Jets and Shock Waves from Cavitation 



,2mm y 



RAGGED JET sCALES^StAL 



SPEC 202 

 STAINLESS STEEL 

 3780 fps 

 GOOD JET 



1737 



Fig. Dl - Comparison of water jet im- 

 pact damage with cavitation pit profiles 



(a) water impact profiles from DeCorso, 



(b) cavitation pit profiles from Robinson 



our own laboratory from a somewhat similar experiment (Fig. D2).* Since the 

 cavitation microjets also emanate from an accelerating concave liquid surface, 

 is not the similarity perhaps more than coincidental? 



Finally, as shown by Dr. Ellis's Fig. 9 and also in various pictures of non- 

 symmetrical collapses which we have obtained! there is an indication of a pro- 

 tuberance both on the side of the presumed jet penetration and on the opposite 

 side. We have interpreted these to be local cavitation generated by the passage 

 of a high- velocity jet through a relatively quiescent liquid. Thus there is an in- 

 dication of local high liquid velocities both on the side toward which the jet is 

 traveling as well as that from which it has come. From simple considerations 

 of continuity this does not appear to be necessarily unreasonable. 



*F.G. Hammitt, J.F. Lafferty, M. Pitek, P. Drucker, H.G. Olson, and M.J. 

 Robinson, "A Facility for the Study of High Velocity Jet Impact," ORA Techni- 

 cal Report 08153-2-T, Nuclear Engineering Departmient, University of Michigan. 



tH.G. Olson, "High-Speed Photographic Studies of Ultrasonically-Induced Cavi- 

 tation and Detailed Examination of Damage to Selected Materials," Ph.D. Thesis, 

 Nuclear Engineering Department, University of Michigan, Aug. 1966. (Also 

 available as ORA Technical Report 07738-2-T, University of Michigan, Aug. 

 1966.) 



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