flyingcheesehead
Touchdown! Greaser!
I've always understood that a turbonormalized aircraft engine is equivalent to a normally aspirated engine, but has the turbo hardware added to allow it to maintain sea-level MP to a higher altitude, but would normally be used to simply cruise at a power setting similar to a normally aspirated engine (say, 23" and 2300 RPM), but at a higher altitude.
Of course, a turbocharged engine is designed as such, uses a lower compression ratio and a higher MP (e.g. 7.5:1 and 40") to do its thing, and that higher MP can also be maintained to a higher altitude, and the power settings are of course different, with a normal cruise being maybe 32"/2400.
As regards fuel flow, it seems that a turbonormalized engine's fuel flow should be roughly the same as it would be at a lower altitude - 23 squared at 7,000 should result in the same fuel flow as 23 squared at 17,000. Right?
But in reading an article about the Mooney Bravo (the turbocharged version of the Ovation that I fly), I'm wondering if the turbocharged engine's fuel flows are going to be significantly higher - I take off at 25 gph and cruise at 12 (usually at 23"/2200). The article talks about a takeoff flow of 29.5 and cruise flow of around 20 gph.
The Ovation I fly has a 280hp Conti IO-550. The Bravo has a 270hp Lyc TIO-540.
Why does the Bravo have such a high fuel flow? How much power is really being developed at these burn rates?
Of course, a turbocharged engine is designed as such, uses a lower compression ratio and a higher MP (e.g. 7.5:1 and 40") to do its thing, and that higher MP can also be maintained to a higher altitude, and the power settings are of course different, with a normal cruise being maybe 32"/2400.
As regards fuel flow, it seems that a turbonormalized engine's fuel flow should be roughly the same as it would be at a lower altitude - 23 squared at 7,000 should result in the same fuel flow as 23 squared at 17,000. Right?
But in reading an article about the Mooney Bravo (the turbocharged version of the Ovation that I fly), I'm wondering if the turbocharged engine's fuel flows are going to be significantly higher - I take off at 25 gph and cruise at 12 (usually at 23"/2200). The article talks about a takeoff flow of 29.5 and cruise flow of around 20 gph.
The Ovation I fly has a 280hp Conti IO-550. The Bravo has a 270hp Lyc TIO-540.
Why does the Bravo have such a high fuel flow? How much power is really being developed at these burn rates?
