Re: YASim prop discing and turboprop engine

Hello Andy

  I see. The effect we actually would like to demonstrate to the students
is that when the airplane flies with power on at the near stall
condition, the lost of a single engine at the low altitude is more
dangerous, then the lost of both engines, because the single engine lost
would result in a single wing stall from which the airplane is very hard
to recover. Do you think thrusters approach may help in this situation ?

If not, do you or anyone else may be know if the effect of the prop flow
on lift can be simulated with JSBSim ?

Thank you

Regards,
Oleksiy

> Oleksiy Frolov wrote:
>> Would it be possible to overcome this limitation by dynamically
>> altering a lift coefficient separatelly for each wing, or in the
>> worst case, using the spoilers ?
>
> Not without major surgery, unfortunately.  The Right Thing here would
> be to model inter-object effect using a flow field for every object
> (lifting surface, fuselage, prop, etc...)  producing aerodynamic force
> and use it in a feedback mode to calculate actual airflow at each
> point.  That's going to be complicated and slow.
>
> Modifying the wing (or other surface) coefficients directly is
> probably not a great idea, as those are generated by and intimately
> involved in the solver computation.  You could get the performance
> effect you want only by making the solver input numbers a lie.
>
> If you want a special purpose hack (er, "solution") for this aircraft,
> one thing you could consider is using a <thruster> object in the wash
> area of the wing, pointing it appropriately, and adjusting its
> THROTTLE input based on engine power and airspeed using a little
> Nasal.  This would still need to be set properly at solution time
> (when Nasal is not available), so there's significant complexity.  But
> you can make the solution as accurate as you want.
>
> Andy
>
>
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