Measuring and testing – Frictional resistance – coefficient or characteristics – Lubricant testing
Reissue Patent
2005-02-10
2010-06-29
Caputo, Lisa M. (Department: 2855)
Measuring and testing
Frictional resistance, coefficient or characteristics
Lubricant testing
Reissue Patent
active
RE041398
ABSTRACT:
A method is provided to select appropriate material properties for turbulent friction drag reduction, given a specific body configuration and freestream velocity. The method is based on a mathematical description of the balance of energy at the interface between the viscoelastic surface and the moving fluid, and permits determination of the interaction of turbulent boundary layer fluctuations with a viscoelastic layer by solving two subtasks—i.e., a hydrodynamic problem and an elasticity problem, which are coupled by absorption and compliancy coefficients. Displacement, velocity, and energy transfer boundary conditions on a viscoelastic surface are determined, and a Reynolds stress type turbulence model is modified to account for redistribution of turbulent energy in the near-wall region of the boundary layer. The invention permits drag reduction by a coating with specified density, thickness, and complex shear modulus to be predicted for a given body geometry and freestream velocity. For practical applications, viscoelastic coatings may be combined with additional structure, including underlying wedges to minimize edge effects for coatings of finite length, and surface riblets, for stabilization of longitudinal vortices.
REFERENCES:
patent: 3435796 (1969-04-01), Merrill
patent: 3516376 (1970-06-01), Kowalski
patent: 4771799 (1988-09-01), Baxter et al.
patent: 4865271 (1989-09-01), Savill
patent: 4932612 (1990-06-01), Blackwelder et al.
patent: 5020561 (1991-06-01), Li
patent: 5133519 (1992-07-01), Falco
patent: 5342465 (1994-08-01), Bronowicki et al.
patent: 5619433 (1997-04-01), Wang et al.
patent: 6024119 (2000-02-01), Kirschner
patent: 6287664 (2001-09-01), Pratt
patent: 6332593 (2001-12-01), Kamiadakis et al.
patent: 6357374 (2002-03-01), Moore et al.
patent: 6892989 (2005-05-01), Whitmore et al.
patent: 2002/0173569 (2002-11-01), Karhu et al.
patent: 2005/0032029 (2005-02-01), Trunk
P.A. Davidson,Turbulence—An Introduction for Scientists and Engineers, 2004, pp. 130 and 131, Oxford University Press, New York.
A.D. Young,Boundary Layers, 1989, p. 12, AIAA Education Series, Washington, DC.
May Carol L.
Voropayev Gennadiy A.
Arnold Bruce Y.
Arnold International
Caputo Lisa M.
Cortana Corporation
Davis Octavia
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