Van Mater and Beat 



is a rapid increase in wave height known as "wave peak- up" which 

 occurs just before breaking. The effect has been observed by 

 Le M^haut€, Snow, and Webb [ 1966] . On the basis of the experiments 

 reported in that source, Van Dorn, Le M^haut^, and Hwang [ 1968] 

 state that the increase in wave height due to peak- up is 40% of the 

 linearly computed value. 



Computationally, the wave height computed on the basis of 

 Eq. (12) is multiplied by a factor of 1.40 to account for peak up and 

 tested against Eq, (19) for each point in the spatial and frequency 

 array. If breaking occurs the increased wave height is retained as 

 Hu for use in Eqs , (20) and (21). If no breaking occurs the linear 

 value of wave height is retained. 



The Van Dorn boundary dissipation equation for impermeable 

 bottoms and modified for a wide basin is: 



H2 _ 



H, 



= ^"P jl {hT [(t) ^'^2^2 - '^.h,) - (^2 - '^i)] j (22) 



where, v = kinematic viscosity of water and points 1 and 2 are 

 successive points in the direction or propagation. 



VI. RESULTS AND DISCUSSION 



In this section the computer program predictions for three 

 source strengths, corresponding to small, moderate, and large 

 explosions, will be described and discussed. No experimental data 

 are included but comnaents will be made on the agreement between 

 the predictions and experiments which have been conducted. 



The theory and the computational procedure outlined in the 

 preceding sections are applicable to any arbitrary bottonn profile 

 with parallel straight contours and gentle slopes. However, to 

 compare the theory with experiment a specific bottom profile, that 

 of a test basin at the Waterways Experiment Station, Vicksburg, 

 Miss, , was introduced as an input to the computer program. Through 

 the courtesy of that laboratory access was granted to data from a 

 series of experiments conducted there. The data has not yet been 

 formally published by WES at this time, so it cannot be reproduced 

 here; however general comments on the agreement between predicted 

 and experimental results will be made. 



The computer results are non-dimensionalized on the basis of 

 the water depth at the explosion, hg. Previous notation is used 

 except that the water depth, h, is taken as the depth at the origin. 



254 



