February 12, 1998
[ Ross/Ames - 5 - 09:02:45
QuestChat with Ross Shaw
RE: [Susan/NASAChatHost] Good
morning everyone the chat with Ross Shaw is ready to begin!! Does anyone
have a question for Ross?
Good morning. I am looking forward to your questions. I think I'm ready.
- 6 - 09:03:46 ]
Ross, what was the most interesting thing about being a wind tunnel test
[ Ross/Ames - 7
- 09:04:55 ]
I think the most interesting thing is seeing the next generation aircraft
[ Ross/Ames - 9
- 09:08:31 ]
Can you say something more about that?
Well, I have been on wind tunnel test projects for the F-22 Raptor, for
upgrades to the F/A-18, for the Boeing 777, and even for the replacement
for the Harrier.
[ Ross/Ames - 11
- 09:15:33 ]
RE: [Susan/NASAChatHost] What
advice do you have for kids who want to be aeronautical engineers?
I would say take math and science classes, perhaps build model and/or
remote control airplanes. Most importantly, if you like airplanes try
to keep up with the what is happening in the field. I think if it is something
you really enjoy, go for it!
[ Ross/Ames - 15
- 09:22:31 ]
] Which was your favorite test?
I think my favorite test was when we were testing an F/A-18, which is
a Navy/Marine fighter. On this test we were using a new technology, pressure
sensitive paint, to determine the pressure distribution across the entire
airplane. This was fun because it was the first time this pressure sensitive
paint was used to get real data for a fighter airplane; it also was fun
because when the ultraviolet lights were shown on the plane, it made the
plane look pink, but ominous.
[ Ross/Ames - 17
- 09:28:21 ]
RE: [Parker/HomesteadHigh] Is it the longer
travel time of the air that goes over the wing or the lower pressure on
the air rushing over the bottom of the wing that generates lift
Lift is generated by a pressure difference between the upper surface of
the wing and the lower surface of the wing. The higher pressure is on
the upper surface of the wing and lower pressure is on the lower surface
of the wing. Therefore, it is the lower pressure on the lower surface
of the wing that generates lift. The air on the upper surface goes faster
because it has to follow the contour of the leading edge. The fundamental
equation that best describes this is Bernoulli's equation: P + 1/2V^2
[ Ross/Ames - 19
- 09:33:03 ]
RE: [Susan/NASAChatHost] Have you ever been
When I was in college there was a counselor in the Minority Engineering
Program who told me I should not be an engineer but a physical education
major. This was based on the fact that my resume had jobs that were sports
related and my gpa was not all that great. After talking with family who
believed in me, I stuck it out knowing I would be successful. By the way,
he did not return the next year as a counselor for the MEP. I did go on
to graduate school and have done well since.
[ Ross/Ames - 21
- 09:37:50 ]
RE: [Parker/HomesteadHigh] Can you actually
see the paint change colors under the different presures as the test is
performed? And is the paint allowed to go through many different color
changes or does it hit a max and stop?
You can't really see the colors change with the naked eye. There are special
ultraviolet cameras that digitize the image and a computer program interprets
the data. After a couple of minutes the computer will create a picture
of the pressure distribution on the surface of the airplane. There will
be different colors on the surface indicating where the low and high pressure
[ Ross/Ames - 23
- 09:43:22 ]
What was different about your job working on lunar prospector?
Now Lunar Prospector was a spacecraft that actually had some similarities
and differences. The similarities involved coordination of tests needed
to validate the spacecraft. The main difference is we were testing hardware
that was not coming back for servicing. For this reason we had to be very
careful. We also had to really understand any problems before we could
continue to test. This was a new experience for me because it was a project
that dealt with space, which has no atmosphere to work against. Things
like lift and drag were not involved in the design and construction of
the vehicle. Instead we had to worry about lack of gravity and solar winds
and spacecraft power from the sun. Lunar Prospector was a lot of fun!
[ Ross/Ames - 26
- 09:48:35 ]
RE: [Christin/homeschool-Christin/homeschool] What exactly
do you look for when you test jets in the wind tunnel?
There are a number of things depending on the objective of the test. For
the most part we look at things like lift and drag characteristics because
these are the most important parts of airplane design. For fighters, a
lot of lift and a little drag is best. A lot of lift means we can get
to the fight faster, a little drag means we can go farther on the same
amount of fuel. We also look at performance characteristics: how will
the airplane fly when we have the flaps drooped, or how will it fly when
there are a lot of bombs underneath the fuselage, how will it fly if we
make a hard left turn.
[ Ross/Ames - 28
- 09:51:51 ]
RE: [Patti/CJHS] Did you get to go watch the
Lunar Prospector launch?
I was fortunate to not only watch the launch at Kennedy Space Center in
Florida, but I even participated in launch preparations. I was able to
sit in the Launch Control Room where they did the countdown. My family
saw me on TV and my oldest son was really excited about it. It was an
experience of a lifetime. If you ever get a chance to see a Shuttle launch
or other rocket launch I would highly recommend it.
[ Ross/Ames - 31
- 09:54:55 ]
RE: [Parker/HomesteadHigh] What colors are the pressure sensitive
Actually the pressure sensitive paint is white when applied in normal
light. The system we use at Ames turns pink when we shine the ultraviolet
lights. McDonnell Douglas had their own pressure sensitive paint that
turned yellow when they shined their special lights on the paint. Now
the pictures we received after the data was analyzed by the computers
showed the colors of a rainbow: blue, green, red, yellow, purple, orange.
Each color represented a pressure level on the surface.
- 32 - 09:57:14 ]
Wow, some great questions today! Thanks kids! Send in your last ones the
chat will end at 10 am.
[ Ross/Ames - 33
- 09:58:58 ]
RE: [Christin/homeschool] How can you see the affects of
the lift and drag on the planes in the wind tunnel? Is it all measured
Actually you cannot physically see the effects of lift and drag in the
wind tunnel. There is instrumentation on the airplane that measures the
pressure as well as a balance in the model that can measure the forces
placed in it when the air is blown across the plane. A computer then takes
the data and computes the lift and drag. We also have a computer program
that takes the data and creates plots. It is these plots that aerodynamics
engineers use to assess the performance of the plane. The pressure data
is used to compare the results of the force balance. Aerodynamicists use
special equations to calculate lift and drag from the pressure readings.
[ Ross/Ames - 35
- 10:04:52 ]
RE: [Patti/CJHS] Do most planes begin as military and then
get commercial application? or do commercial companies come to you for
testing? and how does that work in a government facility?
They don't generally begin as military applications. Military and commercial
airplanes have very different design requirements. On the other hand the
fundamentals of the design are the same. An aeronautical engineer will
use the same tools to design a military airplane as a commercial airplane.
Military airplanes typically want to go faster and higher and carry fewer
people. Both types of airplanes have wind tunnel testing as a verification
test in the design process. Being a government facility we have the advantage
of supporting to both military and commercial companies. Whoever wants
to run a wind tunnel test need only have the money. Also, one of NASA's
missions is to support the advancements of aircraft technologies.
[ Ross/Ames - 38
- 10:08:24 ]
Thank you very much Ross, I learned a lot! Your answers were wonderful,
bye kids see you next time!
Thanx for the opportunity to talk to you all.