EXPERIMENTAL STUDY OF WAVE-DISSIPATING BLOCK SHAPE’S EFFECTS ON ENERGY DECAY IN OPEN-CHANNEL FLOW

Abstract

 In the performance design of offshore structures, little consideration has been given to the shape of the wave-dissipating block. It is necessary to evaluate the shape characteristics in order to perform more accurate performance verification. In this study, we conducted PIV measurement of the flow around a sloping breakwater model in open channel flow for three types of blocks. The effect of the difference in block shape on the energy decay of the surrounding fluid was evaluated, and its reflection in the formulas for prediction of wave transmission coefficient was examined.

 As a result, it was found that the characteristics of the flow velocity, turbulence intensity, and Reynolds stress distributions after passing through the sloping breakwater are changed due to the difference in shape of the block. The shape factor K_s reflects these results was applied to the formulas for prediction of wave transmission coefficient. As it turned out, a calculated value has high correlation with experimental value.