vivek beri 319 days ago

The Trent XWB engine; the turbine blades sit just in front of the flared region at the back

This means the blades operate in an environment several hundreds of degrees hotter than the melting point of the nickel alloy. To stop them melting, the metal must be cooled. This is done via two mechanisms: the blades are coated with a low-conductivity ceramic; and they are riddled with a complex, branching structure of internal channels. “Air is drawn from the HP compressor, routed through the core of the engine and into the root of the blades,” explained Glover.

“It passes through the cooling channels and exits through a myriad of holes in the surface of the blade, to create an envelope of cool air around the blade. So the metal is never above its melting point, even though the environment is. The cooling air isn’t actually that cool; it’s at about 600–650°C, but we have to take it from the hot core of the engine so it has enough pressure to get through the channels and out of the holes. It’s still enough to keep the blade temperature down to about 1,150°C.”

Heat is vital to jets; the hotter they can operate, the more energy they can extract from their fuel. This is the major point of competition between engine makers, so over the six decades jets have been in operation, forcing the temperature higher, and developing turbine blades that can withstand the heat, has been one of the most important technology races in the sector. It’s been a gradual process, Glover said, culminating in