Курбатов Ю.Л., Шелудченко В.И., Кравцов В.В. Механика жидкости и газа: Учебное пособие

9

CTPY~HOE

.QBI>1>KEHI>1E

9.1. 3neMeHm&1

cmpyuHo20

OaUJKeHUR

B

pa60qHX

KaMepax

npOMTenJI03HepreTHqeCKHX

YCTaHoBoK

Ha-

6mo).{aeTcx,

KaK

npaBHJIO,

CJIO)l(HOe

).{BH)I(eHHe

no).{

).{eMcTBHeM

CrpyH,

06pa3YIOIlJ,HXCX

npH

HCTeqeHHH

TOnJIHBa

H

B03).{yxa

qepe3

rOpeJIKH.

B

KaMepe

MO)l(eT

6bITb

O).{Ha

HJIH

HeCKOJIbKO

ropeJIOK;

Ha

HeKoTopoM

paccToxHHH

OT

rOpeJIOK

CrpyH

pacnpocrpaHxlOTcx

cB060).{HO,

3aTeM

OHH

HaQHHaIOT

B3aHMo).{eHcTBoBaTb

).{pyr

C

).{pyrOM,

C

OrpaHHqHBaIO-

IlJ,HMH

KaMepy

cTeHKaMH,

C

nOBepxHocTXMH

HarpeBa

H T.).{.;

npH

3TOM

B03HHKaIOT

npxMbIe

H

06paTHbIe

TeqeHHX,

30HbI

nOBblrneHHoro

H

no-

HH)I(eHHOrO

).{aBJIeHHX,

BHxpeBbleH

3acToHHble

30HbI

H ).{p.

CJIO)l(HOe

crpYMHoe

).{BH)I(eHHe

MO)l(HO

paCqJIeHHTb

Ha

OT).{eJIbHble

3JIeMeHTbI:

cB060).{Hble

CrpyH;

crpyl1,

).{BH)I(YIlJ,HeCX B).{OJIb nJIOCKOM

nOBepxHo-

CTH;

CrpyH,

aTaKYIOIlJ,He

nOBepxHocTb

no,n:

yrJIOM;

CrpyH,

6bIOIlJ,He

B

TynHK;

CrpyH,

BTeKalOIlJ,He

B

nOJIOCTb;

B3aHMo,n:eHcTBYIOIlJ,He

Me)l(,n:y

C060M

CTPYH.

9.2. nOHRmue 0 n02paHU'IHOM

cnoe

YpaBHeHHx

,n:BH)I(eHHX

peaJIbHOH

)l(H,n:KOCTH

HaBbe-CToKca

BeCbMa

CJIO)l(HbI,

H

HX

aHaJIHTHqeCKOe

perneHHe,

T.e.

nOJIyqeHHe

no-

JIe"

CKopocTeM,

YCKopeHHM

H ,n:aBJIeHHM ).{JIX

KOHKpeTHbIx

YCJIOBH",

XBJIXeTCX

nOKa

Hepa3pernHMOH

3a,n:aqeH.

B TO

)l(e

BpeMX

npaKTHKa

BbI,n:BHraeT

rH,n:pOra30,n:HHaMHqeCKHe

3a).{aQH,

6e3

perneHHX

KOTOPblX

HeB03MO)l(HO

paCCMarpHBaTb

TaKHe

BOnpOCbl,

KaK

KOHBeKTHBHblH

Te-

nJIO

- H

Macco06MeH,

pa3BHTHe

CrpYM

B

CrrOKOHHOH

H ,n:BH)I(YIlJ,eHCX

cpe).{ax,

B3aHMO).{eMCTBHe

CrpYM

Me)l(,n:y

C060M

H

).{pyrHe

npaKTHQeCKH

Ba)l(Hble

H

CJIO)l(Hble

3JIeMeHTbI

,n:BH)I(eHHX, C

KOTOPbIMH

npHXO,n:HTCX

BCTpeQaTbCX

B

06'beKTaX

npOMTenJI03HepreTHKH.

)l,JIX

QaCTHQHOrO

HJIH

npn6JIn)l(eHHOrO

perneHnX

TaKHX

3a,n:aQ

6blJln

C03,n:aHbI

QaCTHble

TeOpHn,

Han60JIbrnee

3HaQeHne

cpe,n:n

KOTOPbIX

nMeeT

nOJIY3MnHpH-

QeCKaX

TeOpnX

nOrpaHnQHOrO

CJIOX JI.

npaH).{TJIX.

B OCHOBe

TeopHn

rn).{po,n:nHaMHQeCKOrO

rrOrpaHnQHoro

CJIOX

JIe)l(nT

Ipn3nQeCKH

OQeHb

npOCToe

n

nOHXTHoe

nOJIO)l(eHne,

3aKJIIO-

QaIOIlJ,eeCX B

TOM,

QTO,

KaK

CJIe).{yeT

n3

4>0PMYJIbI

HbIOTOHa

).{JIX

BX3KO-

ro

rpeHMx

(2)

100

dw

't=1l-

dy

)l,OCTaTOQHO

60JIhlllMe

3HaQeHlUI

KaCaTeJIhHhlX

HanpjI)I{eHHH

(H

CHJI

BHYTPeHHero

TpeHlUl)

MOrYT

B03HHKaTh

JIHllih

npH

HaJIHqHH

)l,OCTa-

TOqHO

60JIhllIHX

rpa)l,HCHTOB

CKOpOCTH.

TOJIhKO

B

3TH

X

CJIyya}lX

MMC-

eT

CMhlCJI

npMHMMaTh

B

paCYCT

CMJIhl

BHYTPeHHCrO

TpeHH}I,

)l,CHCT-

dw

BylO~HC

B

PCaJIhHOH

)l{M)l,KOCTM. B

)l,pyrMx

CJIyya}lX,

KOr)l,a

dy

~

0,

)l{M)l,KOGTh

MO)l{HO

paCCMaTpMBaTl:,

KaK

HeBjl3KYIO,

H,lJ,eaJIhHYIO.

OqeBH)l,HO,

YTO

60JIhiliHe

rpa)l,MCHThl

CKOPOCTM

MoryT

B03HM-

KaTh

B

)l,ByX

CJIyyajlx.

BO-nepBhIX,

npM

)l,BM)I{eHHM

)l{M)l,KOCTM

B6JIM3H

TBep)l,OH

nOBepXHOCTH,

T.K.

Ha

nOBepXHOCTM

CKOPOCTh

paBHa

HyJIIO

(YCJIOBMjI

npMJIMnaHMjI).

BO-BTOPhIX,

B

30He

KOHTaKTa

)l,ByX

nOTOKOB

)l{M)l,KOCTM,

MMCIO~MX

CYllleCTBeHHYIO

Pa3HHlJ,y

B

CKOPOCTjlX.

B

ncp-

BOM

CJIyyae

rOBOpjlT

0

B03HHKHOBeHHM

npMCTeHOYHOrO

norpa-

HHYHOrO

CJIOjl,

BO

BTOPOM

-

CB060)l,HOrO

nOrpaHMYHOrO

CJ10Sl.

Ha

pHC.

52

nOKa3aHa

cxeMa

06pa30BaHMjI

npMCTCHOYHOrO

no-

rpaHMYHoro

CJIO}!.

Typ6yJleHTHhlH

nOTOK,

MMelO~MH

O)l,HOpO)l,HOe

no-

Jle

CKopocTeH

Wo

npM

x~O,

Ha6eraeT

Ha

nJ1aCTHHY,

HeOrpaHHqCHHYIO

B

HanpaBJleHHM

OCM

z.

TIpM

x>O

CKOPOCTh

Ha

nOBepXHOCTH

paBHa

Hy-

JlIO,

a B6J1M3H

nOBepXHOCTH

06pa3YCTC}I

CHaqana

TOHKHH

JlaMMHapHhlH

Wo

W •

.-

7"

/

Or

0

~

-

"-

K,

~

7

1----'

0

',,,,,

"

""

'"

'''1

'

, "

"I

'1//

'II

Xtep

-

PHCYHOK

52 -

npHCTeHO'lHhIH

nOrpaHH'IHhIH

CJlOH

101

norpaHHlJHblM

CnOM,

TOnll.\HHa

KOTOpOrO

bJ]

B03paCTaeT

no

Mepe

Y,L{a-

neHH~

OT

Kpa~

nnaCTHHbl,

nOCKonbKY

B03MYll.\alOll.\ee

(TOpM03~ll.\ee)

,L{eMCTBHe

nnaCTHHbI

npOHHKaeT

rny6)1(e

B

nOTOK.

B

npe,L{enax

norpa-

H"'tHOrO

cno~

HMeeT

3HalJHTenbHbIM

rpa,L{HeHT

CKopocTeM,

BHe

no-

rpaHHlJHOrO

cno~

-

HeB03MYll.\eHHbIM

O,L{HOPO,L{HbIM

nOTOK.

flo

Mepe

y,L{aneHH~

OT

Kpasr

nnaCTffHbI

B

HanpaBneHHH

OCH x H

pOCTa

b

YBenH-

lJHBaeTC~

Macca

)l(H,L{KOCTH B

norpaHHlJHOM

cnoe,

a Cne,L{OBaTenbHO,

YBenHlJHBaeTcsr

H

CHna

HHepl(HH,

H O,L{HOBpeMeHHO

YMeHbllIalOTcsr

CH-

nbI

BHyrpeHHero

TPeH~

BCne,L{CTBHe

yMeHbllIeHH~

rpa,L{HeHTa

CKOpO-

CTH.

Ha

HeKOTopOM

paCCTO~HHH

X

Kp

naMHHapHbIM

pe)l(HM

Tep~eT

yc-

TOMlJHBOCTb,

T.K.

CHnbl

HHepl(HH

HalJHHalOT

npe06na,L{aTb

Ha,L{

CHnaMH

BHYTPeHHero

TpeHHSl,

H

nO~Bn~eTcsr

T Y P 6 Y n e H T H

bI

M

nor

p a H H lJ -

HbIM

cnOM

8,

COCTO~ll.\HM

H3

,L{Byx

30H:

60nbllIaSl

lJaCTb

-

c06cTBeH-

HO

Typ6yneHTHasr

30Ha

TOnll.\HHOM

b

T

H

TOHKHM

naMHHapHbIM

no,L{-

cnoM,

TOnll.\HHOM

b

Jj

,

npHMbIKalOll(HM

K

nOBepXHOCTH.

Ha

pHc.53

nOKaJaHa

cxeMa

06pa30BaHHsr

cB060,L{HOrO

norpa-

HHlJHOrO

cno~.

,ll,o

X~o

,L{Ba

O,L{HOPO,L{HbIX

nOTOKa

WOI

H

W02

,L{BHranHCb

pa3,L{eneHHbIMH

TOHKOM

nnacTHHoii.

Kor,L{a

nnaCTHHa

3aKaHlJHBaeTC~

(x>

0),

nOTOKH

HalJHHalOT

KOHTaKTHpOBaTb,

B

pe3ynbTaTe

lJero

06pa-

3YCTC51

paCllIHp$[lOll(a~C~

30Ha.

3Ta

30Ha,

B

KOTopon

npOHCXO,L{HT

H3-

MeHeHHe

CKOPOCTH OT WOl

,L{O

W02,

HOCHT

Ha3BaHHe

cB060,L{HorO

PHCYHOK

53 -

CBo6oLVlblH

1I0rpallH'IlIblH

CJIOH

102

-

~

---

f--

~

!=~

-

----

.....,.J

--'

-rr -

~~

I-.~-

-

- - - ,

...

--

=:-

I'---.---~

I

11

ill

....

_--

PHCYHOK

54 -

Cn6HJlHlaUHB

nOTOKa

B

Tpy6e

nOrpaHHLJHOrO

CJIOH.

ECJIH

06a

nOTOKa

6hIJIH

Typ6yJIeHTHhIMH,

TO H

nOrpaHHLJHhIU

CJIOU TO)f(e 6Y.l1.eT

Typ6YJIeHTHhIM;

n03TOMY

npH

B3aHMO.l1.eUCTBHH

.l1.BYX

CB060.l1.HhIX

Typ6YJIeHTHhIX

CTpyU

OTCYTCTByeT

JIaMHHapHhIU

nO.l1.CJIOU,

T.K.

HeT

TOpM03HllJ,ero

(cTa6HJIH3HpYIOllJ,ero)

BJIHHHHH TBep.l1.hIX CTeHOK.

Ha

pHC.

54

nOKa3aHa

cxeMa

06pa30BaHHH

norpaHHLJHOrO

CJIOH

npH

.l1.BH)f(eHHH )f(H.l1.KOCTH B

TPy6e.

O.l1.HOP0.l1.HhIU

nOTOK

)f(H.l1.KOCTH

BTeKaeT

B

TPy6y

H

Ha

BXO.l1.e

HMeeT

O.l1.HHaKOBYIO

no

CeLJeHHIO

3nlOpy

CKopocTeu.

3aTeM

Ha'umaeTCH

3aTOpMa)f(HBaHHe

nOTOKa

y

nOBepxHo-

CTH,

06pa30BaHHe

norpaHHLJHOrO

CJIOH H

HCKa)f(eHHe

npOIPHJIH

CKOPO-

cTeu.

3.l1.eCh Ha6JIIO.l1.aIOTCH

TaKHe

YLJaCTKH: I

(pHC.

54),

Ha3hIBaeMhlu

BXO.l1.HhIM, B KOTOPOM HapH.l1.Y C YBeJIHLJHBalOllJ,HMcH

nOrpaHHLJHhlM

CJIOeM

cYllJ,eCTByeT

H

nOTeHIJ,HaJIhHOe

H.l1.PO

C

HeB03MYllJ,eHHhIM

nOTO-

KOM;

II

- YLJaCTOK

cTa6HJIH3aIJ,HH,

HJIH

nepecTPouKH

npOIPHIlH

CKOPO-

cTeu;

III

- YLJaCTOK

cTa6HJIH3HpOBaHHoro

.l1.BH)f(eHHH,

Ha

KOTOPOM

MO)f(eT

HMeTh

MeCTO

KaK

Typ6YJIeHTHOe,

TaK

H

IlaMHHapHoe

TeLJeHHe,

LJTO

onpe.l1.eJIHeTCH

3HaLJeHHeM

LJHCJIa PeuHOIlh.l1.Ca.

nOIlY3MnHpHLJeCKHe

TeopHH

norpaHHLJHOrO

CJIOH

n03BOIlHIOT

paCCLJHTaTh

TOIlllJ,HHY

norpaHHLJHOrO

CJIOH H

npOIPHIlh

CKopocTeu.

HanpHMep,

.l1.JIH

norpaHHLJHOrO

CJIOH

y TBep.l1.0U

nOBepxHocTH

TOIlllJ,H-

Ha

JIaMHHapHoro

CJIOH

()

3aBHCHT

OT

paccToHHHH

OT KpaSi

nIlaCTHHhI

x

(pHC.

52) H

paCCLJHThIBaeTcH

no

IPOpMyJIe

8 4,64

x Re

O

.

5

'

x

(131)

a

npOIPHIlh

CKopocTeu

B

CIloe

(pHC.

55)

onHChIBaeTCH

ypaBHeHHeM:

\03

1

y

"6

o

WIWo

:0

=~f-±(fr

(132)

TOJIIlJ,MHa

Typ6YJIeHTHOro

norpa-

HM4Horo

CJI051

onMCbIBaeTC5I

ypaBHe-

HMeM

8 0,376

x

Re

O

.

2

'

(133)

a

npoqmJIb

CKopocTeH

BbI4HCJI5IeTC5I

no

<j>opMyJIe

PHCYIIOK

55 -

UpOcJ»HJIh

CKopocTeii

B

norpaHU'IHOM

CJIoe

(134)

B

BbIpa)((eHM5IX

(131) M (133) 4MCJIO PeHHOJIb.ll.Ca onpe.ll.eJI5IeTC5I

no

<j>opMyJIe:

R

WoX

e=--.

V

9.3. A3poouHaMuKa c606o0HOU 3amonneHHou myp6yneHm-

Houcmpyu

CBo6o.ll.HaJl

3aTOIIJICHHa51

Typ6YJICHTHaJl

CTPYJl -

npoToTMn

<j>a-

KeJIa

-

naM60JIec

4aCTO

BCTpe4aeTC5I

B

npOMTenJI03IIepreTM4ecKMx

yc-

TaHOBKax.

CTPY51

Ha3bIBaeTC5I

CBo6o.ll.HOH,

eCJIM

OHa

He

orpaHM4eHa

KaKMMM-JIM60

nOBepXHOCT5IMM,

M

3aTOIIJIeHHOH,

eCJIM

BhITeKaeT

B

cpe-

.ll.Y C

TaKOH

)((e nJIOTHOCTbIO.

06pa30BaHMe

CBo60.ll.HOH CTPYM

o6y-

CJIOBJIeHO

(pMC.

56)

TeM,

4TO

B

nOTOKe

no.ll. .ll.eHCTBMeM

nonepe4HbIx

Typ6YJIeHTHbIX

n y

JI

h

caL(

M H

He60JIhUIMe

06'beMhI

)((M.ll.KOCTM

BhI-

6pachIBaIOTc5I

3a

nepBOHa4aJIhHYIO

rpaHML(Y

nOTOKa.

CTaJIKMBa5lCh

C

oKpY)f(aIOIlJ,eH

cnoKoHHoH

)f(M.ll.KOCThIO 3TM

06'beMbI

BOBJIeKaIOT

ee

B

.ll.BM)f(eHMe, a MX CKOPOCTb

YMeHbUIaeTc5I.

B

pe3YJIhTaTe

3TOro

npo-

L(eCca,

Ha3blBaeMOro

T y P 6 y JI e H T H

hI

M n e p e M e

UI

MBa

H

M-

e

M,

o6pa3yeTcJI

CBo60.ll.HhIH

norpaHM4HhIH

CJIOH, pa3.ll.eJI5IIOIlJ,MH

He-

nO.ll.BM)I<HYIO

cpe.n:y

M

51.n:po

nOTOKa,

KOTopoe

COXpaH5ICT

Ha4aJIhHYIO

CKOPOCTh.

no

Mepe

Y.ll.aJIeHMJI OT

Ha4aJIa

CTpyM

TOllIlJ,MHa

51)..\pa

nOTOKa

YMeHhUIaeTC5I,

a TOJIIlJ,MHa

norpaHM4Horo

CJI051

YBeJIM4MBaeTC5I.

Pac-

CT05lHHe

OT

ConJIa

£

H,

Ha

KOTOPOM CYIlJ,eCTByeT

51)..\pO

nOTOKa,

T.e.

Ha

OCM

CTpyM

COXpaH5IeTC5I Ha4aJIhHa51 CKOPOCTh

Wo,

Ha3bIBaCTC5I

Ha-

104

qarthHhIM

yqaCTKOM.

3a

HaqarthHhIM

yqaCTKOM

CJIe,lJ,yeT

OCHOBHOH,

Ha

KOTOPOM

nOrpaHHqHhIH

CJIOH

3anOJIHlleT

BCe

nOnepeqHOe

CeqeHHe

CTPYH,

a

CKOPOCTh

Ha

OCH

MeHhllle

HaqarthHOH

(Wm

< wo).

HapY)f(HOH

rpaHHI~eH

CTPYH

Ha3hIBaIOT

nOBepXHOCTh,

Ha

KOTOPOH

CKOPOCTh

paB-

Ha

HYJIIO.

B

TeXHHqeCKHX

paCqeTaX

MO)l(HO

npHHHMaTh,

'ITO

rpaHH~hI

CTPYH

npllMOJIHHeHHhI,

CJIe,lJ,OBaTeJIhHO,

CTpyll

npe,lJ,CTaBJIlleT

C060H

paCXO,LIllIQHHCll

KOHYC

C

BeplllHHOH

C, HaXO,lJ,llIQeHCll

CJIeBa

OT

ConJIa

Ha

paCCTOllHHH

foOT

ero

cpe3a,

H

Ha3hIBaeMoH

nOJIIOCOM

CTPYH

(pHc.56).

YroJI

pacKphITHll

CB060,lJ,HOH

CTPYH

a=18

...

26°.

BHYTPH

CTPYH

MO)l(HO

BhI,lJ,eJIHTh ll,lJ,pO

nOCTOllHHOH

MaCChI

B BH,lJ,e

BHYTPeHHe-

ro

KOHyca

C

OqeHh

MarthIM

yrJIOM

paCKphITHll

<p=2,8,).

B

COOTBeTCTBHH

C

MexaHH3MOM

06pa30BaHHll

CTPYH

KOJIHqeCTBO

,lJ,BH)I(eHHll B

ee

nOnepeqHhIX

CeqeHHllX

OCTaeTCll

nOCTOllHHhIM,

KaK

3TO

nOKa3aHO

Ha

pHc.56,6.

MHoroLJHCJIeHHhIMH

OnhITaMH

YCTaHOBJIe-

9r----------=---

a

t

~==F*t=~~~~3+~~

____

x

w

..

6

L-------------------

______

t

a -

cxeMa

CTpyli,

6 -

xapaKTepliCTIiKIi

cTPYH

PHCYHOK

56 -

A3pO)~HllaMHKa

CBo6o)~llOii

CTPYH

HO,

LJTO

,lJ,aBJIeHlfe B CB060,lJ,HOH

cTpye

paBHo

,lJ,aBJIeHlflO

oKpY)l(alOIQeH

Cpe,lJ,hI.

no

,lJ,JII1He

CTpyl1

B03paCTaeT

MaccoBhlH

pacxo,lJ,

m,

na,lJ,aeT

Cpe,lJ,HHll

no

CeLJeHHIO

CKOPOCTh

W H

KHHeTHLJeCKall

3Hepfl111

CTPYH

E.

105

XapaKTepHCTHKH

CB060)J,HhlX

3aTOI1J1eHHhlX

Typ6YJIeHTHhIX

CTPYH

paCCqHThIBaIOTC}(

no

$OpMYJIaM

r. H.

A6paMOBHqa:

-

)J,JI}(

)J,JIHHhl

HaqaJIhHOrO

yqacTKa

~=44

do

"

-

)J,JI}(

CKOPOCTH

Ha

OCH

CTpyH

B

OCHOBHOM

yqaCTKe

(pHC.

56)

wm

::::0.9JO'152~+0'29)-I,

WO

~

do

-

)J,JUI

)J,HaMeTpa

CTpyH

d x

-=0517-+1

do ' do '

-

)J,JI}(

pacxo)J,a

qepe3

nOnepeqHOe

CeqeHHe

rn

=2'IJO'152~+0'29}

rno

~

do

-

)J,JI}(

CKOPOCTH

Ha

paCCTO}(HHH

y OT OCH

WWm

{-(dJ

(135)

(136)

(137)

(138)

(139)

3KcncpHMeHTaJIhHO

onhlTaMH

YCTaHOBJICHO,

qTO

pacnpe)J,eJIe-

HHC

CKOPOCTH BO

Bcex

cB060)J,Hh1X

3aTOnJIeHHhlX

CTPYHX

nO)J,06Ho,

qTO

CJIe)J,yeT

H3

npHBe)J,eHHhIX

$OPMYJI.

ECJIH

Ha

rpa$HK

HaHeCTH

3a-

BHCHMOCTh

OTHOCHTeJIhHOH

CKOPOCTH

OT

OTHOCHTCJIhHOH

Koop)J,HHa-

ThI,

TO

nOJIyqaTC}(

KpHBhIe

)J,eHCTBHTeJIhHhIe

)J,JIX

Bcex

CTPYH

He3aBH-

CHMO

01'

3HaqeHHH

BeJIHqHH

do

H

Woo

H3MeHeHHe

HeKOTophlX

xapaKTe-

PHCTHK

no

)J,JIHHe

CTPYH

B

rpa<imqeCKOM

BH)J,e

npe)J,CTaBJIeHO

Ha

pHC.

56

6 ;

Ha

pHC.

56

a

CXeMaTHqHO

nOKa3aHhI

npO$HJIH

CKOPOCTH B

pa3-

JIHqHhIX

CeqeHHXX

CTPYH.

3HepreTHqeCKHH

6aJIaHC

cB060)J,HOH

CTpyH,

pacnpOCTPaHXIO-

IlJ,eHCH B

cnoKoHHoH

cpc)J,e,

MO)J(CT

6hITh

3anHcaH

B CJIC)J,YIOIlJ,eM BH)J,C:

mow6

={m

+m,)W

r

+m

(WO-Wl~

+m,wr (140)

2 0 2 0 2

2'

r)J,e

mo

-

HaqaJIhHaH

Macca

CTpyH,

rn'

-

Macca,

npHcoe)J,HHeHHax

Ha

paccToHHHH

OT

cpc3a

co-

nJIa

)J,O

CeqCHHH

1-1,

106

WI

-

cpe,nmm

CKOPOCTh B

CeLJemiH

1-1.

B JIeBOH LJaCTlI

ypaBHeHillI

:meprenlLJeCKOrO

6aJIaHCa

3anHcaHa

KHHe-

niLJeCKaii

:meprHSI

nOTOKa

Ha

BbIxo,ne

H3

conJIa.

TIepBoe

CJIaraeMOe

npaBoH

LJaCTH

ypaBHeHHii

npe,ncTaBJUleT

C060H

KHHeTHLJecKYIO

:mep-

rHIO

CTpyH

B

CeqeHHH

1-1;

BTopoe

-

3aTpaThI

:meprHH

«Ha

y,nap»,

HJIH

Ha

3aTOpMa:>KHBaHHe HaLJaJIhHOH

MaCChI;

TpeThe

-

3aTpaTbI

3Hep-

rHH

Ha

BOBJIeqeHHe

B ,nBH:>KeHHe

npHcoe,nHHeHHOH

MaCChI.

9.4. CmpYR, smeKalOucaR s nonocmb. CmpyuHblU

annapam

ECJIH

cBo6o,nHYIO

CTPYIO

OrpaHHLJHTh

co

Bcex

CTOPOH

Ha

HeKO-

TOPOM

paccToRHHH

OT

conJIa

(pHC.

57), TO

nOBepXHOCTb

CTpyH,

YB-

JIeKalOllJ,aR OKpY:>KalOllJ,YIO

cpe,ny,

COKpallJ,aeTCiI,

HepaCTpaqeHHaSI

3HeprHR

pacxo,nyeTcSI

Ha

cOBepilleHHe

pa60ThI

npOTHBo,naBJIeHHSI,

a

'

..

. .

....

eo

..

•

~

......

..

"

.J.

..

•

...

---,-----

-"""""~~="~~-=::='::t'

'~"-=='

,,;"~'

~--+--

...

: -

..

:

..

0:

_0

..

:

--

..........

...

"

.....

1IImIl:IIl~-:-.

T.:

.:-:-.

,,:;

.T

..

'.

..

: ' .....

...

..

o •

..

l"'#

,

••

.

..

- .

~+m-p~~--~--~~·-·'~-~·O~:·+-.'~:~'-·-··-·~;-·-·-··-~-·---+.m=:~~-.-.~-

p.,~

p.,..

0,

•

~~

~

~h

~

PHCYHOK 57 - CTPYH, BTeKalOmaH B

OOJIOCTI

••

CxeMa

CTPYUHOro

aonapaTa

y OCHOBaHHR

CTpyH

C03,naeTCR

,naBJIeHHe

MeHblllee,

LJeM

B

nOCJIe-

,nylOllJ,HX

CeqeHHSIX.

B

pe3YJIhTaTe

C03,naIOTCR

30Hhl

nOHH:>KeHHOrO

,naBJIeHHe

B

KaMepax

npOMTenJI03HepreTHqeCKMX

YCTaHOBOK

(3:>KeK-

lJ,HSI),

qTO

B

HeKOTophIX

CJIyqaSIX MO:>KeT

npHBeCTM

K

Bpe,nHhiM

npH-

107

cocaM

XOJIO,lJ;HOrO

aTMOC<pepHOrO

B03,lJ;yxa.

B

,lJ;pyrHx

CJIY'laHX

3<p-

<peKT

3)((eKIJ,HH

HCrrOJIh3yeTcH

B

CrreIJ,HaJIhHhiX

YCTpOHCTBaX,

Ha3hI-

BaeMhIX

C T P Y H H

hI

M H a

rr rr

a

paT

a M

H.

TIpocTeHlllHH

CTpyHHhiH

arrrrapaT

COCTOHT

H3

pa60'lero

corrJIa

1 H

CMeCHTeJIH

2

(pHC.

57).

Pa60'lHH

rrOTOK,

BhIXO,lJ;H

H3

corrJIa

C

BhICOKOH

CKOPOCThlO,

06pa3yeT

CTPYIO,

KOTopaH

rrOCJIe

BCTpe'lH

co

CTeHKaMH

CMeCHTeJIH

rrepecTaeT

3aXBaThIBaTh

oKpy)((alOII.{YIO

cpe,lJ;y.

TI03TOMY

CTpyH

BO-

BJIeKaeT

B ,lJ;BH)((eHHe

cpe,lJ;y,

HaXO,lJ;HII.{YIOCH rrepe,lJ; BXO,lJ;OM B

CMeCH-

TeJIh.

TIOTOK,

BOBJIeKaeMhiH

B

CMeCHTeJIh,

Ha3hIBaeTCH

HH)((eKTH-

pyeMhIM.

B

OTJIH'lHe

OT

CB060,lJ;HOH

CTpyH

paCXO,lJ; )((H,l.(KOCTH B,l.(OJIh

CMeCHTeJIH

OCTaeTCH

rrOCTOHHHhlM.

PaC'leT

CTPYHHhiX

arrrrapaToB

rrpoH3BO,lJ;HTCH

HJIH

Ha

OCHOBe

ypaBHeHHH

HMrrYJIhCOB,

HJIH

Ha

OCHO-

Be

:mepreTH'leCKOrO

6aJIaHca.

TIoCJIe,l.(HHH

,l.(JIH

CTpYHHoro

arrrrapaTa

3arrHChIBaeTCR

CJIe,l.(YIOII.{HM

06pa30M

(0603HaQeHHR

Ha

pHc.57):

mpw~

W~M

(W

p

_WcJ2

-2-=(m

p

+m

u

)-2-+

mp

2 +

+mu

(w

u

-WCM.Y

+(mp

+

mu

}CM

-Pu)

2

Pp Pu

(141)

B

OTJIH'lHe

OT

3HepreTH'leCKOrO

6aJIaHCa

CB060,lJ;HOH

CTPYH

(140) B

npaBoH

'-faCTH

ypaBHeHml

(141)

HMeeTCR

'leTBepToe

CJlaraCMoe,

OTO-

6pa)((alOII.{ee

p a 6 0 T Y rr

pOT

H B

O,l.(

a B JI C H H

H,

KOTOPYIO

COBcpIIIaeT

CTpyH,

nCpeMeIl.{a}l

06beMhI

pa60'lcro

H

HH)((CKTHpYCMoro

rrOTOKOB

H3

rrOJIOCTH C

MeHhIIIHM

(Pw)

B rrOJIOCTh C

60JIhIIIHM

(PeM) ,lJ;aBJICHHeM.

CTpYHHhie

arrrrapaThi

IIIHPOKO

HCrrOJIh3YIOTC}I B

npOMTerrJIO-

3HeprCTHKe

B

TaKHX

YCTpOHCTBax,

KaK

CTPYHHhIC

HaCOChI,

3)((eKTOphI,

HH)((eKTOphI,

3JIeBaTOphI,

HH)((eKIJ,HOHHhIe

rOpCJIKH

H

,lJ;p.

Ba)l<HCHIIIeH

xapaKTepHCTHKOH

Bcex

3THX

YCTPOHCTB

}lBJIHeTC}I

MaCCOBM

KpaT-

HOCTh

HH)((eKIJ,HH, rrpe,lJ;CTaBJI}lIOII.{aH

C060H

OTHOIIIeHHe

MaCCOBoro

paCXO,l.(a

HH)((eKTHpYCMOH

Cpe,l.(hI K

MaCCOBOMY

paCXO,lJ;y

pa60'lcro

rro-

TOKa:

9.S.

CmPYR

80

8Cmpe'lHOM

u cnymHoM

nomOKax

Ha

rrpaKTHKe

B

rrpOMTerrJIo:mepreTH'leCKHX

YCTaHOBKax

CBO-

108

60)J,HaJI CTPYH

pa3BMBaeTCH

He

B

cnOKOUHOU

cpe)J,e,

a BO

BCTPeqHOM,

cnYTHOM

MJIM

CHOCH~eM

nOTOKax.

Ha

pMC.

58.

nOKa3aHbI

3nlOpbI

CKO-

pocTeu

B

cnYTHOM

M

BCTPeqHOM

nOTOKax,

KOTophIe

nOJIyqalOTcH

ny-

TeM

anre6paHqeCKoro

CYMMHpoBaHHH

CKOPOCTHhIX

npotPMJIeU

CTPYM

M cpe)J,bI.

B

cTPye

MoryT

HaXO)J,MTbCH

KaKMe-JIM60

npHMecM,

KOHl~eHTPa

QMH

KOTOPbIX

Co

OTJIMqaeTCH

OT

KOHQeHTPalJ,MH B

oKpy)KalO~eu

cpe)J,e

C

a

;

TeMnepaTypa

CTPYH,

To

TaK)Ke

MO)KeT

OTJIHQaThCH

OT

TeMnepaTypbl

oKpy)KalO~eu

cpe)J,bI

Ta.

B

o6~eM

cJIYQae

watwO,

ca:;ttco,

TatTo.

BbI-

paBHMBaHHe

TeMnepaTYP

H

KOHQeHTPaQHU

tPM3HQeCKM

npoHcxo)J,MT

TaK

)Ke,

KaK

M

BhlpaBHMBaHMe

CKopocTeu

- B

pe3YJIhTaTe

Typ6YJIeHT-

HOro

nepeMellIHBaHHH

(pOJIh

MOJIeKYJIHpHOH

)J,HtPtPY3HH

OTHOCHTeJIb-

HO

Mana).

TaKMM

06pa30M,

CKOPOCTHhle,

KOHQeHTPaQMoHHble

M

TeM-

nepaTypHhle

nOJIH

nO)J,06HhI,

M

n03ToMY

cnpaBe)J,JIMBO

COOTHOIIIeHMe

c-c

a

_

T-Ta

_

w-w

a

co-C

a

To-Ta

wo-w

a

(142)

r)J,e

c,

T M W -

COOTBeTCTBeHHO

KOHQeHTPaQMSI,

TeMnepaTypa

M

PUCYHOK

58 -

Pa3BUTue

CTPYU

B

cnYTHOM

(a)

U

BCTpelJHOM

(6)

nOTOKe

109

Курбатов Ю.Л., Шелудченко В.И., Кравцов В.В. Механика жидкости и газа: Учебное пособие

Подождите немного. Документ загружается.