流体力学泵与风机_课后题答案详解

流体力学泵与风机部分习题答案 2-15

解：（1）当1γ为空气 21p p = ()A B p h z p =++γ ()h z p p p B A +=-=∆γ 3.010008.9⨯⨯= kpa pa 94.22940== （2）当1γ为油 31p p =

()z H h p p A +++=γ1 ()H h p p B γγ++=13

H h z H h p p p p p B A γγγγγ--+++-=-=∆131

h z h 1γγγ-+=

1.09000

2.010008.91.010008.9⨯-⨯⨯+⨯⨯= kpa pa 04.22040== 2-16 解：21p p =

()211h h H p p M +++=水γ 212h h p p a 汞油γγ++=

()2121h h p h h H p a M 汞油水γγγ++=+++

()2.010008.96.1378502.05.110008.998011⨯⨯⨯+⨯=++⨯⨯+-h h 26656785098002.098005.1980098011+=+⨯+⨯+-h h 1960147009802665619501--+=h

m h 63.51= 2-28

解：()21h h p -=γ

()()()b h h h b h h h h P 022

10212145sin 45sin 21

-+--=γγ ()()145

sin 22310008.9145sin 232310008.9210

0⨯-⨯⨯+⨯-⨯-⨯⨯⨯= kN N 65.343465022

5

10008.9==⨯⨯=

()()()P

bl h h h bl h h h h l D D D 2022110212145sin 45sin 21

-+--=

γγ m 45.22

2

5

10008.92

22210008.9232

2210008.9=⨯⨯⨯⨯⨯+⨯⨯⨯=

2-32 解：b h h b h h P 0

2

2

021

45sin 2145sin γγ+= 22

2

2

210008.9212222110008.9⨯⨯⨯⨯⨯+⨯⨯

⨯⨯=

kN N 8576.1106.1108572810008.9==⨯⨯=

P

h h b h h h h b h h l D 02102202102145sin 3245sin 2145sin 245sin ⎪⎭⎫ ⎝⎛

++⎪⎭⎫ ⎝⎛+=

γγ 2

810008.92

37

2410008.9222410008.9⨯⨯⨯⨯⨯+⨯⨯⨯=

2613= 26

722613=-=p l

T P G l T l P l G ⨯=⨯+⨯

226

7

2810008.9162.19⨯=⨯⨯⨯+⨯T kN T 31.1013

4

.27481.9=+

= 2-41

解：245sin 0

=⨯=r h

b h h P x ⨯⨯

⋅⋅=2

1γ 42

12210008.9⨯⨯

⨯⨯⨯=

kN N 2.3939200==

V P z γ=

b r r r

⎪⎭

⎫

⎝

⎛⨯⨯⨯-=002

45cos 45sin 2136045πγ 4212281214.310008.92

⨯⎪⎭

⎫ ⎝

⎛

⨯⨯-⨯⨯⨯⨯= kN N 344.2222344==

kN P 1.45344.222.3922=+=

03057.0arctan 2

.39344.22arctan arctan

≈===x z P P α

3-3

解：（1）s m v d Q /0049.010025.04

4

32323=⋅⋅=

⋅=

π

π

s kg Q /9.4=ρ

（2）s m v d d v /625.032

131=⎪⎪⎭⎫

⎝⎛= s m v d d v /5.232

232=⎪⎪⎭

⎫ ⎝⎛=

3-5

解：s m h m Q /778.2/100003

3

==

s m d Q

v /204

2

≤=

π

所以，177.04=≥

π

v Q

d 所以，mm m d 45045.0== 此时，s m d Q d Q

v /4.1763585

.0112

.1144

2

2

===

=

ππ

3-6

解：225432120

5

4

d d A A A A A π

π

=

=====

221140

12021d d A A ππ=⋅="=' 222240

12021d d A A ππ=⋅="='

223340

12021d d A A ππ=⋅="='

224440

12021d d A A ππ=⋅="='

225540

12021d d A A ππ=⋅="='

221401

4

d d ππ

=

d d 1011=

d r 10

211= 22

24034

d d ππ

=

d d 1032= d r 1023

2= 2234054

d d ππ

=

d d 1053= d r 10253= 22

44074

d d ππ

=

d d 1074= d r 10

274=