David Luff wrote:
Yes, I have got too many. This is the friction that was applied only when starting; I was making it permanent but haven't finished with it. Do you agree that it should be permanently in? Does a constant torque sound about right? That sounds more likely than constant power (which means decreasing torque), to me. Conventional friction would give constant torque; I'm not sure how oil and air viscosity behave, but I'd expect the torque to increase at higher speeds rather than decrease.It looks to me like you've got 2 too many curly brackets in doEnginePower, although I could be misunderstanding what you're doing there.
I don't understand how it could have worked with no resistance implemented. A propeller hardly provides any resistance at low speeds, so I would have thought you would have needed to tweak the developed power down to almost zero at idle.
Ah, thank you for explaining this. I had not understood the mapping onto manifold pressure and the power correlation. It certainly sounds like the power correlation is the thing to un-tweak instead!What I am concerned about is the throttle minimum being set to 0.2. ...
This puzzled me: the manifold pressure seems to be modelled as (for a given throttle position) independent of speed. When a real engine is running fast and you cut the throttle, the fast air flow will cause a very low manifold pressure which will then rise to its new steady value as the engine slows down. Without this effect, throttle changes will not take effect as quickly as they should and the speed variation with load changes will not be right. Maybe the effect is too small to be important?
I might be attempting too much here; I know how car engines work but don't have data to work from (or a lab), and I don't have experience of modelling them either. I will tread carefully and check with you again when I make some more progress.
- Julian
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