Figure IS. Mathematical model for flow past 

 yawed wedge. 



Figure 16. Variation of lift curve slope with 

 wedge angle (/?2). 



This yields 



C L — Cn — Cdo 



s 

 = 2 — cos 2 /3 — Coo/radian 

 V 2 



= 2(1 - C Do ) cos 2 0- C Do 



(5) 



and substituting values of C Do , good agreement with experiment is obtained — not only 

 for moderate cone angles, but even over the whole range. (The good agreement for 

 large angles may be due to the cos 2 /? term which —> as (3 — > 90°.) 



d. Breakdown of the Axi-symmetric Cavity. Conditions at the rear end of a 

 cavity are important as they determine the rate at which the air contained in a detached 

 cavity is dispersed, and hence the rate of collapse of the cavity. For fairly long cavities 

 it was observed by Swanson and O'Neil (1951) that a pair of hollow core vortices 

 was generated at the rear of the cavity (Fig. 19). A theoretical study of this problem 

 by R. N. Cox and W. A. Clayden (1955) showed that the circulation round the vor- 

 tices could be related to the buoyancy lift on the bubble. This flow model gives a more 

 satisfying physical explanation for a resolution of the 'Brillouin paradox' than does 

 the artificial — though extremely valuable — conceptions of the Riabouchinsky image 

 body, or the re-entrant jet of Gilbarg-Rock. 



230 



