NASA Scientific and Technical Aerospace Reports

measured using a heterodyne laser in an eight-pass interferometer configuration. The final stage system will be housed in a
vacuum environment and operated in a temperature-controlled laboratory. Results from a simple single coarse/fine axis system
will be the design basis for the final multi-axis system. It is expected that initial stage performance evaluation will be presented
at the conference.
NTIS
Evaluation; Nanotechnology; Performance Tests
20060002488 Lawrence Livermore National Lab., Livermore, CA USA
Design of an Illumination Technique to Improve the Identification of Surface Flaws on Optics
Prasad, R. R.; Bernacil, M.; Halpin, J.; Peterson, J.; Mills, S.; Nov. 11, 2004; 12 pp.; In English
Report No.(s): DE2005-15014579; No Copyright; Avail.: National Technical Information Service (NTIS)
An edge illumination technique has been designed using a monochromatic light source that improves the identification
of surface flaws on optics. The system uses a high-resolution CCD camera to capture images of the optics. Conventional edge
illumination methods using white light sources have been plagued by light leaking around the optics causing high background
levels. The background combined with lower resolution cameras has made it difficult to determine size and intensity
characteristics of the flaws. Thus photographs taken of the optics are difficult to analyze quantitatively and do not allow for
the detection of small, faintly illuminated sites. Infrared diodes have been utilized to illuminate large-scale (43 cm x 43 cm)
fused silica optics, and a two-dimensional array CCD camera has been used to collect the image data.
NTIS
Surface Defects; Illumination; Optics
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FLUID MECHANICS AND THERMODYNAMICS
Includes fluid dynamics and kinematics and all forms of heat transfer; boundary layer flow; hydrodynamics; hydraulics; fluidics; mass
transfer and ablation cooling. For related information see also 02 Aerodynamics.
20060001733 General Motors Research Labs., Warren, MI, USA
Real-Time Analysis of Fuel Spray Images
Badreldin, Amira M.; IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP ‘87); Volume 1;
1987, pp. 14.19.1 - 14.19.3; In English; See also 20060001583; Copyright; Avail.: Other Sources
This paper provides a fast and efficient technique for real-time preprocessing and analysis of fuel spray images. The
preprocessing stage consists of global thresholding of the log-edge of the image. The recognition of in-focus droplets is
achieved through a 3-1evel tree classifier. The algorithm was tested using 400 images including approximately 8000 candidate
objects. The percentage of correct classification was \g 93%. The algorithm was also tested using 200 images of very low
quality, and a recognition rate of 87% was achieved.
Author
Real Time Operation; Fuel Sprays; Preprocessing
20060001798 Air Force Inst. of Tech., Wright-Patterson AFB, OH USA
Characterization of the Global Hawk Low Pressure Turbine First Rotor
Garmoe, Timothy L.; Sep. 1, 2005; 137 pp.; In English; Original contains color illustrations
Report No.(s): AD-A440261; AFIT/GAE/ENY/05-S02; No Copyright; Avail.: Defense Technical Information Center (DTIC)
The Air Force Research Laboratory, Propulsion Directorate at Wright Patterson Air Force Base has studied the
performance of turbine blade geometries utilizing a large scale, low speed, drawdown wind tunnel in an effort to better
understand gas turbine blade aerodynamics. Currently, the Air Force’s Unmanned Aerial Vehicle (UAV) Global Hawk has been
operated primarily at flight conditions other than the design point of its Allison AE3007H turbofan engine. This off design
condition decreased the Reynolds number at the low pressure turbine causing losses in efficiency and loading. Two different
blades were studied to maximize performance of the Global Hawk turbine. The first was an experimental, high turning angle
blade designated the Pak-B and the second was based on the two dimensional mean diameter section of the first stage blade
of the low pressure turbine used in the Global Hawk (GH1R). The Pak-B blade has been the subject of past research. The
primary goals of this study were to validate the wind tunnel after previous upgrades, physically modify the test section to
accept the Global Hawk blades, and to characterize the GH1R blades. A Reynolds number sweep was performed from 10K
to 100K by 5K increments on a linear turbine cascade of 8 first rotor test blades. Measurements of wake velocity, total pressure
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