MIDWAY THROUGH THE TEST

By Mina Cappuccio

August 18, 1999

We began testing the Wing 3 configuration on August 4th. We have obtained lots of data. We ran Wing 3 with zero flaps and with tails on off. We use zero flaps as a benchmark to measure our increments from. We tested the optimum Leading Edge and Trailing Edge configurations based on the TCA-4 test. We ran that with tail on and tail off then we tested it with different tail angles (stab angles). The tail rotates manually and we can test different rotation angles.

Then we did a bunch of performance and stability and control (S&C) runs. Performance runs are always pitch polars with a Beta or sideslip angle set to zero. A pitch polar means we get data at different angles of attack. This was done at low and high Q, where Q stands for dynamic pressure. It directly correlates to Reynolds Numbers (RN). Low Q means low RN and a high Q means high RN. This part of the test goes back to our test objectives. Our first objective was to try to figure out what the best leading edge and trailing edge flap configuration was and to try to figure out what the Reynolds Number effect is on the best flap configuration.

This is Pat Schumacher. She has been helping review the data.

We also did a bunch of stability and control (S&C) runs. These are usually Beta sweeps at a constant angle of attack. Or angle of attack sweeps at a constant beta. These runs look at the lateral and directional stability, including, pitching moment, rolling moment, and yawing moment.

On the video monitor screen you can see what the control room sees, in this case the oil painted on the wing before a flow vis test.

For the plain flap optimal configuration we did flow visualizations for three angles of attack. To do this we painted an oil and tempera powder mixture on the wing and then took pictures of the patterns on the wing made by the air flow over the oil.

We tested what we thought would be the optimum configuration and then we started changing the deflection angle of the outboard leading edge. Then we started playing around with the trailing edge deflection angles to see if there was an optimum deflection angle. This was an incremental step by step process where we tried to optimize the flaps. In the end we found that our estimate of the best outboard leading edge was correct. We also found a better deflection angle for the inboard leading flaps. This was one of the new flaps we had built especially for this test. This was good news. Most of this was tested at low pressure. Then we did more low and high Reynolds numbers (Q) testing on the best model shape and more tests with tails on and tails off. Then we did more S&C testing and then we were done up with the plain flaps.

From our test objectives we had planned to look at three different configurations: plain, variable camber, and sealed slat to optimize the shape of the wing at the Leading Edge for different deflection angles.

Next we were planning to do trim runs with the canard, but we skipped that because we are behind schedule and if we have to cut some of the runs at the end we might cut these.

Now we are in the middle of the optimization of the variable camber leading edge flaps. We started this on Friday, August 13, 1999. So far we have figured out what the best outboard and inboard flaps are and we have done some flow visualization studies. This information will go to the CFDer's, computational fluid dynamic researchers. Throughout the test plan the runs have different researchers in mind. Just this morning we finished the trailing edge flap study and picked the best trailing edge flap.