Boundary Lyer Theory

404 XVII. Oriein of tnrbnlencc TI
Fig. 17.5. Sl~nrlograpl~ pict,r~re of reverse t.ransit.ior~ front t~rtrl)r~lnnt, to l:rn~it\ar flow in n \~orr~tdary
layer it1 s~~pcrsonio flow rot~r~d a corner at. M = 3, nfkr J. Skrnl)erg [215j
wig. 17.1;. Srltrtitnt.ic rrprcncnl,nt,ion of
the flow in t.hc Imr~ndnry hyrr in RII~Waonir:
flow nrot~ld n vornrr, nf1.w .I. Sternberg,
c/. Fig. 17.5
t l'hr vnlr~c R , - A45 givcw hcrc for A - 0 tliffcru so~ne\vhnt from the value 520 givrn previor~uly
in JGg. 16.1 I. 'l'ltiu is duc 14) the clilli:rc~~cc bctwccn tl~c exnct I%lnniun vrlocity profile
11srd ~wvvio~~sIy nntl nll ~b~~l~roxiltl:ttr ollr rlltl~lo,vcd for 1.h ~)rol~ar:bt.io~r of rig. 17.2.
graph of wn.ve-like nt.rcnk I~IICR in a writer vl~n~it~el ~d~l.~illt*d with 1,h? nid of lrhc t.cll~~ritt~tt 111t?t11od
by IT. X. Worttnnnn 1257, 2581; di~trlrbnitco crcnkd nrlificinlly hy n.11 oscill:~t.ing sllrip (3 x A00
>: 0-03 III~I). The strip is lovntcd nt n st.iiIiou wltnre R1 =- 750; the at,rcnk li11c8 itre c:rnnlrtl xt
R, == 950 (Irft. border of figure). The rolling up ofntrenk linrs tlow~~ntrrn~~t
instnldit,y of the prrt.t~rlmt.ion wnres. 'l'hc figrlrra t1c11ote 1listnnc.r~ ill rm
in n rotwicqrlrtlre of t,l~e
Tho phot.ogra,pli of Fig. 17.7, tdtcn by F. X. Wortm~nttn [2M. 2561 it1 a wn.t,c:r
cl~anncl conveys n clcar iniprrssion of unsf.cLl~lc oscillnlic)its in n. 1ntni11n.r I)ollntla.ry
Inyw. The picture was obtained by the tolluri~~rn ~nt:t.hotl /256]. l'hc a.rt.ificnl dist.nr0nnces
were generated wit,h t,ho aid of an oscillnt.ing strip placctl near t.hc nall,
in n mnnnrr siri1ila.r t.o l,hat crnploycd by Schulmr~cr. ~lld ~krr?tnst,atl ant1 tIcseril)~(1
in Chap. XVI. 'J'hc ~)rrssnrc rise a.long thr wirll is so srnnll t.l~nt. tho I'ol~lhn~tsc~~ prntnct.rr
from rqn. (17.3) llxs t.11c vnlnr A - --8. At. f.hr shlion whrrr the. tlist.t~~.l):~nrc
is gctivtnl~tl I.II(. 1oc:trl Il.c!ynol~ls IIIIIIII)I'I. 1111s 1.l1r \ ~ ~ I IRbl I \ - 750, IIII~I l.11(* (litllwsiol~lcss
wa.vrlt:~~gLlt of the tlist,url)nnco is nl (TI -= 2 nOl/l -- 0.48. This [wir~t. is loc.:~.t.ctl
far in thr ~lnst,nl)lr ficltl of Fig. 17.3. '1'11~ instmit.n.ncv)~ts s~lnpsl~o; of I.Itv sl.rcdc linrs
in Pig, 17.7 sl~n\vs 111~ fii1:11 11I1nsc ol' Iht% t~\vo-tli~~~ct~sio~~;~l
~I(:~~~~IoI~~II~*III~
of' 1111. (listrrr1tnnc:c
nI)out, 20 wnvc4rngt.11~ tlownst~rc~nrii of (.l~c osril1:rf ing strip. 'I'his tlisl.nr~~:~nrc:
nmplifirs in cornplt~t,~ n.grrrmrnt of l.l~rory wil,li c!xl~rritnri~l.. 'I'l~c tl~~et,~~n.licin, wl~icl~
is stmill two-tlirnrnsior~nl near t.hc Irf't. rtlgo of I.IIc pict,ttrr I~reonws tlisl.or1.cd in i1.s
rnitltllc by 1.Iic: o~~cotning longitutlir~n.l vort.icos. At thr right, ctlgc! ol' I,III% pit:I.ttt.r if. is
nlrrntly ~)ossil)lr t,o tlisccrn "t,~~rl~~tlent~ rows". 'l'l~is ronfit~tns our 1.c.lnn.14ts (YIII(:W.II~II~
t,l~rcc-tlirr~rnsiotinl tlist,urbanccs givrn nl, t.hr cwl of t,his cli:tpt.cr.