Direct Optical Measurement of Vorticity in Fluid Flow

reportActive / Technical Report | Accession Number: AD1001828 | Open PDF

Abstract:

Even though vorticity is one of the most important variables in fluid dynamics, we do not currently have a practical way to measure it directly and in a non-intrusive fashion. In this exploratory research effort we demonstrate the first direct and localized non-intrusive measurement of vorticity in afluid flow using the Rotational Doppler Effect RDE and Laguerre-Gaussian LG light beams that possess orbital angular momentum OAM.The approach has been implemented in the flow field of solid body rotation where the flow vorticity is known precisely. Experimental results arefound to be in excellent agreement with the expected values.

Author(s):
Koochesfahani, Manoochehr ; Dantus, Marcos
Author Organization(s):
Michigan State University East Lansing United States
Descriptive Note:
Technical Report,15 Sep 2014,14 Sep 2015
Pagination:
0013

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release
Distribution Statement:
Approved For Public Release;

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
AFRL-AFOSR-VA-TR-2016-0029
Monitor Series:
AFRL-AFOSR-VA-TR-2016-0029
 Subject Terms
Joint Capability Areas:
JCA_2.2.1_Signals Collection; JCA_2.2_Collection; JCA_1.2.7_Experimentation; JCA_5_Command and Control; JCA_4.5.1_Contract Support Integration; JCA_4.5_Operational Contract Support; JCA_5.3_Planning; JCA_5.5.2_Task; JCA_5.5_Direct
Communities of Interest:
Advanced Electronics
Descriptor(s):
fluid flow, fluid dynamics, laser beams, angular momentum, flow fields, measurement, images, lasers
Keyword(s):
Fluid flow imaging, Optical diagnostics, Molecular Tagging Velocimetry, Femtosecond lasers, vorticity
Report Date:
2015 Dec 11
Creation Date:
2017 Apr 24