DEVELOPMENT OF A SCANNING PULSED DIODE LASER DOPPLER VELOCIMETER FOR FLOW MEASUREMENTS IN COASTAL AND MARINE ENVIRONMENTS

Award Information
Agency: Department of Defense
Branch: Navy
Contract: N/A
Agency Tracking Number: 8621
Amount: $250,000.00
Phase: Phase II
Program: SBIR
Awards Year: 1989
Solicitation Year: N/A
Solicitation Topic Code: N/A
Solicitation Number: N/A
Small Business Information
21414 - 68th Ave S, Kent, WA, 98032
DUNS: N/A
HUBZone Owned: N
Woman Owned: N
Socially and Economically Disadvantaged: N
Principal Investigator
 Peter H -t Liu
 (206) 872-8500
Business Contact
Phone: () -
Research Institution
N/A
Abstract
A SCANNING, PULSED DIODE LASER DOPPLER VELOCIMETER (DLDV/SP) WILL BE DEVELOPED FOR FLOW MEASUREMENTS IN AIR AND WATER, PARTICULARY COASTAL WATERS AND THE MARINE ATMOSPHERIC BOUNDARY LAYER. THE DLDV/SP, BASED ON A FIELD-PROVEN DLDV FOR OCEAN DEPLOYMENT UNDER ICE FLOWS, WILL BE DESIGNED FOR ON-AXIS BACKSCATTER OPERATION. IN A PULSED MODE, THE DIODE LASER WILL GENERATE INSTANTANEOUS LASER POWER IN THE TENS OF WATTS, WHICH IS NECESSARY FOR THE SCANNING, BACKSCATTER OPERATION. TWO CRITICAL ISSUES THAT MUST BE RESOLVED ARE THE EXTREMELY SHORT PULSE WIDTH (200 TO 500 NS) AND THE RELATIVELY LARGE SPECTRAL WIDTH (ABOUT 3.5 NM). TO RESOLVE THESE ISSUES, WE PROPOSE, RESPECTIVELY, THE INCORPORATION OF AN OPTICAL MODULATION SCHEME TO CREATE A "RUNNING" FRINGE PATTERN AND THE IMPLEMENTATION OF OPTICAL FILTERING OR AN ETALON. THE DLDV/SP WILL MEASURE PROFILES OF MEAN AND FLUCTUATING FLOW COMPONENTS AS WELL AS SHEAR FLOW. BECAUSE LASER ANEMOMETRY IS ALSO CAPABLE OF MEASURING PARTICLE SIZE DISTRIBUTION AND NUMBER DENSITY, SIMULTANEOUS MEASUREMENTS OF PARTICLE SPEED AND SIZE DISTRIBUTION AND NUMBER DENSITY MAY BE MADE WITH THE DLDV/SP. A ZOOM OPTICAL SYSTEM WILL BE DESIGNED FOR SCANNING THE FOCAL VOLUME, WITH RANGES ON THE ORDER OF 10 M IN AIR AND 1 M IN WATER. DURING PHASE I, A TEST MODEL WILL BE DESIGNED, ASSEMBLED, AND TESTED TO DETERMINE THE FEASIBILITY OF THE PROPOSED DEVELOPMENT.

* Information listed above is at the time of submission. *

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