|
   |
 |
                 
|
UPDATE #36 - October 9, 1998 PART 1: NASA K-12 Online Aeronautics project INTRODUCTION TO NASA K-12 ONLINE AERONAUTICS PROJECTS: WEB CAST &
CHAT
Wednesday, October 14, 1998
1:00 pm - 2:30 pm Pacific (4:00 pm - 5:30 pm Eastern)
During this event we will introduce you to four exciting online
projects. If you are unable to join us for the
entire event we have provided approximate times that will allow
you to attend the portion of the program that
is the most relevant to you:
1:00 pm - 1:05 pm Pacific (4:00 pm - 4:05 pm Eastern)
Introduction
1:05 pm - 1:25 pm Pacific (4:05 pm - 4:25 pm Eastern)
Grades K-2
Off to a Flying Start
http://k12unix.larc.nasa.gov/flyingstart
1:25 pm - 1:45 pm Pacific (4:25 pm - 4:45 pm Eastern)
Grades 5-8
Aerospace Team Online
http://quest.arc.nasa.gov/aero
1:45 pm - 2:05 pm Pacific (4:45 pm - 5:05 pm Eastern)
Grades 9 - 12
FoilSim: Basic Aerodynamics Software
http://www.lerc.nasa.gov/WWW/K-12/aerosim
2:05 pm - 2:25 pm Pacific (5:05 pm - 5:25 pm Eastern)
Grades K-14
Cooperative Agreement Aeronautics Projects
http://learn.ivv.nasa.gov/education/topics/aeronautics.html
2:25 pm - 2:30 pm Pacific (5:25 pm - 5:30 pm Eastern)
Wrap-up and web chat
Technologies Available During the Live Events:
(Caution: These links may not be active until the time of the
event.)
RealMedia
RealAudio
For more information go to
http://quest.arc.nasa.gov/ltc/lewis/tgir/index.html
UPCOMING CHATS
Wednesday, October 14, 1998, 1:00 p.m. Pacific Time: Fanny Zuniga, aerospace engineer Fanny spends most of her time conducting experiments and studying data to help build better airplanes and space vehicles. She is currently working with a group on the High-Speed Research project. Their goal is to build a new airplane capable of carrying up to 300 passengers and flying at about twice the speed of today's commercial transports. Fanny will answer questions in english and spanish. Read Fanny's autobiography at http://quest.arc.nasa.gov/aero/team/zuniga.html Register for this chat at http://quest.arc.nasa.gov/aero/chats/#chatting Friday, October 16, 1998, 10 AM Pacific Time: Stephen Jaeger, aeroacoustics engineer Aeroacoustics is the study of aircraft noise. Stephen's responsibilities in this area include developing tools for measuring aircraft noise, and conducting acoustics research on wind tunnel models of supersonic jets, airliners and aircraft engines. Read Stephen's autobiography at http://quest.arc.nasa.gov/aero/team/jaeger.html Register for this chat at http://quest.arc.nasa.gov/aero/chats/#chatting PROJECT NEWS
Collaborative Events To Begin! Several new aeronautics projects will have students working collaboratively online. One activity is targeted for elementary and middle school classes. Two others will be for high school or junior high school kids. These higher end activities might not be done as an entire class; other users may include science clubs, GATE kids or science fair folk. The ELEMENTARY / MIDDLE SCHOOL - Right Flying on-line collaborative activity is now online. http://quest.arc.nasa.gov/aero/events/collaborative/elem-mid.html The HIGH SCHOOL / JUNIOR HIGH SCHOOL - Free Flight Analysis: an "in-flight" movie" and HIGH SCHOOL / JUNIOR HIGH SCHOOL - Wind tunnel building activities will be online next week. For more information go to http://quest.arc.nasa.gov/aero/events/collaborative/index.html All of us at Quest hope you will consider joining us for this online festival of learning. Wright Flyer Coloring Contest Which category will you choose for your entry "Most Realistic" or "Most Patriotic"? Check out all the categories and join the fun. Hey those of you who are good a graphics programs, let's see what you come up with!! To find the details go to http://quest.arc.nasa.gov/aero/wright/events/contest/coloring.html [Editor's Note: Stephen Jaeger is an aeroacoustic engineer. He's the guy who's helping engineers design quiet airplanes. Read his bio at: http://quest.arc.nasa.gov/aero/team/jaeger.html This journal with pictures can be found at http://quest.arc.nasa.gov/aero/team/fjournals/jaeger/6db.html SIX DECIBELS PER DOUBLING by Stephen Jaeger September 10, 1998 It was a crazy summer. I was very busy at work, I took a class at Stanford and I got married...all in one summer! Two months ago we finished up our wind-off calibration of the new 40- by 80-Foot Wind Tunnel test section. (Wind-off means we didn't turn the wind tunnel on. We will do the wind-on calibration later this month.) For the wind-off calibration, we were interested in how much of an echo we were going to get from the walls of the wind tunnel. During the first month we fired off pistols and cannons and other noise sources to measure the reflections as I discussed before. The remaining part of the test was an assessment of the decay properties of the test section. Imagine you are out in the middle of a field somewhere. In front of you is a loudspeaker with your favorite music playing. As you move away from the speaker the music will get quieter and quieter until you can't hear it at all. In fact, you may notice that the loudness of the music will decay rapidly as you first start to move away. However, when you are further away, you will have to walk a much greater distance to notice anymore change. Try it sometime. This phenomenon is well known in science and applies to other "point sources" such as light and radio waves. Sometimes acousticians call it the "6 dB per doubling law." It says that the sound pressure will decrease by 6 decibels each time you double your distance from the speaker. So if the speaker is screaming at 100 dB at 10 feet away, it will still be at 94 decibels from 20 feet away. (A decibel (dB) is a measure of sound pressure. A whisper is about 50 dB, someone talking is about 70 dB, a jet plane might be 100 dB, and a rock band might get to 120 dB near the stage.) The above is not true in a room, however. Because of all the reflections from the walls the noise can still be loud even from far away. This is why a basketball game is so much louder inside an auditorium than it is on an outside court. For our wind tunnel, we want the noise environment to be the way it would on the outside. One way to test this is to place a noise source at one end of the tunnel and position a microphone at different distances from the source and determine if the sound does indeed follow the "6 dB per doubling law." Of course it won't because we're in a big room, but we can get close to it if we designed the room correctly. We used three noise sources to test the decay: 1) An 18-inch woofer in a speaker cabinet. The woofer provides low frequency noise. 2) The dodecahedron. The dodecahedron is a 12-sided ball with twelve 8-inch speakers mounted in each face. The dodecahedron is supposed to radiate mid-range frequency sound evenly in all directions. 3) The "Screaming Ted." The Screaming Ted Nugent, or Screaming Ted (named after a loud heavy metal guitarist from another era), produces ultrasonic white noise. It sounds like a high pitched hiss. Most of the sound generated by the Screaming Ted can't even be heard by humans, but dogs can probably hear most of it! With each of these noise sources we measured the decay of the noise with distance at different frequencies. We are still analyzing the data but it seems that we have a pretty good anechoic wind tunnel. This is a good thing because it cost you $25 million. SUBSCRIBING AND UNSUBSCRIBING
If this is your first message from the updates-aero list, welcome! To catch up on back issues, please visit the following Internet URL: http://quest.arc.nasa.gov/aero/updates To subscribe to the updates-aero mailing list (where this message came from), send a message to: listmanager@quest.arc.nasa.gov In the message body, write only these words: subscribe updates-aero CONVERSELY... To remove your name from the updates-aero mailing list, send a message to: listmanager@quest.arc.nasa.gov In the message body, write only these words: unsubscribe updates-aero |
||
|
|
|
