1.光滑管阻力系数实验
以编号2的数据为例,计算如下:
QQu==
A⨯d24
0.01m3/s÷3600s/h==0.0553m/s
2
⨯(0.008m)
4
Re=
d⋅u⋅ρ
μ
8⨯10-3⨯0.0553⨯998.2
==439.4066
-3
1.005⨯10
2⋅d⋅Pf2⨯8⨯10⨯0.0490⨯10λ===0.151722
ρ⋅l⋅u998.2⨯1.695⨯0.0553
-33
2.粗糙管阻力系数实验
以编号1的数据为例,计算如下:
u=
=
QQ=A⨯d24
0.102m3/s÷3600s/h
4
=0.3608m/s
2
⨯(0.010m)
Re=
d⋅u⋅ρ
μ
10⨯10-3⨯0.3608⨯998.2==3619.1295
-3
1.005⨯10
2⋅d⋅Pf2⨯10⨯10⨯5.3⨯10λ===0.581422
ρ⋅l⋅u998.2⨯1.695⨯0.3608
-33
3.局部阻力系数实验
以编号1的数据为例,计算如下:
QQu==
A⨯d24
0.02m3/s÷3600s/h==0.0177m/s
2
⨯(0.02m)4
Pf=2P2-P1
=2⨯0.2060-02452=0.2845kpa
⎛2⎫Pf⎛2⎫0.2845ξ= ρ⎪⎪⨯u2= 998.2⎪⨯0.01772=1.8225
⎝⎭⎝⎭
以编号1计算举例:
u入=
=
=A⨯d24
12.02m3/s÷3600s/h
4
=3.28m/s
2
⨯(0.036m)
u出=
=
QQ=A⨯d24
12.02m3/s÷3600s/h
4
=2.41m/s
2
⨯(0.042m)
H=Z出-Z入
22
u-uP-P入出1
+2+
ρg2g
51.5+6.62.412-3.282
=0.25++=5.93m
998.2⨯9.812⨯9.81
N=功率表读数⨯电机效率=0.77kw⨯60%=462.00w Ne=HQρg=5.93⨯12.02÷3600⨯998.2⨯9.81=193.90w
Ne193.90
η=⨯100%=⨯100%=41.97%
N452.00
泵的特性曲线
1.光滑管阻力系数实验
以编号2的数据为例,计算如下:
QQu==
A⨯d24
0.01m3/s÷3600s/h==0.0553m/s
2
⨯(0.008m)
4
Re=
d⋅u⋅ρ
μ
8⨯10-3⨯0.0553⨯998.2
==439.4066
-3
1.005⨯10
2⋅d⋅Pf2⨯8⨯10⨯0.0490⨯10λ===0.151722
ρ⋅l⋅u998.2⨯1.695⨯0.0553
-33
2.粗糙管阻力系数实验
以编号1的数据为例,计算如下:
u=
=
QQ=A⨯d24
0.102m3/s÷3600s/h
4
=0.3608m/s
2
⨯(0.010m)
Re=
d⋅u⋅ρ
μ
10⨯10-3⨯0.3608⨯998.2==3619.1295
-3
1.005⨯10
2⋅d⋅Pf2⨯10⨯10⨯5.3⨯10λ===0.581422
ρ⋅l⋅u998.2⨯1.695⨯0.3608
-33
3.局部阻力系数实验
以编号1的数据为例,计算如下:
QQu==
A⨯d24
0.02m3/s÷3600s/h==0.0177m/s
2
⨯(0.02m)4
Pf=2P2-P1
=2⨯0.2060-02452=0.2845kpa
⎛2⎫Pf⎛2⎫0.2845ξ= ρ⎪⎪⨯u2= 998.2⎪⨯0.01772=1.8225
⎝⎭⎝⎭
以编号1计算举例:
u入=
=
=A⨯d24
12.02m3/s÷3600s/h
4
=3.28m/s
2
⨯(0.036m)
u出=
=
QQ=A⨯d24
12.02m3/s÷3600s/h
4
=2.41m/s
2
⨯(0.042m)
H=Z出-Z入
22
u-uP-P入出1
+2+
ρg2g
51.5+6.62.412-3.282
=0.25++=5.93m
998.2⨯9.812⨯9.81
N=功率表读数⨯电机效率=0.77kw⨯60%=462.00w Ne=HQρg=5.93⨯12.02÷3600⨯998.2⨯9.81=193.90w
Ne193.90
η=⨯100%=⨯100%=41.97%
N452.00
泵的特性曲线