vadodara wrote:Sokes wrote:[
Concerning pollution with the B787:
"Cracking problems in the intermediate pressure (IPT) section of the turbine have plagued the engine since early 2016, five years after its launch.
According to Horwood, the problem was caused by sulphurisation; a chemical process affecting the nickel alloy which comprises the IPT blades. “We are very confident that this problem will not occur in any of our other engines,” Horwood said. “This is confined to component level in the Trent 1000.”
Precisely! The engines were not tested in harsher environments.
IndiGo planes also fly to arid and dusty climes of the Arabian peninsula. The engine maker needs to be cognizant of the operating conditions.
Dust is not nice but regular a little less a problem. Next to erosion of parts, it will be an issue in the high and low pressure extreme hot turbine parts.
The sulfur dioxide is another story, SO2 itself does not do much, but from SO2 you get SO3 (regular in form of H2SO3 and this is corrosive).
If I am not wrong, is SO3 not produced in the chemical industry from SO2 under high pressure and temperatures around 400 to 600°C? Of course, additional catalyst is part of it, but catalyst only accelerate the reaction.
Are these not the conditions in the high pressure compressor stage of a turbofan engine? SO3 2- is extreme high corrosive.
And as said, nowhere in the world is the air so badly polluted as in northern half of India, especially with SO2.