Ceramic matrix composites for turbine engines

Question 1

How does a turbine engine work?

Answer 1

~ atmospheric air is drawn into the compressor, pressurizing it

~ fuel is sprayed in and ignited. Combustion substantially raises the temp and pressure

~ this drives a turbine, which in turn operates the upstream compressor

Question 2

How is power generated?

Answer 2

~ the turbine is used to generate electricity

~ for jet engines, the remaining energy of the exhaust that isn’t used for shaft work produces thrust

~ gas turbine engine waste heat is recovered to power a conventional steam turbine (65% efficiency)

Question 3

What increases fuel efficiency?

Answer 3

~ turbine engine temp

~ Ni-Co superalloy-based turbine engines can run hotter because parts are treated with thermal barrier coatings (stabilized zirconia)

~ ceramic matrix composites can withstand ~200 higher temperatures, 1300C
–> CMC’s are 1/3 the weight of metal and don’t need to be air cooled (inner air cooling channels in metal blades), lighter and more efficient engines