21 



or a stagnation point (the latter found also by von Kdrm^n'*'* and included in the more general 

 class of cavities of constant shape found by Gilbarg); the second comprises cavities for 

 which the free streamlines cross the axis of symmetry and are, thus, not physically realistic. 

 In addition to the above detailed computations, he briefly indicated the method of extension 

 of these results to arbitrary polygonal shapes and also to asymmetric polygonal shapes. 



CONCLUDING REMARKS 



An attempt has been made to present a more unified outline of the various cavitation 

 processes and to indicate, approximately, the progress on the various topics in this outline. 

 It is hoped, however, that some old problems which still require investigation and some new 

 ones have been more clearly pointed out in the course of this survey. Although no direct 

 mention of damage or cavitation prevention has been made, the remarks of Reference 3 re- 

 garding the mechanisms need no material modification. However, direct work on damage of 

 specific materials is still of much importance and programs are underway in various labora- 

 tories. 



As a final remark, it might be observed that perhaps the greatest progress in this 

 field in recent years has been in the recognition and more clear definition of the problems 

 requiring investigation. 



REFERENCES 



1. Harvey, E. Newton, Barnes, K.D., McElroy, W.D., Whiteley, A.H., Peese, D.C., and 

 Cooper, K.W., "Bubble Formation in Animals," Jour, of Cellular and Comp. Physiology, 

 Vol. 24, No. 1, August 1944, pp. 1-34. 



2. Harvey, E. Newton, Whiteley, Arthur A., Grundfest, H., and McMillen, J.H., "Piezo- 

 electric Crystal Measurements of Pressure Changes in the Abdomen of Deeply Anaesthetized 

 Animals during Passage of a High-Velocity Missile," The Military Surgeon, Vol. 98, No. 1, 

 January 1946, pp. 509-528. 



3. Eisenberg, Phillip, "On the Mechanism and Prevention of Cavitation," TMB Report 

 712, July 1950. 



4. Taylor, G.I., "The Mean Value of the Fluctuations in Pressure and Pressure Gradient 

 in a Turbulent Fluid." Proc. Camb. Phil. Soc, 1936, Vol. 32, pp. 380-384. 



5. Green, A.E., "The Mean Value of the Fluctuations in Pressure and Pressure Gradient 

 in a Turbulent Fluid," Proc, Camb. Phil. Soc, 1938, Vol. 34, pp. 534-539. 



6. Batchelor, G.K., "Pressure Fluctuations in Isotropic Turbulence," Proc. Camb. Phil. 

 Soc, Vol. 47, April 1951, pp. 359-374. 



7. Townsend, A. A., "The Structure of the Turbulent Boundary Layer," Proc. Camb. Phil, 

 Soc, Vol. 47, Pt. 2, April 1951, pp. 375-395. 



