Experiment Report
Introduction
The flow duration curve is cumulative frequency curve. In the curve, the horizontal
axle represents the percentage of the exceeded time. The vertical axle
represents the discharge of the flow. It provides s a convenient way to
understand the relationship between flow level and the percentage of time when
the any specific flow level appeared.
To draw a flow duration curve requires the daily or
weekly or monthly flow data. Simple analysis and calculation of the long term
data can show a direct cognition of the flow data, including the maximum flow,
the minimum flow and the average flow. By using the formula, it is possible to
draw a flow duration.
Method
Step 1 Download the data from the OPW data base.
Step 2 List the flow data in a row, arrange the data in
time order.
Date
|
Flow Data
|
01/01/1976
|
13.305083
|
01/01/1977
|
24.273569
|
01/01/1978
|
18.71693
|
01/01/1979
|
56.884185
|
01/01/1980
|
33.356773
|
01/01/1981
|
26.84866
|
01/01/1982
|
33.299156
|
01/01/1983
|
39.337019
|
01/01/1984
|
31.927008
|
Step 3 Analyze the data to obtain the maximum flow, the
minimum flow, the average flow and the amount of the flow data units.
Maximum
|
132.545
|
Minimum
|
1.782934
|
Average
|
18.25085718
|
N
|
12406
|
Density
|
1000
|
Step 4 Determine the flow range with the maximum flow figure
and the minimum flow figure. Divide the range equally into several sections.
Flow Range
|
0
|
5
|
15
|
25
|
35
|
45
|
55
|
65
|
75
|
85
|
95
|
105
|
115
|
125
|
135
|
Step 5 Calculate the frequency of all the flow data and
compute the percentage of appearance of each range of the flow and the FDC%.
Flow Range
|
Number
|
%
|
FDC%
|
0
|
0
|
0.00
|
100.00
|
5
|
1796
|
14.48
|
85.52
|
15
|
4997
|
40.28
|
45.24
|
25
|
2688
|
21.67
|
23.58
|
35
|
1377
|
11.10
|
12.48
|
45
|
670
|
5.40
|
7.08
|
55
|
397
|
3.20
|
3.88
|
65
|
229
|
1.85
|
2.03
|
75
|
131
|
1.06
|
0.98
|
85
|
59
|
0.48
|
0.50
|
95
|
28
|
0.23
|
0.27
|
105
|
11
|
0.09
|
0.19
|
115
|
7
|
0.06
|
0.13
|
125
|
11
|
0.09
|
0.04
|
135
|
5
|
0.04
|
Step 6 With the row of the FDC% and the flow range, it is
possible to draw a FDC graph.
Result
With common knowledge that,
number of hours in year is 8760 seconds.
number of seconds in hour is 3600 seconds.
Efficiency is usually 0.8 as given.
Head difference is 5 metres as given.
Capacity installed is 40, 50 or 60 cumecs.
Water density is 1000
Gravity is usually 9.81
And the formula,
Power is equal to efficiency* density*gravity*average flow*head difference
Energy is equal to number of seconds in hour*number of
hours in year*Power*Difference of FDC% of two ranges.
There come the different energy as follow,
Capacity installed
|
40m
|
Energy totally
|
20643828.60
|
MW-hrs
|
50m
|
21519615.30
|
MW-hrs
|
||
60m
|
21999402.77
|
MW-hrs
|
Conclusion
The total energy shows a positive relationship with the
installed capacity.
--------------------------------------------------------------------------------------------------------------------------
This is the first assignment, my kind professor gave me the score of 75/100(mostly like an A to me).
Thanks for his kindness.
