LOS ANGELES AND LONG BEACH HARBORS MODEL STUDY. REPORT 4. MODEL DESIGN

This report describes the design of the Los Angeles and Long beach Harbors hydraulic model for investigation of harbor oscillation characteristics of the existing harbor and for evaluation of various proposed harbor modifications. The effects of wave refraction, diffraction, viscous friction, wave reflection, wave transmission through the harbor breakwaters, wave filters, and wave absorbers were considered. Wave generator design, automated model data acquisition and control, and model data analyses are also described. This report is the fourth in series Technical Report H-75-4 published under the general title Los Angeles and Long Beach Harbors Model Study. A model distortion ratio of 1:4 and a vertical scale ratio of 1:100 (1:400 horizontal scale ratio) were selected to minimize the model area and to provide a vertical scale ratio where accurate model wave measurements could be assured. The model reproduces approximately 253 square miles of prototype area. Model limits were selected to enclose a strong convergence zone seaward of the harbor breakwater. Adjustment of the initial generated wave-front position in the model was necessary to compensate for model distortion and the maximum model depth of -300 ft mllw. The electrohydraulic wave generator used in the model study is composed of 14 separate 15-ft units for a total wave generator length of 210 ft and is capable of (a) generating waves with a prototype period ranging from 15 to 600 sec, (b) generating a wave with small variation in period and height between units, (c) defining resonant response over a narrow period band, (d) generating a variable wave height along the wave front, and (e) generating a curved wave front.