solid curve in this figure is the thin boundary layer eddy-viscosity 



model of Cebeci and Smith. The experimental values of eddy viscosity for 



axial locations, x/L <_ 0.873, where the boundary layer is thin, agree 



reasonably well with the Cebeci and Smith model. However, as the boundary 



laver thickens, the measured values of e/Ur 6 become nearly one-fifth of 



Op ^ 



the values for thin boundary layers given by the Cebeci and Smith model. 



The experimentally-determined distributions of mixing length J76 are 



shown in Figure 12. The solid curve in this figure gives the thin boundary 



13 

 layer results of Bradshaw, Ferriss, and Atwell. Again, agreement is 



reasonable for x/L < 0.873 and the experimental values in the thicker 



boundary layers are roughly one-third the values in the thin boundary 



layers. Similar reductions of eddy viscosity and mixing length also were 



1 9 



measured earlier by Huang et al. and by Patel and Lee. The 



experimentally-derived eddy-viscosity and mixing-length data are also 

 given in Table 4. 



^^^^ 



""^\^ O 





^ EXPERIMENTS 



0.704 O 



" /oo .-" 

 - tjP* • • • 



O / \ 



THIN 

 A BOUNDARY 

 LAYERi" 



A 

 4 • A 



\ 



\ 



0.831 □ 

 0.873 <;> 

 0.909 A 

 0.951 A 

 0.987 



A •a 



• 



\ 





/JSk4AA M 



• 



1 1 





A 



1 



V 



r - r,, 



Figure 12 - Measured Distributions of Mixing Length for 

 Afterbody 5 



40 



