platelets can provide the heat transfer rquirements betweeen the combustion gas/working gas, working gas in the regenerator and the working gas/coolant fluid of a Stirling engine. In another embodiment, the platelet heat exchanging element can recieve solar energy to heat the Stirling engine's working gas. Also, this invention provides a heat exchanging method that allows for multiple fluids to flow in opposing or same direction.

Stirling engine having platelet heat exchanging elements

In a supersonic nozzle incorporating injectors and a combustion chamber as part of an expander cycle rocket engine, the oxidizer is injected in two streams. One of the streams, preferably a small fraction of the total, is injected into an upstream or preburner section of the combustion chamber and the other to a downstream or main section of the chamber. The preburner combustion gas is cooled in a substantially uniform manner to a moderate temperature by cooling the bulk of the gas rather than cooling only the gas in a boundary layer adjacent to the chamber wall. The combustion gas produced in the downstream section is hotter, and heat from that gas is drawn through the chamber wall into a jacket. The limited combustion in the preburner permits the use of a cooling element with highly intimate heat exchange construction, extracting a high level of energy from the preburner gas without damage to the cooling element and an overall improvement in the regenerative cooling.

Expander cycle rocket engine with staged combustion and heat exchange

A convergent-divergent rocket nozzle is formed by joining two coaxially aligned conical sections at a throat plane, each diverging outward from the throat plane. Coolant channels formed in the wall of the nozzle are arranged in spirals around the nozzle axis. Preferably, the conical sections are formed from platelet laminates rolled into conical form with a single spiral seam, and at least one of the conical sections is a composite of two or more component conical sections separately formed and then joined in a nested arrangement with the seams not superimposed. A further preferred construction is one in which the convergent end of one conical section is split radially into strips that are then spread apart to serve as bonding surfaces to bond to the other conical section.

Nozzle with spiral internal cooling channels

Heat is extracted from the combustion gas in a rocket engine combustion chamber by diverting portions of the gas through channels in the nozzle wall. The channels are layered between channels of coolant, which in expander cycle rocket engines is uncombusted fuel, to achieve intimate heat exchange between the combustion gas and the fuel. The combustion gas channels are relatively short, returning combustion gas thus cooled to the chamber interior. By drawing combustion gas from the chamber interior into the chamber wall, the cooling process no longer relies on the combustion gas boundary layer for heat transfer as in the prior art.

Diversion of combustion gas within a rocket engine to preheat fuel

The present invention provides heat exchanging elements for use in Stirling engines. According to the present invention, the heat exchanging elements are made from muliple platelets that are stacked and joined together. The use of platelets to make heat exchanging elements permits Stirling engines to run more effiecient because the heat transfer and combustion processes are improved. In one embodiment, multi-stage combustion can be introduced with platlets, along with the flexibility to use different types of fuels. In another embodiment, a single component constructed from platelets can provide the heat transfer requirements between the combustion gas/working gas, working gas in the regenerator and the working gas/coolant fluid of a Stirling engine. In another embodiment, the platelet heat exchanging element can recieve solar energy to heat the Stirling engine's working gas. Also, this invention provides a heat exchanging method that allows for multiple fluids to flow in opposing or same direction.

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Sacramento, CA, United States of America

Ross A Hewitt