Accession Number:

AD0733873

Title:

Water Wave Transmission through and Reflection by Pervious Coastal Structures.

Descriptive Note:

Research rept. (Final),

Corporate Author:

ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS

Personal Author(s):

Report Date:

1969-10-01

Pagination or Media Count:

64.0

Abstract:

An expression is given for the resistance of free surface flow in a porous medium, such as a rubble-mound breakwater, in terms of the density of the fluid, the approach velocity, the grain diameter of the material in the breakwater structure, and a resistance coefficient which is a function of Reynolds number of the flow. Tests indicated that the length of the structure relative to the grain diameter is an important factor in determining the resistance of free surface flow in a porous medium. A certain ratio between the length of the structure and its grain diameter must be reached before the structure can be treated as a porous medium. An expression derived by Dr. G. H. Keulegan for damping of translation waves by screen filters was modified to give the transmission coefficient of surface waves propagated through a porous structure. The constants in this expression were also found to be a function of the length of the structure relative to the grain diameter. Measured and computed values of wave transmission coefficients agreed well. Author

Subject Categories:

  • Civil Engineering

Distribution Statement:

APPROVED FOR PUBLIC RELEASE