NASA Scientific and Technical Aerospace Reports

20040073472 Taitech, Inc., Beavercreek, OH, USA
Computation of Low Speed Cavity Noise
Blech, Richard A., Technical Monitor; Loh, Ching Y.; April 2004; 17 pp.; In English; 42nd Aerospace Sciences Meeting and
Exhibit, 5-8 Jan. 2004, Reno, NV, USA
Contract(s)/Grant(s): NAS3-03072; WBS 22-708-90-25
Report No.(s): NASA/CR-2004-212892; AIAA Paper 2004-0680; E-14310; No Copyright; Avail: CASI; A03, Hardcopy
Over the last five years, the Aircraft Icing Project of the NASA Aviation Safety Program has developed a number of
in-flight icing education and training aids to support increased awareness for pilots of the hazards associated with atmospheric
icing conditions. Through the development of this work, a number of new instructional design approaches and media delivery
methods have been introduced to enhance the learning experience, expand user interactivity and participation, and, hopefully,
increase the learner retention rates. The goal of using these multimedia techniques is to increase the effectiveness of the
training materials. This paper will describe the multimedia technology that has been introduced and give examples of how it
was used.
Author
Aircraft Icing; Cavities; Low Speed; Multimedia; Numerical Analysis; Aeroacoustics
20040073596 Space and Naval Warfare Systems Center, San Diego, CA
Distributed Surveillance Sensor Network
Nov. 1997; 7 pp.; In English; Original contains color illustrations
Report No.(s): AD-A422440; No Copyright; Avail: CASI; A02, Hardcopy
Develop capabilities for multiple undersea vehicles to support and interact with assorted undersea surveillance sensors in
a manner which enhances the overall capabilities of the Fleet in the area of undersea 15k. Integrate the technologies developed
by the AOSN (Autonomous Ocean Sampling Network), the ULITE underwater acoustic sensor array and the Flying Plug
underwater connectivity device into a coherent demonstration of new technological capabilities in which the whole is greater
than the sum of the various parts (Figure 1).
DTIC
Acoustics; Signal Detectors; Surveillance
20040073675 Washington Univ., Seattle, WA
Experimental Study of Sound Waves in Sandy Sediment
Yargus, Michael W.; May 2003; 117 pp.; In English; Original contains color illustrations
Contract(s)/Grant(s): N00014-98-1-0040
Report No.(s): AD-A422568; APL-UW-TR-0301; No Copyright; Avail: CASI; A06, Hardcopy
This dissertation describes experiments intended to help understand the physics of sound (compressional waves)
propagating through sandy sediments (unconsolidated porous media). The theory (using a lumped parameter model) and
measurements (using a reflection ratio technique) includes derivations and measurements of acoustic impedance, effective
densities, wave speeds (phase velocities), effective pressures, mode shapes, pressure reflection coefficients, and material
moduli. The results show the acoustic impedance divided by the phase velocity, rendering an "effective density,"
is less than the total density of the sediment (effective density 89% plus or minus 3% of total). The results also show the fluid
in the sediment oscillates back-and-forth 2.2 plus or minus 0.4 times farther than the sand in the sediment (mode shape) during
the passing of a sound wave. These facts suggest the existence of Biot waves (two compressional waves) in water- saturated
sand.
DTIC
Sands; Sediments; Sound Waves
20040073698 Washington Univ., Seattle, WA
ASIAEX, East China Sea, Cruise Report of the Activities of the R/V melville, 29 May to 9 June 2001
Dahl, Peter H.; Jul. 2001; 34 pp.; In English; Original contains color illustrations
Contract(s)/Grant(s): N00014-96-1-0325
Report No.(s): AD-A422598; APL-UW-TM-7-01; No Copyright; Avail: CASI; A03, Hardcopy
Science teams from APL-UW, MPL-SIO, and URI deployed a constellation of instruments from the R/V Melville to
measure acoustic propagation and scattering over a broad frequency range (100 Hz to 20 kHz), and environmental acoustic
variables in the East China Sea (ECS). This work was completed from 29 May 2001 to 9 June 2001 as part of the Asian Seas
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