Accession Number:

ADA247942

Title:

Simple Models for Turbulent Wave-Current Bottom Boundary Layer Flow

Descriptive Note:

Final rept.,

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE RALPH M PARSONS LAB FOR WATER RESOURCES AND HYDRODYNAMICS

Personal Author(s):

• Madsen, O. S.
• Wikramanayake, Palitha N.

Report Date:

1991-12-01

Pagination or Media Count:

151.0

Abstract:

The application of simple eddy viscosity models to the interaction between the turbulent wave and current boundary layer is studied. A comparison of the results of some recent models from the literature with data from laboratory experiments and numerical models shows that none of these models reproduced the data satisfactorily. An improved model, which did not involve any additional fitting parameters, was developed and found to fit the data well for the case of waves and current in the same direction. The inability of the improved model to represent some features of the results of higher order turbulence models for the case of waves at an angle to the current was found to be due to the assumption of a time-invariant eddy viscosity. Therefore, a model that allowed the eddy viscosity to vary with time was developed and solved for the case of a weak current. This time varying model was found to improve the agreement with the numerical model for the case of waves at an angle to the current. Simple, accurate, analytic approximations were developed that allow the solution of practical problems with this model using no more powerful a tool than a hand calculator.

Descriptors:

• *BOUNDARY LAYER
• *EDDIES(FLUID MECHANICS)
• *TURBULENT FLOW
• LAYERS
• PARAMETERS
• COMPARISON
• TURBULENCE
• TIME
• BOUNDARIES
• VISCOSITY
• BOTTOM
• WAVES
• HANDS
• FITTINGS
• INTERACTIONS
• CALCULATORS
• ANGLES
• MODELS

Subject Categories:

• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE