Engine fans

Attempting to make the outermost compressor and turbines spin was not a success. The engines are modelled in an object file, so I created a 48-blade compressor, and attempted to animate it.

There were two problems:

  • First, there is no dataref for animating jet engine stages. I fished through various discussions, following various leads and testing whether the dataref had a usable output. No joy. My options are to write a plug-in, or wait in the hope that a dataref will appear in X-Plane v9.

  • Secondly, having created the fan, I wanted to see how it would look in motion. I used the "sim/time/total_running_time_sec" dataref to simulate a number of speeds, and was singularly unimpressed with the result. Only when the blades were turning slowly did they look good, but at very modest rpm they appeared stationary, or wobbled to and fro in a highly unrealistic way. It's not even like a stroboscopic effect. I can see why Austin Meyer makes propellors become a spinning disk at quite modest speeds, and I am highly impressed with the work done by the Morten and Tom Kyler at the X-Plane Freeware Project for their 757.

    It was fascinating, but something I must file away for future developent. I can't be distracted by it any longer ...
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