Vivian Meazza wrote:
> With these values
>     eng-power="1140"     eng-rpm="2850"
>  cruise-power="2850"  cruise-rpm="1359"
> takeoff-power="1100" takeoff-rpm="1359"
> YASim appears go into a loop and provides no output.

These settings don't make much sense in combination.

The "eng" setting is a maximum power (at standard sea level) for the
engine without supercharging.  In this case, the normally aspirated
engine develops 1140 HP at max RPM.

The "cruise" numbers are used to fix the propeller's maximum
efficiency peak.  The propeller you are using wants to sink 2850 HP
(more than double max sea level power) at less than half (!) of the
engine's max RPM.  Even with 4x supercharging (which sounds kinda high
to me, but I'm not an expert), that's just not going to work.  Are you
working from POH numbers for this engine that might be typoed or

The "takeoff" values correspond to the power and RPM developed by the
aircraft at max throttle and zero airspeed.  It's there because
propellers have funny, non-linear behavior in the very low pitch
regime (when the blades are partially stalled).  The default model
produces strange results here, so the FDM allows you specify a clamp
to match real-world behavior.  It's not important to the solver, or
for in-flight performance.

I'll look into the apparent infinite loop behavior.


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