594 



FIGURE 4. Comparison of present theory and numerical 

 experiment of Zeman and Tennekes (1977) . The curves 

 correspond to values of S in (65) . 



most important comparison, however, is that the 

 curves of Zeman and Lumley for various Sp collapse 

 rather well when plotted against t/Sq instead of t 

 as in Figure 1 of Zeman and Lumley. Conversely, we 

 may reproduce Figure 1 of Zeman and Lumley together 

 with plots of D/Dq in (65) for the same values of 

 Sg chosen by Zeman and Lumley. This is shown in 

 Figure 4. The agreement is good, especially at 

 large stabilities where the approximation in (65) 

 should be best. This indicates that the two models 

 have some similar features. 



ACKNOWLEDGMENT 



This research was supported by the National Science 

 Foundation under Grant Nos. ATM76-22284, ATM76-04050, 

 and OCE76-18887, and by the Office of Naval Research, 

 Fluid Dynamics, under Contract No. N00014-75-C-0805. 



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