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7.5 Applications of BLP 233

1.5

1.0
U e
0.5

0.0 J i L_
0.0 0.2 0.4 0.6 0.8 1.0
(a) x/2a

y/2a o.O

(b) x/2a
Fig. 7.7. (a) Inviscid velocity distribution about (b) an ellipse of thickness ratio 0.25.

5.0 T

784

Fig. 7.8. Variation of the wall shear parameter /£J over the ellipse at two Reynolds num-
bers.

With flow deceleration, / ^ begins to decrease, which can lead to flow separa-
tion at some ^-location if transition does not occur. The calculations in Fig. 7.8
6
show that for R^ a = 10 , laminar separation takes place at x/2a — 0.784. If the
flow calculations were not performed for turbulent flow at this location, they
would have been terminated due to the singular nature of the boundary-layer
equations for a specified external velocity distribution. With transition speci-
fied at the location of laminar separation, calculations can then be performed
with wall shear parameter increasing with increasing x/2a, reaching a maximum
around x/2a = 0.90 and then beginning to decrease quickly with turbulent-flow
separation taking place at x/2a = 0.91.