November 9, 1998
QuestChat with Gloria Yamauchi
NASA Ames Research Center, Moffett Field, CA
- 5 - 10:38:04 ]
Hello to our early arriving Aerospace Team Online chat participants! Today's
Aerospace Team Online chat with Gloria Yamauchi from NASA Ames Rsearch
Center will begin at 11:00 a.m., Pacific Standard Time. Be sure you have
read Gloria's autobiography at http://quest.arc.nasa.gov/aero/team/yamauchi.html
before joining this chat.
- 6 - 10:39:53 ]
Once the chat begins, Gloria will attempt to answer as many of your questions
as she can, but please be patient. The chat may be "moderated" if Gloria
falls behind with our questions. This means that only a few questions
will be posted to the chat room at a time. Don't worry if your questions
do not appear on your screen immediately. They will be posted as Gloria
answers those ahead of you.
- 7 - 10:40:37 ]
As a reminder, remember to enter "Your Handle" in the box provided, before
posting questions to the chat room. Once you've done this, please let
us know that you have logged on for today's chat.
- 8 - 10:41:33 ]
At the conclusion of today's chat, we ask that you take a few minutes
to let us know what you thought about it. For your convenience, you may
use our online feedback forms at http://quest.arc.nasa.gov/qchats/qchat-surveys.
We look forward to hearing from you!
- 9 - 10:54:37 ]
Hello and welcome to today's Aerospace Team Online chat with Gloria Yamauchi
from NASA Ames Research Center! Gloria conducts research in rotor aerodynamics
and acoustics. The objectives of her work are to understand the flow environment
of rotor blades which, in turn, help her understand why rotors perform
the way they do and why they make so much noise. To study the rotor wake,
she sometimes runs large computer programs which simulate the air flow
around the blades. She also participates in wind tunnel and flight tests
where the rotor loads and noise are measured. By studying computational
results and experimental measurements, she tries to d etermine what is
happening in the flow field and whether the rotor noise can be reduced
and performance improved through design changes or operational changes.
- 10 - 10:54:56 ]
And now, here is Gloria Yamauchi to answer your questions.
- 14 - 10:59:16 ]
RE: [Dane] Why is it important to reduce
the amount of noise the rotors make?
The nice thing about helicopters is that they can be used for all sorts
of things. But if they are too noisy, the public will not accept them.
Helicopters are often used in cities and other crowded areas, so what
we want is a low-noise helicopter.
- 15 - 11:03:02 ]
RE: [Dane] You talked about working
on tilt rotors. How are tilt rotor craft used in the real world? What
are their advantages and disadvantages?
Tilt rotors can take off and land like a helicopter and also fly like
an airplane. Tilt rotors are currently being manufactured for the Navy;
their designation is the V-22 Osprey.Tilt rotors don't need runways since
they can land like a helicopter. We are hoping that tilt rotors will become
a common mode of commercial transportation in a few years. They will be
a perfect vehicle to transport people short distances (like from San Francisco
to Los Angeles).
- 19 - 11:07:39 ]
RE: [DebandDane] Hello! We are so glad
you agreed to chat with us. Unfortunately, we will not be able to be present
during the chat at the scheduled time, but we hope you will be able to
answer our questions. First, can you tell us why the rotors on a helicopeter
make so much noise?
The wop-wop sound you often hear when a helicopter flies overhead is mainly
caused by the rotor blades interacting or hitting part of its own wake.
A regular airplane wing will generate a wake (contrails) that trail straight
back from the wing. Because the rotor blade is rotating, the wake is like
a helix and the blades intersect the helix under certain operating conditions
(like when the helicopter is descending for a landing).
- 20 - 11:10:34 ]
RE: [Dane] What kind of materials are
used to construct the rotors? Have you ever seen one break?
These days rotor blades are made of composite materials. Fortunately,
I do not yet have first-hand experience in seeing a blade break. However,
we conduct a lot of wind tunnel tests here at Ames and once in a great
while, something will break. We accept this risk as part of research and
of course, we always learn a great deal from the failures.
- 21 - 11:13:55 ]
RE: [Deb] Is any of your research related
to helicopter safety?
I guess all the research we do ultimately has an impact on safety. Rotorcraft
are much more complex than airplanes and so we are always thinking of
how to conduct our research in a safe manner. This includes working closely
with our NASA helicopter pilots to get their feedback on the "real" life
operation of a helicopter.
- 23 - 11:17:03 ]
RE: [Dane] How are tilt rotor craft
different than fixed wing aircraft that can take off vertically?
Tilt rotors can fly helicopter-like conditions, that is, they can hover
and fly at low speeds. A VTOL (vertical take-off and landing) aircraft
such as a Harrier isn't really meant to fly low speeds. Also, tilt rotors
can carry many more passengers.
- 30 - 11:26:16 ]
RE: [Deb] I appreciated comments in
your autobiography about your wish you had had a mentor in high school.
Many students are overwhelmed and confused by the number of career choices
open to them. What sort of qualities do you think students should seek
in a mentor?
This is a good question. I would seek out a person who enjoys his/her
work and is patient and a good listener. A mentor doesn't have all the
answers, but a mentor should be able to give you ideas to follow up on.
A good mentor will also be willing to share his/her personal as well as
- 32 - 11:27:19 ]
RE: [Dane] What is the largest helicopter
that has ever been built?
Hmmm ... I'm not sure but I believe the Russians have built a VERY large
[ DaneandDeb - 26 - 11:17:21 ]
Thank you so much for your time and for sharing. We look forward to checking
out this chat in the archives.
- 28 - 11:21:58 ]
RE: [Yaitza] Hi. I wanted to know more
about the wake the rotors generate and what kind of calculations you use
to measure it.
The research community has made great strides in measuring rotor wakes.
In a recent experiment I was involved in, we first visualised the helix-like
wake by injecting smoke in the wind tunnel upstream of the rotor. We illuminate
the smoke using a powerful laser and then we record what we see on video.
From the video, we can later look at the images and figure out the geometry
of the wake. If we want to measure velocities in the wkae itself, one
technique we use is called Particle Image Velocimetry (PIV). Using PIV,
we can determine the velocity of the individual smoke particles in the
wake. There are other techniques as well.
- 34 - 11:33:32 ]
We'd like to remind you to use our online feedback forms at the conclusion
of today's chat. Please share your thoughts with us at http://quest.arc.nasa.gov/qchats/qchat-surveys.
- 35 - 11:33:41 ]
RE: [Yaitza] How do the rotors and the
force of the wind impact a pilot's ability to control the helicopter?
what aspects of the helicopter design counteract the effects and or balance
As with airplane pilots, I'm sure a helicopter pilot prefers calm and
steady air. There are several rules of thumb that a helicopter pilot must
keep in mind to avoid potentially dangerous rotor conditions and these
rules change somewhat depending on the configuration of the helicopter
(two-bladed, 3-bladed, no tail rotor (NOTAR), tail rotor). I wish I were
a pilot so I could give you some first-hand experiences!
[ Yaitza-Yaitza - 41 - 11:43:57 ]
That's alright- because of what you do know, I learned something about
PIVs, rotors, and wind tunnels!
- 39 - 11:42:26 ]
RE: [MrsMock] Hello Gloria. Martin wants
to know if you think tilt rotors will carry passengers from place to place?
Not replacing commercial jets.)
Tilt rotors can fill the short-haul (300 miles or so) commercial market.
In fact, Bell Helicopters is planning on producing a commercial tilt rotor
(I think it will carry 7-10 passengers). Airport congestion and building
more runways is very expensive, so tilt rotors are an attractive solution.
- 37 - 11:39:39 ]
RE: [MrsMock] Hello Oran, My computer
students are currently completing language and math exercises. They will
try to join the chat a little later. In the meantime, Amber would like
to know why Gloria decided to become an Aerospace engineer. Did she ever
take astronaut training?
Sometime during high school, I became interested in space (maybe I watched
too much Star Trek?) and NASA. I thought it would be neat to become an
astronaut. After I started working at Ames, I investigated the requirements
for becoming an astronaut. The requirements for a Mission Specialist included
an advanced degree (usually a PhD or MD) and a certain level of correctable
vision. I discovered that my eyesight was probably not good enough. As
the years went by, I sort of gave up the idea of being an astronaut. But
I think it would still be fun to be involved on the research side of a
- 45 - 11:48:58 ]
For those of you interested in learning about upcoming chats with Aerospace
Team Online experts, visit the ADTO chat schedule page at http://quest.arc.nasa.gov/aero/chats.
- 47 - 11:50:40 ]
How many classes did it take to get to your position?
Well, I got hired with just a BS degree in Mechanical Engineering. However,
I was encouraged to pursue a Master's degree and so I started taking classes
shortly after I started work at Ames. I spent about 2 years taking classes
for the MS (part-time). After the Masters, I did more experimental research
and discovered that there is so much more to learn about aerodynamics
and dynamics. So, I decided to take more classes and go for a PhD. I needed
6 years to finish the degree since I was still working full-time. For
a research position in Aeronautics, NASA hires graduates with a BS, MS,
or PhD in mechanical or aerospace engineering.
- 48 - 11:52:24 ]
Do you have any children?
I don't have any kids. Which is probably why my dog Hobbes is so spoiled!
I think it would be nice to have a family.
- 50 - 11:53:18 ]
Is it hot or cold in space?
It is very cold in space.
- 52 - 11:55:48 ]
RE: [Kimber] Did you ever meet Carl
Sagan when you went to Cornell U.?
When I was a freshman, I attended a lecture by Prof. Sagan. He was a very
good speaker and showed pictures of Jupiter and other planets (I think
NASA had just sent out a probe - Voyager maybe?). I don't think Prof.
Sagan taught a regular class while I was at CU.
- 53 - 11:57:53 ]
RE: [Lauren] What is your favorite thing
to do in your spare time?
I like to play golf (I'm not very good though), play basketball, go fishing,
and read. I like sci-fi books and books about King Arthur.
- 55 - 12:00:46 ]
As Gloria answers the final questions in today's chat, we'd like to thank
everyone for joining us today!
- 56 - 12:01:14 ]
Did you find any gold when you grew up?
Gold? Let's see, when I was little we used to go to Folsom Lake outside
of Sacramento and I thought I found a lot of gold. But then I found out
the glittering pieces I collected on the beach was just Fool's Gold.
- 57 - 12:01:17 ]
Be sure to let us know what you thought about today's chat at http://quest.arc.nasa.gov/qchats/qchat-surveys.
[ Yaitza-Yaitza - 58 - 12:01:59 ]
I have to go, thank you for your time!
- 59 - 12:02:12 ]
A very special thanks to Dr. Gloria Yamauchi from NASA Ames Research Center
for chatting with us today, and sharing her time and expertise with us.
- 60 - 12:02:52 ]
We invite you to join us for upcoming chats with NASA experts. Check our
schedule of events page at http://quest.arc.nasa.gov/common/events for more information
about these chats.
- 61 - 12:03:45 ]
Thank you Gloria for chatting with us. We learned a lot.
- 62 - 12:05:54 ]
Thank you again to everyone for joining us for today's chat!