PLANNING FOR THE WIND TUNNEL TEST OF THE 1903 WRIGHT FLYER
by Susan Lee
October 16, 1998 I have been able to attend the planning meetings for the upcoming wind tunnel test and I would like to share some of the concerns and preparations that are being addressed by the engineers planning for the test. In some ways this test is very simple compared to many of the tests done here at Ames Research Center and that is good because it means a little less work, but it surprisingly presents several challenges as well. One concern is that the model is made of wood and cloth. Since the 80' by 120' wind tunnel draws air in from the marshlands of San Francisco Bay, and since March is frequently rainy, the air in that tunnel might be wet. Chances are good that the untreated model would get wet and that would affect the data. Presently we are planning to hold the test in the 40' by 80' tunnel. This air will be drier and nice for another reason, you don't have to climb 3 flights of stairs to get there! Some of you may have seen the photos of the model in the hangar. Did you know that this hangar once was the home of a huge dirigible. Since its a historic hangar, it's a good safe place to keep a bit of history, the model of the 1903 Wright Flyer. In the photos you can see that there is a dummy on the model, or did we fool you into thinking that was really Wilbur Wright? Do you think the dummy will sit on the model in the wind tunnel? It will. This will simulate how a person lying on the plane will effect the airflow. I asked if the dummy weighed as much as a real person and found out it doesn't. To simulate the weight of a real person Pete Zell the test engineer told me they would throw a sack of potatoes on the model. At first I wasn't sure if he was kidding but he was. They will use some weights that will produce the proper weight for the test. Since there won't be a real person flying the plane, the engine and the wings, and the canard and the rudder will have to be controlled remotely. The AIAA members have built a console that will control them for the test. They decided to use an electric motor for this model (You know that the Wright brothers engine was a gasoline engine.) The instrumentation engineers are trying to plan for this. They think the engine might make noise. Not the kind you hear but the kind that will effect the data from the test. At you house if someone runs the blender or the vacuum does the TV picture get fuzzy? Well that's similar to the effect the engine might have on the data. Of course they will find a solution to this problem if they need to. Meanwhile the balance is in the calibration lab. It will be tested to make sure its measurements are accurate and can be used at the most extreme measurements that will be taken. When they take the Wright Flyer back off the sting, they will remove the sensors that will be used to make measurements during the test. These will be calibrated too. I hope to share more with you about the preparations going on. The engineers and researchers working on this job have signed up because of their interest but in the meanwhile they are all working on four or five other projects. When they are too busy to share some of their stories I'll do my best to fill in.