swampyankee
Chief Master Sergeant
- 3,982
- Jun 25, 2013
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A gas turbine with the same power as a regular Chevrolet Corvette engine would be considered a microturbine!
I'm just glad there are some folks that aren't stuck in a box, else inventions and refinements would be nonexistent. Even your precious turbine would not have come to fruition. I like how the one fellow above says they are way more efficient than piston engines, how come my little 50 mpg car doesn't use one?
Outside the box, there are dragons.
Where does that take us? We still don't have supersonic propellers, and probably won't, at least not with the power levels we can supply.
. Maybe.
Aero engines most certainly DO (effectively) have displacement limits.
Bore size is limited by combustion considerations, and stroke is limited by the mechanical limit of the resultant "mean piston speed".
How many of these "units" of acceptable bore/stroke can be accomodated is strictly limited by
1) The aircraft design weight (eg range and general performance), of which the engine is (in the case by example of mk1 spit) 33% of the total unloaded weight.
2) The frontal area, which will be dramatically altered by the choice of Vee, Flat, Radial or In-Line radial (eg Jumo222) layouts.
3) Cooling, experience has shown that anything longer than a twin-row radial is exceptionally difficult to cool properly, this limits displacement.
4) Vibration characteristics, for an in-line engine, anything longer than a V12 will produce very unpleasant torsional vibrations, which DB discovered
with the DB609 (a V16).
As for why designers were not trying to use high performance automotive units as the basis for aero engines, this is also incorrect, as my last post
illustrated with the RED diesel aero-engines all based on Toyota Formula 1 engine technology. Auto-Union was also doing Aero-Engines in WW2,
these did not fail because of any intrinsic problem with the concept. Its rather obvious that Dragster engines are a pointless comparison.
Essentially I dont really understand either of these threads, which were supposed to be about how you would make the best piston engine, but
have decended into a pretty fruitless turbine/piston mud-slinging contest - which is about as useful as arguing about if apples are better than carpets.
This thread could have been very interesting, but has been basically ruined. Why not start a new thread and call it "Pistons or Turbines" ?
They didn't work well then and nothing since then suggests they are going to work any better.I guess you haven't studied that very well. They did supersonic props in the 50's.
I guess you haven't studied it either. How about Mach 1.2 ? All in the 50's all old school tech if they did it then just think now. Also I guess you haven't heard about the latest engineering that is working on quiet sonic booms for small supersonic business class jets. Yeah this is modern times we are in now, not in the 1700's .Chances of a plane driven by propellers going supersonic in level flight are also zero.
From Wiki.I guess you haven't studied it either. How about Mach 1.2 ? All in the 50's all old school tech if they did it then just think now. Also I guess you haven't heard about the latest engineering that is working on quiet sonic booms for small supersonic business class jets. Yeah this is modern times we are not in the 1700's now.
I guess you haven't studied it either. How about Mach 1.2 ? All in the 50's all old school tech if they did it then just think now. Also I guess you haven't heard about the latest engineering that is working on quiet sonic booms for small supersonic business class jets. Yeah this is modern times we are in now, not in the 1700's .
That would not make sense to say they flew the propeller assisted like that, the other engines were part of the plane and helped it get to altitude for the test flights as well as for safety . If they were wind milling it then there would be no need for an engine to power the prop.Let me guess you are talking about the XF-88B? If so you might want to study it a lil more. Sure it had a turboprop up front driving a propeller, but it also had 2 turbojets. That's how it achieved Mach 1.2 in 1953.
That would not make sense to say they flew the propeller assisted like that, the other engines were part of the plane and helped it get to altitude for the test flights as well as for safety . If they were wind milling it then there would be no need for an engine to power the prop.
The Fighter Writer: Ron Easley's Aviation Blog: Supersonic Propeller Research: The XF-88B Voodoo