Turbo Jet homebuilt model engine

Originally designed in 1965 as an engineering student project. The idea being that function follows form using off the shelf inexpensive parts. See pics at following link: http://s805.photobucket.com/home/Turbojetdave

The Rebel turbo-jet Engine




1. Designed by David C. Chovanak as a project in pre-Engineering Frsehman student @ Nevada Southern University in Las Vegas, Nevada. (Now UNLV)
2. . Blue-print completed March 1965, construction August , 1965 - February, 1967.
3. Parts were derived from off-the-shelf components. Design philosophy was, " function follows form. " For example, the 'compressor' was a Hoover 6000 rpm hand held auto carpet cleaner vacuum unit, the exhaust guides and turbine was built from stainless steel apple core slicers, the mainframe, from the Handi-butler accessory kit of a Kirby vacuum system. The combustion chamber is a hardware funnel and a family size tuna fish can and asbestos tape. The bearings are copper alloy plumbing fittings. The shaft is shaft quality steel rod. The exhaust nozzle is a plated steel flour sifter and the exhaust cone inside is a flat head V-8 chrome oil cap Prototype named "The Rebel" after NSU athletic mascot, Chovanak was on the University track team '65-'66.

Description :
The Rebel is a 'paddle wheel' centrifical-flow compresed engine. Noisy, but can 'beat' a large volume of air at velocity. Air guides/ diffusers in the Kirby section slow down the velocity and increases the pressure so that the combustion chamber can further raise the pressure so that the gases then exit or "jet" out the back, turning a turbine connected to the forword compressor by the shaft which continues what is termed "The Brayton cycle." as opposed to a piston engine's "Otto cycle." 'Continuous flow' V 'stop and go' Fuel is that of "forgiving" acetylene gas.
Due to the quality of the metals in the "hot section" cooling is used to take destructive heat saturation away from the internal combustion chamber as well as the turbine guide blades as well as the turbine itself.
Jet engines 'love' mass, therefore as the water phases-expands into steam that will add to the thrust of the gas-jet. The engine is lubricated by oil under pressure and poured front and rear babbit bearings allow a slight leakage to aid in oil flow. At the rear this will also aid in heat removal of the turbine. Oil is 5 wt synthetic with an additive called "Energy Release." Starter is an electric high rpm motor 9-12 volts DC. with a reheostat.
In the exhaust cone is a flame holder which will combust additional fuel sprayed in at the turbine to produce "afterheat" or in other (American) words, an "afterburner" and much more roar!
There is a great amount of unused air available for further combustion and this will further raise the final tally of the 'jet' in an area that is not so heat-critical, perhaps by 30%. Therefore a 10 lb thrust would finalize as 13 lbs!

In essence the reaction is more akin to a rocket moto, and the fuel used is also 'rocketing' along the pipe line, so in full size jet-engines the afterburner is of short duration for emergency use, like getting a heavily laden plane off the runway and up to cruising levels where the engine can then sustain flight and fuel.

The Rebel weighs in @ about 5 lbs. Start up procedure is thus for thrust: 1. activate CO2 gas cartridge to pressurize the water / oil tanks to 10 lbs. 2. energize starter slowly until engine is @ 6000rpm. 3. turn on water control flow valve and place hand in rear to ascertain a cooling mist . 4. light the fire by activating a model T auto coil to excite the small spark plug as the fuel is slowly allowed to the spray nozzles. 5. a mirror placed to rear of engine 4ft back will allow the operator to observe the flame pattern, should it advance thru the turbine blades, the throttle will be retarted to 'pull' the flame back into the combustion area. Too much flaming is called a "hot start" and will destroy the life of the guideds and turbine. In early days of jet engine usage, the tail pipe temperature guage was carefully monitored by operators and a limited # of "hot starts" were allowed before the engine had to be overhauled to replace the 'over cooked' components. Some times things just flew apart. 5. advance the throttle- watching the mirror - until max rpm is reached, 35.000rpm. 6. Hit the afterburner fuel feed.
In respect for the high energy contained in the rotating patrs within the Rebel, under NO circumstances be standing around the engine, stay to the front of the air intake.
7. Shut down : turnoff the fuel as the engine spolls down to near stoping place a the blower fan to the intake to take down the temperature of the components in the hot section for 1 minute, or until the exiting air flow feels about room temperature.
8. Have a beer!

Category:

Science & Technology

Tags:

• turbo
• jet
• engine
• water
• cooled
• hoover
• vacuum
• compressor

[Batgoldfly]

Mechanical Engineering instructor and professors from a western university department wrote:

1. "It is quite impressive."

2. "I was impressed with its design."

3. "I'm impressed with your ingenunity and amazing use of a variety of components to build a working prototype engine."

[thegreentrader]

I love it. This kind of creativity is what makes engineering so much fun.

[hboy007]

the approach is really lovely and inspiring, congratulations to the nice video!

[toothfairy898]

Congratulations, you must be a darn good dnder. 46 yrs ago -no Dnd existed, but a fresh, whole pg full scale plan did in draftsman's ink.. No tea stain involved. Oxidation and acid content inherent in 1965 paper works it's toll over the decades.

[paintballingguy]

I play Dnd, I also make props for my campaign. The Maps I make look exactly like his "45 year old plans". Tea stains and edge roughing.

Now lets see it work.

[farn1991]

@Batgoldfly

I'm very impressed the way you think :)

People do it very different here in my country.

All lost in capitalism and money,

They don't even sure what are they study for.

[brjema1]

that is wicked cool. it always impress me to see what people can do with remants and little cash that our goverment gladly throws millions ,billlions at. when it can be done quicker and cheaper and still be safe and cutting edge, just think back to the industrial revolution. most of the stuff we take for granted originated in someones back yard shop

[Juandariorsr]

That's fantastic, I can wait for the video where you fire it!!!!

There is no engineering without ingenuity!!

[coffeecuppepsi]

mate youre awesome!!! cheers from down'under

[flaps20check]

in aircrafts using turbojet engines is there a bypass area? i think that all air passes through the holes

[Batgold]

@flaps20check

hello, 90% thru liner, 10% to rear of liner bypass to cool guides and turbine.

[steidl001]

You're a true maker! Love the idea. Projects like yours are what literally keep us moving forward!