– How do jet engine turbine blades not melt?


Jet engines work at a higher temperature that the melting point of Titanium Superalloy so how do they not melt?

In: 219


They pump cool air through them, which exits out of holes on the leading edge, and sometimes the surface, of the blade. This creates a thin layer of cool air on the outside surface.

Temperature is really irrelevant here as long as you can cool off the engine with auxiliary processes. For one, these engines are coated with thermal barrier coatings. There’s also a technique, which I believe answers your question directly, “film cooling” that simply channels the cooler air to the engine surface and reduce the incoming hot air’s effect. This means that the temperate lowers down before it even touches to the surface.

Cooling channels in the blades. They bleed cooler air through and out of little holes in the things which in addition to cooling the blade, also adds a thin buffer layer of cool(er) air over the blade. Additionally the blades generally get coated with a thin high temp layer that isn’t as mechanically strong, but has better high temp properties. Could be Nickel Aluminum which seems to be the go-to for jets, or a ceramic coating which seems more used in like power station gas turbines.

Heat doesn’t transfer instantly. If you can cool off a material faster than the exhaust gases can transfer heat into it you end up in a balance where the material ends up at some temperature in between.

They do experience some degradation over time, from elevated temps, but they won’t get hot enough to melt or fail for their rated lifetime.

they blow cold air through them, watch AgentJayZ on youtube to to learn more than you ever wanted to know about turbine engines