by HHS » Thu May 20, 2010 9:29 pm
Thanks Maik for the explanation!
I think I've found out why mapping of the engine rpm to the main rotor doesn't work correct with the code above.
It assumes that both n2rpms a summarized bevor applying to the main rotorshaft.
For a two-engine heli it would like that:
Both engines are connected per gears with main rotorshaft. The gears transmit the power of both engine to the main rotor shaft. The rpm isn't summarized.
When just one engine is running (due to failure; not yet started...), we indeed just have half power.
But the running engine has still full rpm, which are transmitted to the rotors. Means the rotor will run though with full rpm. But when we raise the collective the power will maybe not be enough to keep the needed rotor rpm alive. Depending on the single engine power the rotor rpm will drop quite fast.
For an Ec135 40-50% 2x are enough to hover. But in EMS-config, from a high platform it needs 2x 75% Power.
With failure on one engine the other can provide 128% for a short time, but 22% are still missing...
So we have still to find out now how we can simulate this.
Up, up and away