Record. 



xxxiu 



9u u 9w , , , , ..... 



where A = ^r- + - + tt- ' and the problem consists m mte- 



97' r 9z ^ 



grating the differential equations 



(2) 



$ /9u, w,\ Sht, ^ ^w 



ii' 9 I 9w 





5«2 



+(''+m|(|'+?)-o 



where the function 

 (3) 



/3ft)^ 



8(2/i+X) 



has been introduced in place of ii. At the same time the 

 following surface conditions must be satisfied : 



I. Full disc (0 <r^i?). 



TV = for r = i?, 



zz^=^ tor z = dz h, 



rz=0 for r =B and for z = zth. 



II. Perforated disc (B,<r<B,). 



rr = for r = R^ and for r=B^, 



zz = Ofor z = ±:h, 



rz =Oforr=i?j,forr= i? and foTz=zth, 



It can be shown that the followinor formulas 



(4) zv 



2/1 + \) ^ |^^i»''A 



■Ui,r) + Jijr^(^,r) 



(ef*^-e-f'^) 



•'/,(%»•) + 5{r/r,(%r) 



(e''^-e-'l^\ 



