ADTO # 74 - August 13, 1999
Tuesday, August 17, 12:00 p.m. Pacific Daylight Time: Phillip Luan, mechanical engineer Balances used in wind tunnel tests tell engineers how the force of the wind affects the model. Phillip is responsible for making sure that balances used for these tests are extremely accurate. He also helps determine how electrical signals received during the tests are related to the accuracy of the balances. Register for this chat at http://quest.arc.nasa.gov/aero/chats/#chatting Read Phillip's profile and field journals prior to joining this chat. http://quest.arc.nasa.gov/aero/wright/team/luan.html Learn about the lab where he works at http://quest.arc.nasa.gov/aero/wright/tunnels/balcallab.html
We are following several aeronautics research projects at NASA Ames Research Center this summer and will be bringing them to you in the Fall, stay posted for more news. - - - - - - - Follow a Wind Tunnel Test of the Airliner of the Future Meet the people from NASA who have been planning and working this test. Read their compelling field journals as they surmount problems and the test progresses. Learn more about High Speed Research. The model is in the tunnel, and air is about to start blowing. Make a bookmark at http://quest.arc.nasa.gov/aero/events/hsct.html - - - - - - - Summer Air Travel Contest Only 18 days left to submit your entry!! This a special summer contest for Aerospace Team Online. This contest is open to all students between the grades of fourth through twelfth. For this contest, we ask students to help researchers here at NASA solve the air travel traffic problems. For more information go to http://quest.arc.nasa.gov/aero/events/contest
[Editor's Note: Mina Cappuccio is the NASA Ames research engineer on the low speed test of the High Speed Civil Transport Technology Concept Airplane model. Read her biography at http://quest.arc.nasa.gov/aero/team/cappuccio.html ]
THE TEST HAS STARTED
By Mina Cappuccio
August 4, 1999 On Wednesday, July 28, 1999 we had a shakedown run. We started the tunnel, pitched the model, took data and took the wind back down, just to see that everything is working ok. Starting Thursday morning, we started following the test plan. We started taking data. By 11 AM, we had taken data for three runs, and by five o'clock we had completed 13 runs. We stayed late so that we could do a model change at night. A model change means we actually change the shape of the model. In the middle of the day we put on the horizontal tail and at the end of the day we took off the horizontal tail and we changed the leading and trailing edge flaps. I remember Betsy, one of the instrumentation technicians from NASA Langley Research Center, left at six to have dinner with her uncle, and then she came back to finish the model change. We got five runs on Friday, including a couple of model changes. At noon we had Tom Trower, the NASA Ames Research Center photographer, come in and take some professional pictures. On Friday afternoon we began the big model change. This model change took all day, Monday, and Tuesday, to complete, including some work on Sunday. We are all getting a little tired now because we don't have enough people to support this test. We had to do a lot of checking of the data from the wing 1 runs during the model change to wing 3. Part of the big model change to wing 3 was to make sure there was continuity between the wing pressures and the ESP modules. Also had to leak check the pressures to determine which are good. I will get the results of the pressure continuity and leak checks and will use these results to plot the data. Actually Bryan from NASA Langley and Robin from Boeing will be doing a lot of the plotting. I have been busy getting things ready for the next configuration. I enjoy being involved in the full picture of the test. Some people think that wind tunnel testing is boring. I think that its because they don't know all the steps involved to make the data corrections and model changes. This is a big configuration change and requires two people to make the changes. While they were doing the model change, we were plotting the data from the previous model configuration (wing 1). The data looked a little strange compared to the data from the TCA-3 test. The drag polars, the lift vs. drag plots, looked about ten counts higher. I thought that it didn't seem right to get that big of difference from test to test. I started reviewing the data reduction equations. At this point we think the cavity pressures, or the pressures that get measured in the cavity of the fuselage, might be responsible. We discovered that these pressures weren't getting measured. We were making data corrections without these numbers and now we don't have this data to make the proper corrections in the data reduction. Since this part of the model doesn't change in the next configuration of the model, we will use the cavity pressures from the next runs and apply them to the runs for which we don't have cavity pressure data. Sometimes you must make corrections to your data after the fact. When you look at the data during the test, you can't compare it to the previous test, because the system can't handle that much data. Meanwhile on the home front my two cats are driving me up the wall. I left Misty and Tigger at my mother's house in Boston, while I was traveling back and forth to Seattle for my previous wind tunnel test at Boeing. My mom, has two cats, so all together there were four cats at her house. She can't stand them being cooped up in the house all the time, so she let's them out and they can walk around outside. Now that they are at home Tigger wants to be outside all the time. I don't want them to be outside cats, I want them to be inside cats. They can go out on the patio when I'm home but I don't want them roaming around in the neighborhood. But now when I open the door to the patio Tigger jumps on the fence, jumps on the other side, and starts roaming around. She does come back, but I am worried while she's gone. I notice she's getting closer and closer to the main street, which is very busy. One time I caught her climbing the olive tree; she climbed all the way to the top onto a teeny branch and then jumped on the roof. She jumps on everything! That's why I named her Tigger. When I got her as a teeny kitten she was bouncy and she's got stripes, because she's a tabby. Misty doesn't know how to jump but she's a crybaby. She wants to go where Tigger goes, so I have to open the gate so that she can follow. They used to be afraid of cars but now it seems as if they are more daring, getting closer and closer to the traffic. So I have to retrain them. I'm not letting them go out. When I get ready for work in the morning they are meowing at me! Even with all the aggravation, I am happy to have them home when I get home from work. I've been golfing and had a girl friend from Santa Barbara visit. I'm trying to stay balanced, even though I'm working hard. Next week I am going to focus on speeding things up. We need to take data and make the model changes go faster. We are running a couple of days behind. I will also be focusing on the data to make sure it's corrected for the new configurations.