Tests keep turbines running above blade melting point

Their current focus is to improve the turbine blades spun by the engine’s exhaust.

‘Right now, the current state-of-the-art for engine combustion is about 3,000 degrees Fahrenheit,’ said Hu, an Iowa State professor of aerospace engineering. ‘That temperature is above the melting temperature of all engine materials. If you don’t have cooling technologies, all the material will melt.’

One technology is to build hollow turbine blades and blow coolant through an arrangement of holes in the blades. The holes create a cooling film between the hot exhaust gases and the turbine blades, allowing the blades to keep their shape and strength.

However, temperatures are rising as manufacturers experiment with biofuels and efficiency improvements, expediting the need for heat-resistant materials and cooling technologies that can lead to fuel savings, longer-lasting parts and significant cuts in operating costs.

For the past 19 months, Hu and Johnson, an Iowa State post-doctoral research associate in aerospace engineering, have been working with the GE Global Research Center in Niskayuna, New York to study turbine blade cooling.