238 



SHOCK WAVE MEASUREMENTS 



a single curve, and the equation of this curve then specifies the para- 

 meter completely for the particular explosive. 



I 



ifn^ (lii/m 

 TIME CONSTANT /W* 



PEAK PRESSURE 



\ 



.04 .0« S» .1 



H^/R Itrfi/FT) 



IMPULSE / W^ (mTEGRATEO TO 6.7 NOMINAL «) 



ENERGY /M^ (iNTECRATED TO 6.7 NOMINAL •) 



Siiiiilarity curves for sphei-ical pcntolite charges plotted against W^^^/R. 

 Fig. 7.4 (ui)per left), Peak pressure P„.. 

 Fig. 7.5 (upper right), Reduced time constant Q/W^^^. 

 Fig. 7.6 (lower left). Reduced impulse 1 /W^^^ to time 6.7^. 

 Fig. 7.7 (lower right). Reduced energy flux density ^//IP/^ to time 6.79. 



Extensive studies of shock wave similarity have been made at 

 Woods Hole with spherical pentolite charges. Data were obtained 

 from 47 records at 12 distances from 51 and 80-pound charges, and 

 75 records at 4 distances from 0.5, 3.8, and 7.5-pound charges. Peak 

 pressures Pm are plotted against W^^^jR with logarithmic scales in Fig. 

 7.4 and are seen to follow a smooth curve. The solid straight line of 

 slope 1.13 represents the empirical equation 



