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-0.07 -0.06 -0.05 -0.04 -0.03 -0.02 -QOI 



0.01 0.02 0.03 0.04 0.05 0.06 



e^ du 



Pressure Groaient Parameter 



-V dx ' 

 Figure 3 - Neutral Stability Point as Function of Pressure Gradient (Mangier, Ref. 21) 



Ra = 



dU 



[39] 



as a function of a pressure-gradient parameter ^ =^ . The curve shown, which is based on 



V dx 



the stability characteristics of Pohlhausen-type velocity profiles as calculated by Schlichting 

 and LUrich^'^ is applicable to both two-dimensional and axisymmetric boundary layers. 



Unfortunately no theoretical analysis has been developed for locating the point of self- 

 excited transition from the ampliRcation of the ToUmien-Schlichting waves past the point of 

 neutral stability. Experimental evidence^^ indicates a pronounced effect by favorable pressure 



