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Uncertainty Analysis for Oil-Film Interferometry Skin-Friction Measurement TechniquesOver the past 20 years, the use of oil-film interferometry to measure the skin friction coefficient (C(sub f) = tau/q where tau is the surface shear stress and q is the dynamic pressure) has increased. Different forms of this oil-film technique with various levels of accuracy and ease of use have been successfully applied in a wide range of flows. The method's popularity is growing due to its relative ease of implementation and minimal intrusiveness as well as an increased demand for C(sub f) measurements. Nonetheless, the accuracy of these methods has not been rigorously addressed to date. Most researchers have simply shown that the skin-friction measurements made using these techniques compare favorably with other measurements and theory, most of which are only accurate to within 5-20%. The use of skin-friction data in the design of commercial aircraft, whose drag at cruise is 50% skin-friction drag, and in the validation of computational fluid dynamics programs warrants better uncertainty estimates. Additional information is contained in the original extended abstract.
Document ID
Document Type
Conference Paper
Naughton, Jonathan W. (MCAT Inst. Moffett Field, CA United States)
Brown, James L. (NASA Ames Research Center Moffett Field, CA United States)
Merriam, Marshal
Date Acquired
August 20, 2013
Publication Date
January 1, 1996
Subject Category
Fluid Mechanics and Thermodynamics
Meeting Information
1997 ASME Fluids Engineering Division Summer Meeting(Vancouver, British Columbia)
Funding Number(s)
PROJECT: RTOP 505-59-53
Distribution Limits
Work of the US Gov. Public Use Permitted.