Drag measurements of flat plates with uniform injection of polymer solutions and their direct application to the wall

ViL

1975

Drag measurements on flat plates with üniform injection of

lyxner solutions and their direct application to the wal].

b.y

.Kim and T.Tagori

_Lab.

y.

_{Scheepsbouwkund}

(presented at Ann.Meeting Japa .Soc.Mech.EngpOc1t,96,

_ii

_i

and. No.1 Meeting,JTTC,Feb.1970)

_{iecnniscne nogescnoo}

The applicability of so-called Toms phenomenon to the turbueUf

boundary layers on flat plates was stud.ied experimentally in. two

cases.

The one is the uniform injection of polymer solutions into the turbulent

boundary layer on. a flat plate through its porous wall.

_{The other is}

the direct application of polymer solutions to the wall of

_{a flat plate.}

The experimental apparatus,condi.tions and.results

_{are briefly summarized.}

,

in the following.

CHIE

Nomenclature

Cf:total skin friction coefficient(water density is used)

Re:Reynolds number(water viscosity is used.)

U:water flow velocity(m/sec)

T:water teinperature(

C:conoentration. of solution(wppm or

r*:rate of solution. mn.jeotion(co/seo)

V:volume of sólution applid.i the

_all(A)c

t:thiokn.ess(mm)

Tab.1 Experimental cond.ïtions

injection case

_{application case}

polymer

_{polyethylene oxide(molecular weight:3millions)}

solvent

_water

0(water).10O30O,5Oowppjn

1.0,5.0%

30 -.-. 400

.0.3 ...1.3

circulating water

channel

0.5

1.3

Lab,,

a.Zors part of plate(woocìer4wedge-shaped;300x415,max.t=30) b.main part of plate(formed. with wooden frame porouT.!all;

1900x415x30)

c.porous part of p].ate(formed with two AS rosin plates(t=5) eontani'ìg 20 mm clearance between. them;1800x316x30)

d..rear part of plate(wooden,wsd.ge-shaped.; 300x41 5,max.t30)

e.storetank for

solution or

g.f].oat b.paralle]. guide i.spring j.transd.ucer

k.turbulence 8timulator l.balance m,head.. tank

n.elsctrical circuit o.record.er

p.levsl

The unit

of all numbers d.s mm.

The wooden parts are &1]) coated. with. paint.

The resistance is measured

on b.

The apparatus for the application case is not presented, for it differs from that for the

injection

plttCxø

azid;.

Fig.2 Total skin friction coefficient for the injection case

O

o

o

o

o

o 105

000

e

-o

e

0.5

_1.5

e

O

o

e

e

o

o

o X iO

o.S

O

o

4

i

o

-

Schoexihe'rr's

line

0.5

o

0

o

Fig.5

Total skin friction coefficient for the injection ce

ob

0000000

o

o

o

o

0

a15

e.,,

00

o.,

0'-'

0

G

G

1.0

_1.5

2.0

2.5

o

o

area of wetted. stLrfacèI1.Om2

a

I

mean line for no application case passage of time 1SL V&2J ait c _WLQ.W.

Aticn