Ellis 



X 



wrrr 



*i 



Fig. D2 - Monroe-type jet from an air-gun 

 momentum exchange device 



DISCUSSION 



R. Hickling 



General Motors Research Laboratories 



Warren, Michigan 



Professor Ellis's work over the past few years has clearly Indicated the 

 essentially asymmetric nature of cavity collapse and the undoubted role that 

 liquid impact plays in the cavitation damage process. The lack of symmetry in 

 the collapse of a cavitation bubble, however, does not necessarily imply that 

 centers of high compression cannot occur within the collapse. One can easily 

 imagine an irregular nonspherical collapse that may involve several centers of 

 high compression as well as the liquid impact effects discussed in Professor 



156 



