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- John A. Chapman
- Department of Bioproducts and Biosystems Engineering University of Minnesota Saint Paul Minnesota Minnesota USA
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- Bruce N. Wilson
- Department of Bioproducts and Biosystems Engineering University of Minnesota Saint Paul Minnesota Minnesota USA
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- John S. Gulliver
- Department of Civil Engineering University of Minnesota Minneapolis Minnesota USA
抄録
<jats:title>Abstract</jats:title><jats:p>This paper compares parameters that characterize vegetation flexibility effects on flow resistance and drag. Drag forces have been measured in a flume for simple cylindrical obstructions of the same shape and size but with different flexibility under several flow conditions. This data set is used to fit drag parameters and to relate their value to flexibility through the Cauchy Number. A formulation is presented where the drag coefficient is evaluated as a function of a new calibration velocity parameter which is related to the elastic modulus of the obstruction. While the use of a Vogel exponent and reference velocity provides a similar response, the reference velocity when used is somewhat nebulous and appears to have a critical impact on the parameter and the drag force calculated. The proposed formulation for drag reduction is more consistently estimated for the range of flexibilities in this study.</jats:p>
収録刊行物
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- Water Resources Research
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Water Resources Research 51 (5), 3292-3302, 2015-05
American Geophysical Union (AGU)