NSWC/WOL TR 76-155 



The firing delay depends on the firing circuit, length and 

 type of firing line, and the detonator. For the 1975 tests we 

 estimated from a comparable test setup that 



FIRING DELAY = +0.31 + 0.05 milliseconds 



(D2) 



The correction, VEL. CORR. , to At , must be calculated. 



sound 



It is given by the following equation 



VEL. CORR. = - -- 2 - 

 c 



r R/Ro 



u 





L l 



,R 



Co / K, 



_ c °\ 



(D3) 



where 



R = radius of the charge 



c = sound velocity in the water 



U = shock velocity in the water 



R = radial distance to gage 



D = detonation velocity in the charge 



The first term inside the brackets represents the contribution due 

 to the water shock while the second, that due to the detonation wave 

 Equation D3 was derived from the sketch shown in Figure D-2 . 



The integrand in Equation D3 was obtained by fitting 



results from a hydrodynamic code calculation for pentolite by 



12 

 Sternberg and Walker with the following equations 



12/ 



Sternberg, H. M. , and W. A. Walker, 1971, "Calculated Flow and Energy 

 Distribution Following Underwater Detonation of a Pentolite Sphere", 

 Physics of Fluids, September 1971 



D-4 



