Aerospace Team ONLINE

ADTO # 73 - August 6, 1999

PART 1: Upcoming Chats
PART 2: Project News
PART 3: Preparing to Collect Data

UPCOMING CHATS

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

PROJECT NEWS

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

This a special summer contest for Aerospace Team Online. This contest is
open to all students between the grades of fourth through twelfth. The
grade categories are as follows:

      4th through 8th
      9th through 12th

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

Checking out the Model

By Mina Cappuccio

July 28, 1999

By the end of the day Wednesday the model was installed in the wind
tunnel. The wind tunnel test section and control room are on the second
floor at the twelve-foot pressure wind tunnel.  Using a crane, the model
was taken off the bipod in the model prep room and laid on a long flat
table on wheels.  The model was brought to the second floor using a huge
elevator.  The table was rolled over to the front of the test section.  A
crane was used to lift up the model from the table, moved and lowered over
the bipod for attachment.

Early in the day on Wednesday the SDS (pronounced suds) data reduction
program was installed. There was a bunch of trouble shooting by the data
technician to check out the program.

Most of Thursday and Friday, was spent hooking everything up.  There is a
patch panel where all the connections to the data system are made. They
had to connect the balance wires and the three thermocouples on the
balance. The digital angle sensors in the model had to be hooked up and
calibrated. There are two of these sensors in the model, a primary and a
backup instrument. They did balance checkloads by adding weight and did
angle checks by pitching the model and calibrating the sensors.  These
final checks can only be made when the system is connected up in the wind
tunnel.

While the instrumentation techs were making all the connections between
the data collection system and the model, the mechanics in the wind tunnel
were getting final model parts on like the vertical tail and nacelles,
model clean up and patching holes with a material mix of wax and clay.

On Thursday we had a little bit of a scare. When the mechanics were
cleaning up the model, there was a part of the nose that was missing.  We
built a new nose for the high mount canard configuration. One of the
mechanics came to me and said, "Where's the little nose tip?" He was
looking for this part which is a little cone that is very short, about
three to four inches long and two to three inches in diameter. I knew that
the machine shop was using it to make sure it fit with the new nose part.

When they tried to remove the cone from the new nose model, they couldn't
get it off. Somehow when they had attached the nose tip to the new part it
was jammed and they couldn't get it off. Every time they put a wrench to
the part to take the screw out the wrench would bend.

Finally they took the part to the metal machine shop that works on big
jobs, and has heavier equipment. They welded on a drill bit to the head of
the screw and then they welded the wrench to the bit. This way they
planned to get more torque on the screw. But when they tried this and the
wrench broke right off at the weld joint.

They welded it again and happily this time the screw came right out.
Examining the screw you could see that it was all galled up. The hole
probably had dust or tiny particles in it which caused the tight fit. We
put the cone on the old model Thursday afternoon.

On Friday the model was pretty much ready but we were having problems with
check out of the instrumentation system for pressures.

On Monday morning we had a debriefing meeting on the test. We heard that
there were still problems with WICS and model pressures, BLAMS needed to
be checked out, turntable limits for yaw needed to be set and needed to do
pitch angle checks. The model was ready but the instrumentation was not.

The WICS and model pressure instrumentation problem was due to leaking.
It turned out the C1 solenoid needed to be replaced. To calibrate the
pressure modules, the module has a sliding switch in one position you can
make calibration measurements and in the other position you can make the
test measurements. To slide the control there is a switch.  In calibration mode it
feeds air to the module at a certain pressure so that the ports, or
transducers, read a certain level. Because of the solenoid leak the switch
wouldn't slide. Once they figured out that was where the problem was
coming from they replaced the solenoid.

Then they had to make leak checks on all the Tygon tubes, and discovered
leaks in the pressure control tubes which were replaced or repaired as
needed. Now both the model pressure system and the tunnel pressure system
have been calibrated.

The length of the wires on the balance thermocouples was to short to reach
the patch panel, which was at a different distance than the panel they
used for the last test. They had to extend these lines.

Hopefully next week I can report that the tunnel is running and I have
collected the data on wing one and compared it to the data from the last
test.