Nasa Technical Reports
Optical Measurements of Axial and Tangential Steady-State Blade Deflections Obtained
Simultaneously
Author(s): Kurkov, Anatole P.; Dhadwal, Harbans S.
Abstract: Case-mounted fiber-optic sensors have been used by aircraft engine manufacturers
mainly to monitor blade vibration in fans and compressors. The simplest probe arrangement
is a spot probe where, typically, a center fiber ...
NASA Center: Glenn Research Center
Publication Year: 2000
Added to NTRS: 2007-02-01
Document ID: 20050192422
Dual-Laser Probe for Measuring Blade-Tip Clearance Tested
Author(s):Dhadwal, Harbans S.; Kurkov, Anatole P.
Abstract: A dual-probe, integrated fiber-optic laser system for measuring blade tip clearance
in rotating turbomachinery was developed cooperatively with Integrated Fiber Optic
Systems, Inc., and tested at the NASA Lewis Research ...
NASA Center: Glenn Research Center
Publication Year: 1999
Added to NTRS: 2006-11-08
Document ID: 20050188529
System Developed for Real-Time Blade-Flutter Monitoring in the Wind Tunnel
Author(s): Kurkov, Anatole P.; Dhadwal, Harbans S.; Radzikowski, mark; Strukov, Dmitri
Abstract: A real-time system has been developed to monitor flutter vibrations in turbomachinery.
The system is designed for continuous processing of blade tip timing data at a rate
of 10 MB sec. A USB 2.0 interface provides ...
NASA Center: Glenn Research Center
Publication Year: 2005
Added to NTRS: 2006-10-20
Document ID: 20050217299
Flocculation and aggregation in a microgravity environment (FAME)
Author(s): Ansari, Rafat R.; Dhadwal, Harbans S.; Suh, Kwang I.
Abstract: An experiment to study flocculation phenomena in the constrained microgravity environment
of a space shuttle or space station is described. The small size and light weight
experiment easily fits in a Spacelab Glovebox. Using ...
NASA Center: Glenn Research Center
Publication Year: 1994
Added to NTRS: 2006-08-03
Accession Number: 95N14572; Document ID: 19950008158
Dynamic Light Scattering With Improved Fiber-Optic Probes
Author(s):Dhadwal, Harbans Singh; Ansari, Rafat R.; Meyer, William V.
Abstract: Improved fiber-optic probes developed for use in dynamic light-scattering measurements.
Intended for measuring dynamic backscattering of laser light from concentrated suspensions
of particles in liquids, for purpose of ...
NASA Center: Glenn Research Center
Publication Year: 1995
Added to NTRS: 2005-09-30
Accession Number: 95B10427; Document ID: 19950065586; Report Number: LEW-15461
Multiple-Fiber-Optic Probe For Light-Scattering Measurements
Author(s):Dhadwal, Harbans Singh; Ansari, Rafat R.
Abstract: Multiple-fiber-optical probe developed for use in measuring light scattered at various
angles from specimens of materials. Designed for both static and dynamic light-scattering
measurements of colloidal dispersions. Probe ...
NASA Center: Glenn Research Center
Publication Year: 1996
Added to NTRS: 2005-09-30
Accession Number: 96B10088; Document ID: 19960017878; Report Number: LEW-15460
Simultaneous Optical Measurements of Axial and Tangential Steady-State Blade Deflections
Author(s): Kurkov, Anatole P.; Dhadwal, Harbans S.
Abstract: Currently, the majority of fiber-optic blade instrumentation is being designed and
manufactured by aircraft-engine companies for their own use. The most commonly employed
probe for optical blade deflection measurements is ...
NASA Center: Glenn Research Center
Publication Year: 1999
Added to NTRS: 2005-08-25
Document ID: 19990032035; Report Number: E-11587, NAS 1.15209051, NASA TM-1999-209051
Time-of-Flight Tip-Clearance Measurements
Author(s):Dhadwal, H. S.; Kurkov, A. P.; Janetzke, D. C.
Abstract: In this paper a time-of-flight probe system incorporating the two integrated fiber
optic probes which are tilted equally relative to the probe holder centerline, is
applied for the first time to measure the tip clearance of ...
NASA Center: Glenn Research Center
Publication Year: 1999
Added to NTRS: 2005-08-25
Document ID: 19990047712; Report Number: AIAA Paper 99-2134, E-11692, NAS 1.15209183,
NASA TM-1999-209183
Fiber optic probes for laser light scattering Ground based evaluation for micgrogravity
flight experimentation. Integrated coherent imaging fiber optic systems for laser
light scattering and other applications
Author(s):Dhadwal, Harbans Singh
Abstract: The research work presented in this report has established a new class of backscatter
fiber optics probes for remote dynamic light scattering capability over a range of
scattering angles from 94 degrees to 175 degrees. The ...
NASA Center: NASA (non Center Specific)
Publication Year: 1994
Added to NTRS: 2005-08-25
Accession Number: 94N34914; Document ID: 19940030408; Report Number: NAS 1.26194377,
NASA-CR-194377
Integrated fiber optic probe for dynamic light scattering
Author(s):Dhadwal, Harbans S.; Khan, Romel R.; Suh, Kwang
Abstract: An integrated fiber optic probe, comprising a monomode optical fiber fusion spliced
to a short length of a graded-index multimode fiber, is fabricated for use as a coherent
receiver in dynamic light scattering. The multimode ...
NASA Center: Glenn Research Center
Publication Year: 1993
Added to NTRS: 2004-11-03
Accession Number: 93A52415; Document ID: 19930068418
Microemulsion characterization by the use of a noninvasive backscatter fiber optic
probe
Author(s): Ansari, Rafat R.; Dhadwal, Harbans S.; Cheung, H. M.; Meyer, William V.
Abstract: This paper demonstrates the utility of a noninvasive backscatter fiber optic probe
for dynamic light-scattering characterization of a microemulsion comprising sodium
dodecyl sulfate 1-butanol brine heptane. The fiber probe, ...
NASA Center: Glenn Research Center
Publication Year: 1993
Added to NTRS: 2004-11-03
Accession Number: 93A52412; Document ID: 19930068415
A fiber optic probe for the detection of cataracts
Author(s): Ansari, Rafat R.; Dhadwal, Harbans S.
Abstract: A compact fiber optic probe developed for on-orbit science experiments was used to
detect the onset of cataracts, a capability that could eliminate physicians' guesswork
and result in new drugs to 'dissolve' or slow down the ...
NASA Center: Glenn Research Center
Publication Year: 1993
Added to NTRS: 2004-11-03
Accession Number: 93N25593; Document ID: 19930016404
Fiber optic detector probes for laser light scattering
Author(s):Dhadwal, Harbans S.; Wu, Chi; Chu, Benjamin
Abstract: An experimental investigation of the role of fiber optic detector probes in laser
light scattering is presented. A quantitative comparison between different detector
configurations is accomplished by measuring the time taken ...
NASA Center: NASA (non Center Specific)
Publication Year: 1989
Added to NTRS: 2004-11-03
Accession Number: 90A11593; Document ID: 19900024538
Development of a fiber optic compressor blade sensor
Author(s):Dhadwal, Harbans Singh
Abstract: A complete working prototype of the fiber optic blade tip sensor was first tested
in the laboratory, followed by a thorough evaluation at NASA W8 Single Compressor
Stage Facility in Lewis Research Center. Subsequently, a ...
NASA Center: NASA (non Center Specific)
Publication Year: 1995
Added to NTRS: 2004-11-03
Accession Number: 96N15993; Document ID: 19960008827; Report Number: NAS 1.26199298,
NASA-CR-199298
Afiber-optic probe for particle sizing in concentrated suspensions
Author(s):Dhadwal, Harbans S.; Ansari, Rafat R.; Meyer, William V.
Abstract: A fiber-optic probe employing two monomode optical fibers, one for transmitting a
Gaussian laser beam to the scattering volume and the second, positioned at some backscatter
angle, for receiving the scattered light is ...
NASA Center: Glenn Research Center
Publication Year: 1991
Added to NTRS: 2004-11-03
Accession Number: 92A21371; Document ID: 19920038747
Coherent fiber optic sensor for early detection of cataractogenesis in a human eye
lens
Author(s):Dhadwal, Harbans S.; Ansari, Rafat R.; Dellavecchia, Michael A.
Abstract: A lensless backscatter fiber optic probe is used to measure the size distribution
of protein molecules inside an excised, but intact, human eye lens. The fiber optic
probe, about 5 mm in diameter, can be positioned ...
NASA Center: Glenn Research Center
Publication Year: 1993
Added to NTRS: 2004-11-03
Accession Number: 93A37051; Document ID: 19930053054
A fiber optic sensor for ophthalmic refractive diagnostics
Author(s): Ansari, Rafat R.; Dhadwal, Harbans S.; Campbell, Melanie C. W.; Dellavecchia, Michael A.
Abstract: This paper demonstrates the application of a lensless fiber optic spectrometer (sensor)
to study the onset of cataracts. This new miniaturized and rugged fiber optic probe
is based upon dynamic light scattering (DLS) ...
NASA Center: Glenn Research Center
Publication Year: 1992
Added to NTRS: 2004-11-03
Accession Number: 92A34831; Document ID: 19920052207
Multiple fiberoptic probe for several sensing applications
Author(s):Dhadwal, Harbans S.; Ansari, Rafat R.
Abstract: A multiple fiber-optic particle sizing probe which uses a linear array of 11 optical
fibers positioned in the focal plane of a graded index microlens is presented. The
probe, a compact optical spectrum analyzer, provides ...
NASA Center: Glenn Research Center
Publication Year: 1991
Added to NTRS: 2004-11-03
Accession Number: 93A53109; Document ID: 19930069112
Design of fiber optic probes for laser light scattering
Author(s):Dhadwal, Harbans S.; Chu, Benjamin
Abstract: A quantitative analysis is presented of the role of optical fibers in laser light
scattering. Design of a general fiber optic microlens probe by means of ray tracing
is described. Several different geometries employing an ...
NASA Center: NASA (non Center Specific)
Publication Year: 1989
Added to NTRS: 2004-11-03
Accession Number: 90N17090; Document ID: 19900007774