-15- 261 



which we shall use are 



L = >3 

 (2.6) 



C = L 



5E 







€ 



where P Is the hydrostatic pressxire at the center of 

 the explosion, and p is the density of vmtero These 

 scaling factors are advantageous because they have a simple 

 physical interpretation intimately connected with the motion 

 of the bubble. It will be seen in part III that L Is the 

 maximum radius of the bubble if the internal energy of the 

 gas could be neglected. Actually the maximum radius is 

 approximately •92L. Also, it will be shown in part III that 

 the time scaling factor C represents 2/3 of the period of 

 pulsation of the bubble if no outside influences such as rigid 

 walls or free surfaces are present. 



The energy equation in terms of the non-dimensional 

 variables becomes 



(2.7) a'[l=.p].a'.0^=l, 



where the "dot " denotes differentiation with respect to the 

 non-dimensional time t. 



4, The scaling factors and the internal energy of the gas for 



T. N. T. 



It is desirable to express the scaling factors L,C 

 in terms of the mass of explosive and the depth of the explosion. 



* These scaling factors differ from those used by G. I. Taylor 

 m [ 3] . 



