At ? = h, 



;i.ioc) 



:.)...-- ;v. Desai and Lieber 



u (h,5, t) =0 ' " t = 



t ■ . ■ ' ' ■ 



-^ . , - - (-u^+lj cos^ •: t > 



V (h,^, t) =0 t = 



= (+G„ + e^) sin ^ t > 



p(h,0,t) - Pg^ + € , a constant. 



e^, e^, and Ep are to be less than the errors of the instruments, so that the 

 solution exhibits asymptotic behavior with increasing values of h. 



It was mentioned earlier that there is a significant difference between the 

 geometric and the dynamic categories of the variables. This difference is that 

 the variables r, 0, and t are measured by instruments which have limitations 

 of accuracy just as great as those instruments used for measuring velocities 

 and pressure. Physically infinite distance, however, does not depend signifi- 

 cantly on the accuracy with which the geometric variables are measured, but it 

 does depend crucially on the accuracy with which the dynamic variables are to 

 be determined. 



Summing up, the dimensional boundary conditions are as follows: 



At r :: a , 



u (a,0, t) = t > 



V (a,9,t) = . t > 



At r = h, 



G(h,(9,t) =0 t = 



= (-u»+ ^u) cos5 t > 

 V (h,5, t) =0 t = 



= (+u<j, + e^) sin 8 t > 



p(h,5,t) = p„ + 2p . t > 



The condition at r = h is to be interpreted as explained previously 



(1.10) 



516 



