Gas Turbine Engine
I got this engine from Michel Kooy AKA Pyromaniac in exchange for a Nimbus engine. In fact, I traded the Nimbus for the T62 and another GTP30-67.
The T62T-32 is the prime mover in the Solar Ground Power Generator (GPU) type EMU-30/E which is rated at 60kW 400Hz. The generator is enclosed in a large (well, large in terms of my mechanical handling equipment) soundproofed aluminium enclosure, the overall weight of which is a colossal 430kg....which is a bit of a bummer, since the reason for trading the Nimbus in the first place was that I was too heavy for me to move very easily (all of 300kg)
The image above shows the EMU-30/E ready for its first run. On the bench beside the GPU is the fluorescent orange control box and the laptop logging the 'flight data' from the Picologger. The manufacturer's original electronic controller was burnt out on this unit, so I designed and built this replacement. Behind the control unit are the two decade resistance boxes with which I attempted to tune the Proportional/ Integral speed controller built into the control box. The control box connects to the original GPU instruments and the T62 engine harness through an umbilical and a relay box.
Having succesfully tested the engine and (slightly less succesfully) the control box, the engine is pulled from the enclosure. There are a lot of other interesting an useful parts in the enclosure. Some interesting aspects of the enclosure are the intake silencer/particle separator and the exhaust muffler.
The yellow part of the engine is the 60kW 400Hz alternator (or generator). As you can see by the way the engine is hanging, the alternator is heavy (about 50kg).
Some views of the engine, with the generator removed. The gearbox is the biggest and heaviest part of the engine, the turbine itself is very compact and relatively light at 64kg.
I've cleaned the engine as well as I can without actually completely stripping it down. Does anyone know of a perfect way to clean aluminium castings ?
Here is a cutaway (58kb) of the engine. This is very similar to the GTP30-67 is its design, with the turbine and compressor back to back on a cantilever shaft protruding from the gearbox. The bearings for the turbine are therfore remote from the hot gas, and are cooled and lubricated by oil mist circulated up the hollow rotor shaft.
I think the time has come maybe to stop playing with the engines and put this one to work....I wonder ?
At around 100shp rating, it is tempting to consider a wheeled vehicle application for this engine. Mating single shaft turbines to wheeled vehicles is tricky. The turbine is best at constant speed, and near 100%N at that. The efficiency and output power drops off drastically at shaft speeds below the rated design speed.
Engaging a clutch manually, while attempting to keep the turbine speed constant would be fun - for a while. Maybe a bit ugly, but a belt drive constantly variable transmission (CVT) and a properly designed centrifugal clutch would be an interesting combination with this engine. After all, snowmobiles use this technology, and they are not ugly, or slow ! The engine would have to be electronically controlled still, to prevent too much droop in the shaft speed, and also to protect against turbine overtemperature.Thanks yet again to Ian the initial information on this engine, his web site has more interesting stuff on this and many other gas turbine engines.
I found the manual for this engine at Aerotecdata, they carry a large range of manuals for engines and airframes.
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