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Old 04-22-2009, 11:15 AM   #3 (permalink)
theunchosen
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Quote:
Originally Posted by jesse.rizzo View Post
Can you run a turboshaft engine on unleaded automotive gas? Because I don't know too many people willing to own a car that requires Jet A.
actually that is one of the special perks of using a turbine engine. as long as the medium is heating and expanding(or really just has lots of heat energy) you can use it.

You can burn biodiesel, diesel, gasoline, a-fuel, 103, 101, 93, 91, 87, alcohol, propane, methane, SVO(filtered only) and wood/coal if you can grind it up fine enough to get it through and injecter. The US military tested this out on their Abrams A1 power pack in the event the vehicle was not able to be re-suppled what it would need to stay in the fight. If commercial gasoline is available it will burn it and there aren't really penalties for things like pre-ignition because the uel typically ignites about 50% through the combustion chamber so "pre-ignition"(igniting before the intended point in the cycle) radically increases the amount of power available.

The reason jets run A-fuel(usually 110 if I recall correctly with some other additives for turbine benefit brand depending) is because it gives the best p/w output(1.51 hp/lb while normal fuel will deliver something like 1.35-1.45 hp/lb).

Also Turbine engines have nowhere near as many moving pieces. A turbine has one shaft that connects(in jet engines its a little different) the radial compressor and the turbine blades, injectors, a spark plug thats used 1-5 times then switched off and thats it. A basic cylinder engine has a shaped crankshaft, 4 rods, 4 piston heads, 4 cylinders, minimum of 8 valves, 4 injectors, 4 spark plugs that ignite every 4rth rotation. The injectors on the turbine inject at steady flow while the cylinder has to inject in pulses. Less complicated/fewer moving pieces means fewer things can go wrong or break.
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