Uploaded by Arkan F. Said

4020H089 強制對流

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Introduction
Figure 1 The Free and Forced Convection Apparatus (TD1005)
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User Guide
TD1005 Free and Forced Convection
Experiment 4: Forced Convection - Fixed Power
Introduction
Aims
Procedure
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39
User Guide
TD1005 Free and Forced Convection
Table 3 Blank Results Table
Results Analysis
User Guide
38
TecQuipment Ltd
TD1005 Free and Forced Convection
Experiment 4: Forced Convection - Fixed Power
-1
Forced Convection at 2 m.s
Maximum Temperature Difference at 15 W Input Power
50
45
40
Ts-Tin (°C)
35
30
25
20
15
10
5
0
Flat
Finned
Pinned
Surfaces
Figure 28 Typical Results
Experiment 5: Forced Convection - Flow Obstruction
Table 10 Typical Results
User Guide
60
TecQuipment Ltd
TD1005 Free and Forced Convection
Horizontal and Vertical Finned Surfaces
Figure 20 Vertical, Flat and Horizontal Finned Surface
Heat Transfer Coefficient (Convective) (hc)
·
Q
h c = -----------------As Tm
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User Guide
TD1005 Free and Forced Convection
·
Q
Tm
T OUT – T IN
T m = ------------------------------T S – T IN
log ----------------------T S – T OUT
Nusselt Number (Nu)
hc L
Nu = ------------k air
L
User Guide
24
TecQuipment Ltd
TD1005 Free and Forced Convection
Heat Transfer Surfaces
Noise Levels
User Guide
10
TecQuipment Ltd
TD1005 Free and Forced Convection
Free Convection
Forced Convection
Thermal Conductivity of Air (kair)
k
Thermal Conductivity of Air
0.032
Thermal Conductivity (W/mK)
0.031
0.03
0.029
0.028
0.027
0.026
0.025
0.024
0
20
40
60
80
100
Temperature (°C)
Figure 16 Thermal Conductivity of Air
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User Guide
Flat
T2-T1
Pinned
45
11.5
Forced Convection at 2m/s Maximum
Temperature Difference at15 W lnput Power
50
45
40
35
30
25
20
15
10
5
0
Flat
Pinned
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