Water turbine like a true turbine. Fausto Veranzio in his book "Machinae Novae" (1595) described a vertical axis mill with a rotor similar to that of a Francis turbine. Johann Segner developed a reactive water turbine (Segner wheel) in the mid-18th century in Kingdom of Hungary. It had a horizontal axis and was a precursor to modern water turbines. It is a very simple machine that is still produced today for use in small hydro sites. Segner worked with Euler on some of the early mathematical theories of turbine design. In the 18th century, a Dr. Robert Barker invented a similar reaction
Gas turbine gas turbines/auxiliary power units A major challenge facing turbine design is reducing the creep that is induced by the high temperatures. Because of the stresses of operation, turbine materials become damaged through these mechanisms. As temperatures are increased in an effort to improve turbine efficiency, creep becomes more significant. To limit creep, thermal coatings and superalloys with solid-solution strengthening and grain boundary strengthening are used in blade designs. Protective coatings are used to reduce the thermal damage and to limit oxidation. These coatings are often stabilized zirconium dioxide-based ceramics. Using a thermal protective coating limits the temperature exposure of the