EVALUATING SCALE EFFECTS ON EXPERIMENTAL STUDIES OF NONLINEAR UNSTEADY FLOW REGIMES

Rubble mound breakwaters are frequently constructed with a core of quarry run materials; whose geotechnical parameters do affect the structure’s armours stability.To inhance stability, therefore, the socalled added mass of the core materials due to oscillatory unsteady loadings should be determined experimentally. This is commonly accompalished by means of hydraulic model studies which, in turns, necessitates considering a scale effect when model outputs are to be interpreted. This paper describes parts of an analytical evaluation of transitional scillatory unsteady flow regime through coarse porous media in an attempt to develop a modelling law based on similarities between hydraulic behaviours of model and prototype. A non-linear analysis approach based on the so-called modified Forsch-Hiemer equation has been employed in developing necessary equations needed for the scale effects assessments. The extent of validity of findings in enabling correct interpretation of experimental results have been examined using available data published by previous researchers in the field of rubble mound structures.

Keywords:

Scale effect , Oscillatory unsteady flow , Rubble mound breakwaters