399 



ACKNOWLEDGMENT 



The authors wish to express their thanks to Mr. S. 

 Onuma, the technician of Institute of High Speed 

 Mechanics for his assistance in the experiment. 



NOMENCLATURE 



Cp: pressure coefficient 

 I Cpmin I : absolute value of minimum pressure 

 coefficient 



frp: number of total occurrences of 

 cavitation 



f : number of local occurrences of 

 cavitation at position y 

 width of measuring section 

 cavitation number 

 incipient cavitation number 

 chord length of hydrofoil 

 number of bubbles at radius R 

 static pressure at hydrofoil surface 

 or in free stream 

 static pressure at side wall of 

 measuring section 

 bubble radius 

 local free stream velocity 

 velocity at mid span of hydrofoil 

 installed in measuring section 

 RMS values of turbulence velocity 

 components parallel to free stream, 

 parallel to hydrofoil span and 

 perpendicular to u' and v' , respec- 

 tively 

 X, Y; X, y : co-ordinate system fixed in hydrofoil; 

 the X(x) axis is parallel and the 

 Y(y) axis is perpendicular to the 

 chord of the hydrofoil 



a : attack angle in radian 



p : water density 



A : chordwise distance from leading edge 

 of hydrofoil to rear edge of cavita- 

 tion zone 

 Xq : chordwise distance from leading edge 

 of hydrofoil to inception point or 

 front edge of cavitation zone 



h 



kd 



kdi 



1 



n(R^) 



"0 • 



U: 



Uc: 



u' 



w' : 



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