a - b 



?«=- 



b\y\ 



2.y^^^~^ 



'y + c 



V 



aiyi 



- b\ sin a 



On the cylinder itself a' = a, b' = b, x = a cos rj, y = b sin ??, hence 9^ = 0, 



[83q] 



[83r] 



^t = 



ibUc^yY' 



y 



U {a + b) ( — cos a - 



r 



277- 



[83s] 



and q - \g,\. If F = 0, stagnation points occur where y/x = (b/a) tana . For comparisons with 

 experiment, see Zahm, References ICl and 102. 



Examples of the streamlines for F = and a = deg, 45 deg, and 90 deg are shown in 

 Figures 132, 133, and 134. Here a/b = 2, ^^ = coth~^ 2 = 0.549. In two cases only half of 

 the symmetrical diagram is shown. In two cases the excess of pressure above that at infinity 

 is shown, for steady motion, at points on the axes or on the cylinder, by curves labeled 

 p - p . For points on the y-axis, p - p is plotted horizontally from the y-axis as a base 

 with positive values toward the right. In Figure 135 the calculated pressure on an elliptic 

 cylinder with F = a =0, represented by the broken curve, is compared with observed values 

 in air at 40 miles per hour, which are represented by small circles (from Reference 101). 



Figure 132 - Flow past an elliptic cylinder, incident parallel to 



the major axis (a = 0), and pressure p on the cylinder or at 



points on the x or y axis. 



199 



