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Predicting Transition from Laminar to Turbulent Flow over a SurfaceA prediction of whether a point on a computer-generated surface is adjacent to laminar or turbulent flow is made using a transition prediction technique. A plurality of boundary-layer properties at the point are obtained from a steady-state solution of a fluid flow in a region adjacent to the point. A plurality of instability modes are obtained, each defined by one or more mode parameters. A vector of regressor weights is obtained for the known instability growth rates in a training dataset. For each instability mode in the plurality of instability modes, a covariance vector is determined, which is the covariance of a predicted local growth rate with the known instability growth rates. Each covariance vector is used with the vector of regressor weights to determine a predicted local growth rate at the point. Based on the predicted local growth rates, an n-factor envelope at the point is determined.
Document ID
20150003117
Acquisition Source
Langley Research Center
Document Type
Other - Patent
Authors
Rajnarayan, Dev
Sturdza, Peter
Date Acquired
March 18, 2015
Publication Date
September 17, 2013
Subject Category
Fluid Mechanics And Thermodynamics
Report/Patent Number
Patent Application Number: US-Patent-Appl-SN-13/069,374
Patent Number: US-Patent-8,538,738
Funding Number(s)
CONTRACT_GRANT: NNL08AA08C
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Patent
US-Patent-8,538,738
Patent Application
US-Patent-Appl-SN-13/069,374
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