| Contra-rotating turbine technology has advantages in pre-cooled engines both for advanced launchers and for hypersonic civil transport when an air compressor is driven by a helium or hydrogen turbine (giving a large speed of sound mismatch between the turbine and compressor). Selecting a contra-rotating turbine increases relative bladespeeds and eliminates the turbine stators giving a mass saving and efficiency increase.
As part of the LAPCAT study a contra-rotating turbine has been designed by the Von Karman Institute and optimised by genetic algorithm methods by Cenaero.
To verify the turbine performance a model turbine has been constructed by Quadratec Ltd and is currently being tested at Reaction Engines B9 test site. This model turbine is full linear scale but uses argon as the working fluid rather than helium to reduce cost and power. The rig operates with reduced inlet temperature and pressure enabling cheap reinforced plastic blading.
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