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Quantitative determination of engine water ingestionA nonintrusive optical technique is described for determination of liquid mass flux in a droplet laden airstream. The techniques were developed for quantitative determination of engine water ingestion resulting from heavy rain or wheel spray. Independent measurements of the liquid water content (LWC) of the droplet laden airstream and of the droplet velocities were made at the stimulated nacelle inlet plane for the liquid mass flux determination. The LWC was measured by illuminating and photographing the droplets contained within a thin slice of the flow field by means of a sheet of light from a pulsed laser. A fluorescent dye introduced in the water enchanced the droplet image definition. The droplet velocities were determined from double exposed photographs of the moving droplet field. The technique was initially applied to a steady spray generated in a wind tunnel. It was found that although the spray was initially steady, the aerodynamic breakup process was inherently unsteady. This resulted in a wide variation of the instantaneous LWC of the droplet laden airstream. The standard deviation of ten separate LWC measurements was 31% of the average. However, the liquid mass flux calculated from the average LWC and droplet velocities came within 10% of the known water ingestion rate.
Document ID
19870008269
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Parikh, P.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Hernan, M.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Sarohia, V.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
September 5, 2013
Publication Date
December 1, 1986
Subject Category
Aircraft Propulsion And Power
Report/Patent Number
JPL-PUB-D-3041
NASA-CR-180188
DOT/FAA/CT-86/10
NAS 1.26:180188
Accession Number
87N17702
Funding Number(s)
CONTRACT_GRANT: NAS7-918
CONTRACT_GRANT: DTFA03-81-A-00765
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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