Kyung-Duck Suh, Yeul Woo Kim, Chang-Hwan Ji


The friction coefficient in the permeability parameter of a perforated wall has been estimated on the basis of a best fit between measured and predicted values of such hydrodynamic coefficients as reflection and transmission coefficients. In the present study, an empirical formula for the friction coefficient is proposed in terms of known variables, i.e., the porosity and thickness of the perforated wall and the water depth. This enables direct estimation of the friction coefficient without invoking a best fit procedure. To validate the proposed formula, the reflection and transmission coefficients calculated by using the formula are compared with the experimental data for various types of structures including a perforated wall. It is also shown that the proposed formula can be used for irregular waves as well.


perforated wall; permeability parameter; wave reflection; wave transmission

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