Transformation of Mean and Highest One-Tenth Wave Heights Using Representative Wave Approach

Abstract

Models were studied for computing the mean wave height (H_m) and highest one-tenth wave height (H_1/10) using a representative wave approach. Many researchers have pointed out that the use of a representative wave approach can give erroneous results in the computation of representative wave height transformations. However, the representative wave approach has great merit in its simple calculations. It would be useful for practical works, if this approach could be used to compute representative wave heights. Some researchers showed that the representative wave approach can be used to compute the transformation of the root-mean-square wave height and significant wave height with very good accuracy. However, it is not clear whether the approach is applicable for computing H_m and H_1/10. The present study investigated the accuracy of the calculation of the transformation of H_m and H_1/10 by using the representative wave approach. Laboratory data from small-scale and large-scale wave flumes were used to examine the models. The representative wave height transformation was computed from the energy flux conservation law. Seven energy dissipation models of regular wave breaking were directly applied to the irregular wave model to test their applicability. It was found that by using an appropriate energy dissipation model with new coefficients, the representative wave approach can also be used to compute H_m and H_1/10 with very good accuracy.