Turbine blade cooling technology development

Internal air cooling above the melting point of the alloy; zirconium oxide TBCs as the only ceramic matching the CTE of nickel; $5,000-per-blade cost driven by EB vapor deposition.

Then they went to cooling. [Tom holds up a turbine blade with internal cooling passages.] It's got internal cooling passages. If you take some of the other courses, I'll talk more about how they make that. They went to internal cooling, and the interesting thing here is you see this jump in temperature — about 1,300 degrees centigrade. That's above the melting point of the material. If you didn't have that cooling, your engine would melt. The cooling is actually thousand-degree Fahrenheit air that comes from the compressor. As long as the turbine is running, you always have cooling air — unless something gets plugged up.

Tom's $2B (1990s, now ~$6B) fuel savings for a 50°F operating temperature increase. Gas at 3,000°F running over a 2,400°F-melting-point alloy, kept solid by compressor-bled cooling air. Includes the historical attribution to Professor Schenck at MIT and Nick Grant, who developed the underlying alloy technology at Pratt Whitney in the 1960s–70s.

You have to understand this is an old figure from the 1990s, and you can probably double it or triple it, but a 50 degree Fahrenheit increase in operating — and you know the efficiency of even genuine thermodynamics, you worry about delta T over T — back in the 90s that was two billion dollars in fuel savings for the airlines. Fuel was a lot cheaper then; it's probably six billion dollars to get a 50 degree temperature increase. What have they done to do that today?