Boundary Lyer Theory

468
As :I. srcl~trl
XVI. Origin of tnrbulrnce I
1.0 rcf. 1.471, t,llc cfi:c.f. of' a slighf, st,rc:amwise change in 1.he 1)asic
flow \vns sf~~cli(vl a. nun1l)rr of 1.imcs 12. 4n., 31, 4fi:1., H4a., 1061. As alrrn.11~ point.ctl
ottf. I)y .I. I'~.c~f.sc:l~ [6!)1. Illis c*lT(~t. is stn:~.ll.
.. -. .
'1'11~ VXIIWI~(I ~ O III I 01' I I I O~~.S~IIIIIII(~~~~~I(I
~
w111:tli1111
i~l~rc,d~rc.cvl 11s Ill(. I:wh ol p:~rnllrlisni in Illo hsir IIow r:tn I~rr fot~~id
:IIII/ ,\. II. Kit)l;.l~ (8.4i~J. 'I1111~r0 nrc six :t~l~lilion:~l kr~ns.
~ I : I I I ~ it) ~ % IIN: ,r-~li~wl im 01th~ :~n~plit~~dc oft IIC (lisl~~rl):~nre, t,wo ~ C~IIIS
~IYW twlnl~o~lrnt 01 I I I ~
(lli.14) \!hid) f~o11lai11s I,llr :~~lclilic~n:~l ~ITIILS
in :i IxLpcr I I \\'.S. ~ Saric
'l'\vo trr111s arc: i~~t.~.o(ltcr,rtl hy thr
arc :~~lclod t~y 111:: t,rnns.
velocily ill llw Imsir Ilow, onr Inorr trrnl is d ~ t.o ~ llw c rl):lngc ill t,l~c
uxvc.lrl~gtl~ of Ill(: elistt~rI)nn(~r in tl~c ~:-dirrt4io11 nnd. finnlly, the sixth terln rorrc~sponds to
I~~pl~~~r-nr~l~~r
I~WIIS ill I)or~ntl;~rg-kiycr I Iirory (srr (!I~:ip. jX). 'l'lw presence of s~~rtiori or blowi~~g
~ I V W risc lo I'11rl11rr IWIIIS. An invrstig:ttio~l of tl~r 11111nvrir;il sol~~t~ions of LIIC so nodi if id Orr-
Son~~~~rrl'rlcl IY~II:I~ ion lor v:eriyus vc*loril,v ~~rolilrs of I IIC I":~llrnrr-Siinl~ scvks, 12. 31, IO(i], lniletl
10 ~ I I ~ I I I ( I$111 C ~ :l(l(liIion:~l lwms in IIIOS~ I~:ISVS. For I.llis rc:~son il is ~Iil'liv~~ll to 111:1lie :i ro~np:~risnn
IWI\IIWI s1n.11 so111Iio11s its \wII :IS II~~\\(Y~II 111(v11 :~nd 01r SO~II~~IIIIS 01 Ilw "19in1l)lilir~l" Orr-
Son~~~~rr(i.l~l (~~e~:llion. Ilo~wvrr, in IIIIISI (YISVS 1111. ~I:IIIKV ill IIIV limit (~I'sl:~l~ilily (IIID lo li~rk
nf ~~:w:~llrlis~ll III~IIS 0111 lo I~r~~nall. Il'~~nw~.ir;ll ~ J I I I ~ P I ~ I);~vr
R IIWII givrn 1)y F. C. T. S11en ct.nl.
~85ll~.
The result,s of st.a.1)ilit.y r:slcul:tt~ions porforrnrtl in :~c:c:ortI:rncv wi(.l~ (.In. nrc~f.llotl
tlesc:rilwtl in 1.11~ prccrtling scct,ion arc sllown in Pigs. 16. IO :l.ntl I(i.1 l as wc.ll :IS 'l':~.l)le,
16.1. The st~nl.rl)oinfs along l.llc? cr~rvcs II~c~nlsc~lvc~s 1~*prrsr111. ~IPIII.I.:I.I II~SI~III.II:IIII.I~S; t,I~i:
rcgioti rrnl)rac~d lty the ~ r v cor~~es~)on(ls
c
to nnst~:~.l)lc ~lisl.~~t~l):~t~c~t~s,
:III(I fI1:11, onfsi~lc
it, contains sf.:~l~lc: point,s. ?'hc two l)ranc:I~(~s of the (:II~v~ of nctlt.ra.l st.:ll~ilif.,y f.c.ntl
to\vartls zero a.t, very I;~rgc Itc~y~wlels lu~tnbc~s. 'l'hl: sn~:~llvsl. I