Cavitation Inception on Rough Bodies 



" 0.1 



15 20 



WATER DEPTH IN FEET 



Fig. 5 - Effect of geometry of isolated roughness elements 

 on cavitation inception (C = -0.5, S = 0.4 in., m = 7, T = 54°F) 



these curves might very well apply to large sonar domes on destroyer leaders 

 or frigates. A temperature of 54 °F was used as a representative temperature 

 of the ocean. 



Figures 4 and 5 compare the cavitation inception properties of the five dif- 

 ferent roughness geometries. The critical roughness heights for cavitation 

 inception are plotted as functions of the flow velocity for two submergence 

 depths in Fig. 4 and as functions of submergence depth for three flow velocities 

 in Fig. 5. It is evident from these figures that two-dimensional triangular 

 roughness elements are most critical for cavitation inception. The cylinders 

 and cones, which also present sharp discontinutities to the flow, are the next 



191 



