By Mina Cappuccio
September 15, 1999
After the smoke and laser test, we finished up our force and moment data for the high mount canard. We completed those tests. Then we switched over back to the mid-mount canard to finish up some runs that we had left unfinished before. That was the end of the test. We had some time left over so we decided to do some additional trailing edge flap study runs. We took all our optimum leading edge flaps and did some more trailing edge flap optimization runs to see if we could find any combination of flaps that was better than the one that was the best in previous runs. It turned out that we could not fine a better combination of flaps. We finished running Monday of this week at ten o'clock.
Meanwhile, the technicians who had been working on the laser smoke screen test had been meeting with the Facility Manager and convinced him that they could produce better results with water vapor. They replaced the smoke generator with a water vapor generator into which they put water. They injected 7 gallons of water's worth of vapor into the tunnel. They also moved some cameras around to help in tracking the vortices. They moved the camera up to the top window so that it was looking straight down on the model, and it was on a pan and tilt unit so that they could pan the camera and zoom in on the vortex.
We brought the tunnel up, and it worked. It was much better than the smoke screen. It didn't pick up all the vortices that we expected to see. It picked up all the strong vortices and not the weak ones. What we saw was the void and the outer rings of the vortices.
Because this technique was more successful, we put the canard back on the model and did some running, and we made some interesting deductions. All we could see were the strong vortices. We would pitch the model to different angles of attack. Some times we could visualize the vortices and sometimes it would disappear. This also happened when we moved the canard.
This didn't make sense. The vortices should have been visible at most angles of attack. That was how we deduced that the water vapor was only showing us the strong vortices. We took some pictures and finished Monday. Then the mechanics and technicians began de-installing the model and packing up the parts. They will be shipped back to NASA Langley Research Center.
Now we have to finish re-computing data and then distributing it to the researchers at Boeing and NASA Langley. Then I have to summarize the data for the High Speed Research Program, which ends in September. This won't be very difficult since I have good documentation for this test. I also have to summarize my previous test, which was a high-speed test of the High Speed Civil Transport in the Boeing supersonic wind tunnel in Seattle. Even though I am feeling a bit of a let down from the end of the test, I have to keep going and get these reports done.
Today I got to go home and play with Misty and Tigger at lunchtime. That was fun! They seem glad to see me more often.