How do windy/gusty conditions effect the quality of an outdoor jet ?
The first full size L-1 VWT at Appalachian Amusement Center is located in an area that is often very windy or gusty in the spring. As of the middle of March 2004 it has been windy or gusty half
the time we have operated, and very windy about 1/6 of the time. Our 50 foot wide building is located about 35 feet to the south of the jet and extends about 30 feet above the net. The building surely helps to block
winds, especially since the prevailing wind direction is usually from the south. We have also operated when it was very windy/gusty from the north. Our experience is that the jet is never effected below about 15
feet above the net, or 22-25 feet above the exit. Strong gustiness rapidly degrades the jet above 25 feet above the exit, but does not seem to effect fan speed or vibration. Since most fliers will stay below 15 feet
above the net, atmospheric wind does not seem to be a problem.
In February of 2005 we flew when it was gusting to a measured 31 MPH from the West. This was more severe than what we had experienced before we had
our weather station with it's anemometer. During the peaks of these 31 MPH gusts the wind is affected just 8 feet above the net. This is something a beginner probably wouldn't notice, but for a person flying higher,
or doing radical maneuvering near the edge of the jet, it can be exciting. Our RPM and the airspeed are not affected by the gusts. Remember that 8 feet above the net is actually 18 feet above the exit of the machine
itself. This is great performance.
Competing designs are greatly affected by windiness and gusting. With a more protected jet, or a lower net, even these severe gusts would be no problem.
An L-1 located in an
extremely windy environment will benefit from some specific modifications to the intake area, and structural blocking of the jet.