Compressor  AVC Expander Gas Turbine Engine


Ramgen Planar Nozzle Expanders

Just as supersonic flight inlets are commonly used to efficiently decelerate and compress an air stream for use by a jet engine, supersonic nozzles are routinely used in ramjet and rocket systems to achieve the expansion and acceleration of gas streams in a wide variety of propulsion systems.

Figure 1 shows a picture of the Space Shuttle Main Engine “SSME” during a full power test. When operating at its design point, the bell shaped nozzle of this rocket engine efficiently expands the high pressure and high temperature gases in the SSME combustion chamber from 3000 psia to 9 psia, generating a high velocity exhaust stream that is the source of the thrust for the vehicle.

Space Shuttle Main Engine

Just as the shock compression features of the supersonic flight inlet were incorporated into the rim of the supersonic compression stage, the planar expansion surface of the supersonic nozzle can also be incorporated into the rim of a supersonic expansion stage.

Ramgen has used its proprietary know-how, validated with CFD simulations to develop supersonic compression stages that are well matched in mass flow and pressure ratio/expansion ratio capability to these expansion stages. This is an important requirement in an integrated engine system, and both processes must accomplish efficiently in order to generate useable power.


The background information that Ramgen developed during it original 10MW engine efforts will serve as the basis for applying the technology in the proposed ASCE engine, currently in a preliminary evaluation phase with DARPA.

Ramgen is also in the early stages of identifying high value applications for its expander technology, but already it seems apparent that there is going to be interest in a high efficiency, high expansion ratio capability for the same reasons that the compressor technology is of interest.

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