The beauty of electronics work

[Boncuk]

I am familiar with the cooling holes in military jet turbine blades. Not titanium though, but some super hard stainless steel super alloy.

The method I described is used at MTU (Motor & Turbine Union, Munich). They made the engines for the C160 (Transall, a twin turbo prop engine transport plane capably of 16 metric tons of cargo).

We landed at Griffith AB (NY) one day and somebody said: "What a cute little plane! How did you get it over the ocean?"

Boncuk

 

[Warpspeed]

The story is, commercial jet passenger airliners are built "solid" like interstate trucks, they do umpteen flights over the Pacific, millions of air miles and then they pull the engines and rebuild them after so many flying hours.

Military fighter jet engines are more like Formula One race engines,. They run at vastly higher temperatures and pressure ratios, and consequently need far more preventative maintenance.
The exhaust turbine blades really suffer hell in a high thrust to weight military engine, and are made of particularly hard, tough, high temperature alloys that can withstand the conditions.

The individual blades, and exhaust turbine shaft are made hollow.
Air from the final compressor stage cools the exhaust turbine blades by blowing relatively cool air right up through the hollow exhaust turbine blade, and out through tiny pin holes arranged all over the blade surface.

That works great, but the time comes when your pitted and eroded turbine blade needs to be either rebuilt or replaced. Replacement is very expensive.........

The blades can have new material deposited to build up the surface, but that blocks the incredibly fine holes. So you need to re drill the covered holes in the exact same positions.

That is extremely difficult, because the blades are complex compound curves, and the hole diameter is measured in MICRONS, they are that fine. And the blade material resists any kind of mechanical drilling, it is so damned hard.

Solution. You place the blade in a multi axis CNC machine, and zap it with a solid state infrared laser, with optics to concentrate the beam down to an incredibly small diameter.

When we started that project, Pratt and Whitney were the only people that could do this, and in time of a serious war, shipping military jet engine blades overseas is not really a sound plan to keep all your fighter jets flying.

So the Australian Defence Department decided to design and develop their own equipment to fully refurbish high performance military jet engines, and do it ALL within Australia with our own fully sorted technology and know how.

Many Americans glory in their military technology, but fail to understand how fragile it will be in time of war.

Suppose the only factory capable of making or repairing a certain vital part gets bombed to total destruction. That is the problem us Aussies are trying to get around, by being as independent as possible from overseas suppliers of high technology equipment.

There is a vast secret industry here, reverse engineering (mainly) US military technology, and we can now do a great deal of it not only a lot cheaper, but often better than the original.

 

[Boncuk]

The story is, commercial jet passenger airliners are built "solid" like interstate trucks, they do umpteen flights over the Pacific, millions of air miles and then they pull the engines and rebuild them after so many flying hours.

Are you sure about that?

Air from the final compressor stage cools the exhaust turbine blades by blowing relatively cool air right up through the hollow exhaust turbine blade, and out through tiny pin holes arranged all over the blade surface.

The (eighteens) final compressor stage of the Tyne engine (the one used in the C160) has relatively cool air of 500deg/C. Tyne doesn't want to use that for cooling of the compressor stage. Instead they use compressed air from the 10th stage at a temperature of 150 deg/C.

That works great, but the time comes when your pitted and eroded turbine blade needs to be either rebuilt or replaced. Replacement is very expensive.........

You should know that the engines of an aircraft don't even cost 10% of the system buying price. Avionics are far more expensive, though a lot smaller.

The blades can have new material deposited to build up the surface, but that blocks the incredibly fine holes. So you need to re drill the covered holes in the exact same positions.

Sounds to me like using recaps for car tires. Neither used in the GAF nor in the Lufthansa.

and in time of a serious war, shipping military jet engine blades overseas is not really a sound plan to keep all your fighter jets flying.

Don't worry about that. The aircraft get unservicable faster than the maintenance interval. (We're going down!)

Many Americans glory in their military technology, but fail to understand how fragile it will be in time of war.

Oh, I didn't know the Australian military technology is less fragile.

Suppose the only factory capable of making or repairing a certain vital part gets bombed to total destruction. That is the problem us Aussies are trying to get around, by being as independent as possible from overseas suppliers of high technology equipment.

Good to know that you have more than one factory. I'll update my target map on occasion.

There is a vast secret industry here, reverse engineering (mainly) US military technology, and we can now do a great deal of it not only a lot cheaper, but often better than the original.

With other words: Copy like crazy! Does Australia have own developments besides the kangaruhs?

Boncuk

 

[Nigel Goodwin]

Off topic crap deleted - moderator.

 

[Boncuk]

Off topic crap deleted - moderator.

Thank you for your understanding.

Boncuk

 

[HiTech]

Off topic crap deleted - moderator.

Heh, heh.... lol .... jolly good show! It was turning into a pissing contest anyway.