NASA Scientific and Technical Aerospace Reports

20040068248 Lawrence Livermore National Lab., Livermore, CA
Acoustically-Driven Microfluidic Systems
Wang, A. W.; Benett, E. J.; Tarte, L. R.; Jun. 23, 2000; 10 pp.; In English
Report No.(s): DE2004-15006374; UCRL-JC-138305; No Copyright; Avail: Department of Energy Information Bridge
We have demonstrated a non-contact method of concentrating and mixing particles in a plastic microfluidic chamber
employing acoustic radiation pressure. A flaw cell package has also been designed that integrates liquid sample interconnects,
electrical contacts and a removable sample chamber. Experiments were performed on 1, 3, 6, and 10(micro)m polystyrene
beads. Increased antibody binding to a solid-phase substrate was observed in the presence of acoustic mixing due to improve
mass transport.
NTIS
Acoustic Emission; Sound Waves; Mass Transfer
20040068252 Lockheed Martin Corp., Syracuse, NY, USA
Methods of Measuring Lock-In Strength and their Application to the Case of Flow over a Cavity Locking into a Single
Side Branch Resonator
Mendelson, R. S.; Apr. 2003; In English
Report No.(s): DE2004-821511; LM-03K030; No Copyright; Avail: National Technical Information Service (NTIS)
Lock-in is a non-linear interaction between a flow induced noise source and a resonator when their respective frequencies
are near each other. Lock-in has been reported under many different labels and for many different applications. There is a need
however for a consistent community wide method to measure the strength of lock-in so that data from different tests and
different source/resonator combinations can be compared. This paper discusses three methods for measuring lock-in strength.
The first, Resonant Response Method, (RRM) subtracts (in the decibel scale) the linear modal response of the resonator to
broadband (BB) flow noise from the resonant response when lock-in occurs. The second, Quality Factor Method (QFM) tracks
the change in quality factor of the resonant response. The third defines the strength in terms of the difference between peak
response and the local BB levels.
NTIS
Acoustics; Resonators
20040068370 Sverdrup Technology, Inc., Huntsville, AL, USA, NASA Marshall Space Flight Center, Huntsville, AL, USA
Measuring Thermal Conductivity at LH2 Temperatures
Selvidge, Shawn; Watwood, Michael C.; [2004]; 1 pp.; In English; 45th AIAA/ASME/ASCE/AHS/ASC Structures,
Structural Dynamics and Materials Conference, 19-22 Apr. 2004, Palm Springs, CA, USA
Contract(s)/Grant(s): NAS8-00187; No Copyright; Avail: Other Sources; Abstract Only
For many years, the National Institute of Standards and Technology (NIST) produced reference materials for materials
testing. One such reference material was intended for use with a guarded hot plate apparatus designed to meet the requirements
of ASTM C177-97, "Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission
Properties by Means of the Guarded-Hot-Plate Apparatus." This apparatus can be used to test materials in various
gaseous environments from atmospheric pressure to a vacuum. It allows the thermal transmission properties of insulating
materials to be measured from just above ambient temperature down to temperatures below liquid hydrogen. However, NIST
did not generate data below 77 K temperature for the reference material in question. This paper describes a test method used
at NASA’s Marshall Space Flight Center (MSFC) to optimize thermal conductivity measurements during the development of
thermal protection systems. The test method extends the usability range of this reference material by generating data at
temperatures lower than 77 K. Information provided by this test is discussed, as are the capabilities of the MSFC Hydrogen
Test Facility, where advanced methods for materials testing are routinely developed and optimized in support of aerospace
applications.
Author
Liquid Hydrogen; Thermal Conductivity; Temperature Distribution; Aerospace Engineering
20040070710 NASA Ames Research Center, Moffett Field, CA, USA
Adaptive Low Dissipative High Order Filter Methods for Multiscale MHD Flows
Yee, H. C.; Sjoegreen, Bjoern; January 13, 2004; 1 pp.; In English; No Copyright; Avail: Other Sources; Abstract Only
Adaptive low-dissipative high order filter finite difference methods for long time wave propagation of shock/turbulence/
combustion compressible viscous MHD flows has been constructed. Several variants of the filter approach that cater to
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