A. S. Iberall 



for the mean flow. A simple form has finally been found. While not perfect, it 

 may be considered one further element in a sequence of open forms. Expand 

 the mean velocity distribution 



as 



a four parameter family (except for R^^, which is given) with boundary 

 conditions 



cp - 1 for X = +1 (Ro/R„3 - 0) 



•.,;..,■ ....: <P = for X = (Ro/Koo = 1) 



1 dRn 



± g/R„„ = ±N for X =: + 1 ( T^ = + N 



"" ' R dx 



oo 



, 1 ^'^0 

 ^ = g/Roo=+N for x= ±1 ( — -^=-N 



oo 



It can be shown that the solution is 



R + R 



.2M+2 



(The earlier form used in [lO] led to an erroneous value for the propagation 

 constant § — not for x — since the result is sensitive to the velocity distribution 

 in the boundary layer.) 



This equation is a three -parameter representation of the mean flow, con- 

 taining R^j^ the Reynolds number, g the pressure gradient, and an arbitrary but 

 large constant M. 



We know M is large (i.e., the boundary layer is thin) because we found a 

 high peak in Rg" near the wall. 



By setting R^" ' = 0, we can note where this peak occurs. It is found at 



, 2M - 1 , 1 

 2M + 1 M 



i.e., near the wall, if M is large. 



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