Impulsively Generated Waves Propagating into Shallow Water 



Radial distance along axis: 

 Distance along path: 

 Wave elevation: 

 Offset of path from axis: 

 Source strength: 



r = r'/ho 

 s =s'/h^ 



^ = ii'Ao 

 y = y'Ao 

 w = Y°-Vh 



In the last definition Y is the explosive yield in pounds of TNT, 

 equivalent. For dimensional consistency the exponent should be 1/4; 

 however experiments have shown that exponents from 0,26 to 0,30 

 (depending on the subnnergence of the source) provide better 

 scaling. The value 0.3 is taken here. 



Results of time histories along the axis for three different 

 source strengths are presented in Figs, 5-7: 



Figure 5, small explosion, W = 0,139 



Figure 6, moderate explosion, W = 0.166 



Figure 7, large explosion, W = 0,224. 



-A " OJ^Ojlj). > :J ^J!^MJ^ 



- - r< ^ISjU\AMj^ ca:.TO0^ £IA. 



V^A jix/Ltev^ - -un^lZUv 



"^^^JXKKKKp-- -o^mi^ 



■ ^^^wAZfflZy^^ «i"iyy» 



20 30 40 is eo i5~ 



time — ~ftVg/h„ 



Fig. 5. Prediction of wave system on axis for small explosion 



255 



