Boundary Lyer Theory

'1. Skin friction
\VlIat1 t.11~ I)ollntl;lry-Iayw rqust,ions arc int~grnt~ctl, t.hc ~rloc:il.~ tlislribut.ion
(:an I)c tledr~ood, ant1 t,lrr position of the point of srpnmt.ion can be dctcrrninotl. 'I'lris,
in t,urn, perrnit,s us t.o m.lculxt,c lhc visrous tlrng (skin frirt.ion) nrorlrltl t,llo surface
I,y a silnplc process of int,carnl,ing tho sllmring st,rrss nt t.hc wnll over thr surface
of t.lio 1)otly. 'I'l~c sllraring stmss at, t.hc \v:lll is
I
L), = 1) to cos 4 ds ,
1-0
r. The boundary lnyrr along a flnt plnte
e. Tlw bowldnry layer nlong n flnt plnte
il. was cliscussetl hy 11. Bli~si~ts
[2] ill his doclor's t,l~csis at, (hct.t.ingrn. llrt 1.11~
lending edge of the plate L)c at x -= 0, the plate being parnllcl to the r-nxis and
infinit.cly long tlownstmam, Fig. 7.6. Wc shall considor sleatly flow wit,h ;I frcc-
sLroa.m volocitty, [I,, whiclr is pnmllrl to the x-axis. Tlrc vclooity of potmlinl flow
is corlst,xnt in this case, and, thcrdorc, dp/& z 0. Tho boundary-lnper oqnntiorls
(7.10) t,o (7.1 2) I~cco~nc
3 36