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Implementation of the Lifetime Method in Unsteady Pressure Sensitive Paint MeasurementsAt NASA Ames Research Center, unsteady pressure-sensitive paint (uPSP) measurements are obtained using the ‘intensity method’ which measures paint luminescence in response to a continuous, constant excitation. These measurements are obtained using high-speed cameras and are processed into fluctuating components of pressure. However, the nature of the intensity method also requires a separate steady state (time mean) pressure measurement to be obtained. This steady state measurement has typically been obtained using a separate set of PSP equipment that uses the ‘lifetime method’, which uses pulsed excitation to measure paint decay lifetime. If the lifetime method were implemented in the high-speed uPSP system, both the fluctuating and mean components of pressure could be obtained with a single system. This would greatly streamline setup, operations, and processing. In this paper, we describe work performed at the Fluid Mechanics Laboratory at NASA Ames to implement the lifetime method in our uPSP system. The uPSP acquisition system uses Phantom v2512 high-speed cameras, and it was initially uncertain if results of adequate quality could be obtained - their high framerate comes at the cost of several undesirable characteristics, which are explored in this paper. It was also uncertain if illumination using LED lamps, rather than a stronger source such as lasers, would be adequate. The data acquisition and data processing are discussed and the results analyzed. It was found that satisfactory lifetime method results can indeed be obtained using these high-speed cameras and LED lamps. This will allow the uPSP system to be greatly simplified and will have a large operational impact on how uPSP data is acquired in future wind tunnel tests.
Document ID
20220018209
Document Type
Conference Paper
Authors
David D. Murakami
(Ames Research Center Mountain View, California, United States)
Marc A. Shaw-Lecerf
(Ames Research Center Mountain View, California, United States)
E. Lara Lash
(Ames Research Center Mountain View, California, United States)
Kenneth R. Lyons
(Ames Research Center Mountain View, California, United States)
Nettie H. Roozeboom
(Ames Research Center Mountain View, California, United States)
Date Acquired
December 1, 2022
Subject Category
Aeronautics (General)
Optics
Fluid Mechanics and Thermodynamics
Meeting Information
Meeting: AIAA SciTech Forum and Exhibition
Location: National Harbor, MD
Country: US
Start Date: January 23, 2023
End Date: January 27, 2023
Sponsors: American Institute of Aeronautics and Astronautics
Funding Number(s)
CONTRACT_GRANT: NNA16BD26C
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Technical Review
NASA Peer Committee
Keywords
Pressure Sensitive Paint
High Speed Cameras
Noise
Wind Tunnel Testing
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