Boundary Lyer Theory

216 X. Approximato n~ethods for steady eqllations d. Further examplcs 217
well as in the shearing stress are concerned, and predict an earlier point of separation.
W. Schocnauer found that thc separation angle is at$a = 1045Oas = 109TP'
ol~t.ainat1 with t11c nit1 of the l'ohll~auscn approximation and $s = 108.8O suggested by
tllc series cxp:ansion cont,inuctl up to the term z". A comparison between t,hc vclocity
tli~t~ribut~ions, IGg. 10.8, leads to the conclusion t,l~at there cxist,s almost perfect
agrwmrnt. hrf,wcrn t,Im exn.ct solut.ion and the npproxiniation in t.hc m.ngc of angles
0 < 4 < !)On, t,lrat. is in t,l~c range of acc:clcrat,ctl c*xt.crnal flow. I 12 (K > O.O!IR), because the plot of X against A !.urns at, this poit~l
(Table 10.2) and cantlot, tl~rmlore, be contirlucd 1)oyond K -- 0.0!15. Moreovor. for A > 12
the vrloriby prnfilns l~rco~no r~nnrrcpt,al)le as t.liry rontnir~ point,^ for \vl~irl~ ti/II -.- I (Fig. 10.4).
'I'l~rar cliffioid!.ira arc obviatcd wl~cr~ cqli. (10.37) is IIRC~.