517 



Author's Reply 



J. H. J. van der MEULEN 



The author appreciates Dr. Chahine's conraients 

 and would like to point out that the principal aim 

 of comparing the cavity growth on the blunt nose 

 with theory was to show that the travelling bubble 

 type of cavitation is more related to bubble dynam- 

 ics than to boundary layer phenomena. 



The surprising observation (Figure 31) that 

 the shape of the attached, growing cavity is a 

 spherical segment is, to a certain extent, consis- 

 tent with the observation by Dr. Chahine (1977) 

 that the growth of the lower part of a bubble below 

 a free surface is not influenced by the presence 

 of the free surface. 



It seems most unlikely that the presence of 

 gas originating from a small stream nucleus or from 



diffusion may have affected the growth of the cav- 

 ity during the observation period. Oldenziel (1976) 

 has shown that such effects can be neglected for 

 explosive bubble growth. 



REFERENCES 



Chahine, G. L. , (1977). Interaction between an 

 Oscillating Bubble and a Free Surface. J. Fluids 

 Engng., Trans. ASME, 99, p. 709. 

 Oldenziel, D. M. , (1976). Gas Transport into a 

 Cavitation Bubble during an Explosion. LAHR Symp. 

 on Two Phase Flow and Cavitation in Power Genera- 

 tion Systems. Grenoble, France. 



