Military Turbine Engine Generator MEP362A repair

[nexus]

Hi All,

Thought I'd share a little electrical repair I did on a Generator Electronic Control Module (GECM) out of an MEP362A turbine engine genset. This is a 28 volt 10 kw APU designed for powering small aircraft on startup.

Pictures and a vid of some sweet turbine engine sounds here: https://neonkev.com/2021/08/01/military-jet-engine-generator-repair-mep362a/

Enjoy!

[TurboTom]

Thanks for linking your web site on the MEP362A! That's (one of) my business(es) by the way, converting, maintaining and repairing ex-military genset turbine engines for applications in experimental / ultralight aviation, and recently also designing such units.

Regarding the maximum power output of the Tiernay TT-10 though, I've got to disappoint you. It's correct, someone put the statement into the public that this unit is capable of 150hp, but that's far from reality. The TT10 with its comparably small compressor inlet, relatively low RPM and only three main burners won't produce more than 60hp. Maybe this "Someone" just copied the figures of the Solar T-62T-32 engines that are also utilized in gensets (EMU-30/E) and usually go into "our" little helicopters...

If you need further manuals for the MEP362A, I've got several in PDF format, including detailed schematics of the control boxes, that I can provide. Just send me a PM if you want them... 

Anyway, I enjoyed watching your video clip a lot, I really love how the exhaust flap gradually rises upon startup of the engine. These machines have something addictive, there's no thermodynamic engine of comparable simplicity (from a working principle point of view) with a comparable power density. And you can really feel that when firing up such a unit...

Cheers,
Tom

[nexus]

Glad I had the opportunity to work on something cool like this MEP and share! That's a neat business you're in Tom.

Appreciate the correction; I'll have to fix that exaggerated horsepower claim. I was dubious myself about the 150 horsepower figure. 150 HP is roughly 110 KW; that would be abysmal efficiency for a 10 KW electrical rating, even with considering the intrinsic low efficiency of smaller turbines and mechanical to electrical losses.

Even for a such a small engine with exhaust baffling it has quite a bark. You have to give guys like Frank Whittle credit for envisioning such a concept in an era where internal combustion was barely practical.

[nfmax]

Back in the 80s, I spent some time working on the periphery of aviation. I didn't know it at the time, but one of my colleagues had spent time (as an apprentice, I think) with Whittle at Power Jets Ltd. I did know that another colleague was a friend of the Sopwiths...

[Renate]

Nice!
Could you give us a high-res of the diagram on the inside of the cover?
Thanks.

What's the smallest (turbine) APU out there?
I need 5W to charge my phone.

[Miti]

Very cool stuff!

[TurboTom]

Nice!
Could you give us a high-res of the diagram on the inside of the cover?
Thanks.

What's the smallest (turbine) APU out there?
I need 5W to charge my phone.

Well, not really 5W but here's the smallest of my own designs, a half-way running prototype of a 5kW unit. If you've got a phone based on vacuum tube technology, this may be the power plant you'll need to use it. Yet, calling someone may be somewhat difficult due to the not quite "silent running" features of the power plant, and the fuel bill will by far exceed your cell phone contract expenses... 

[Renate]

Wow.
Are you using vegetable oil as a lubricant?
How much oil does it use?
Is that a tricky deal getting the machining so that it doesn't use too much oil?
I can imagine the noise.

Here's 500 Watts from a solid oxide fuel cell running on propane.
https://www.wattfuelcell.com/portable-power/watt-imperium/
It's 45dBA @ 3ft

For now, my 600 Watts of solar keeps me going fine.
And the noise level is acceptable.

[TurboTom]

Oil usage of this engine is neglible since there's only one labyrinth in the cold section of the engine, and that's pressurized with bleed air. I'm using genuine turbine oil for lubrication in a closed-circuit system (the rotor spins at 160,000rpm). The oil tank is the modified "hip flask", installed directly below the engine.

The engine is designed to run on plain Jet-A1 fuel or kerosine / paraffine (and that's what's actually stored in the veggie oil container... ). Since the combustor is of the vaporizing type, heavier oils and vegetable oils as fuel are problematic. Provided, a bigger combustor with a bigger volume is installed, bio fuel operation should be possible.

But anyway, efficiency is ridiculous. When I started work on this project, the best power-to-weight ratio was the main objective (you probably guess where the journey was supposed to go...). To achieve a half-way decent fuel economy, a recuperator would have to be added in order to recover some of the exhaust heat. Whatsoever, some 5kW of electrical power out of a 2kg (plus accessories) package is quite impressive.

Anyway, it's still a prototype and there are many improvements that would need to be applied to turn it into a viable product...