level pool routing report
Level Pool Routing Laboratory Report
CIVL4330
Hydrology and Open Channel
University of Newcastle
Results and Discussion:
Reservoir Flows:
Inflow from the tank was calculated using the known internal dimensions of the tank, the % full reading, and the time step which the data was collected.
Where tank volume is (m3), radius =0.2m, and the depth =2.873m
Where Inflow from the tank), tank volume is (m3), % Full is the percentage of initial tank volume expressed as a decimal, and change in time is measured in seconds.
The inflow into the tank was then graphed to show the Inflow vs. Time, the results obtained had some outliers in the initial negative trend so a linear interpolation of the part of the data set was instead used. The amendment via linear interpolation can be found in Appendix A, the graph is displayed below in Figure 1. Figure 1: Inflow from the tank vs. Time
Initially the flow rate increases quickly as the head in the tank is at its highest causing increased pressure, the flow then steadily decreases due to a reduction in pressure before the tank nears empty and the inflow plateaus to a lower level after 4 minutes.
In figure 2 the total energy line from the reservoir to the pipe outlet can be seen.
Figure 2: Tank Energy Grade Line
To determine the relationship between discharge and the square root of height (h) the following equations were used.
Using the two reference points in figure 2, the following expressions can be derived
Ignoring entry losses and only considering losses at the valve
Substituting in :
Taking all the known terms to one side:
Knowing that V=Q/A:
As is constant this shows that
Using Conservation of mass shows:
Change in storage () = Inflow – Outflow (Q(t))
Where inflow into the tank goes to zero and outflow changes over time.
The slope of the inflow hydrograph can be seen to decrease linearly with time from the
CIVL4330
Hydrology and Open Channel
University of Newcastle
Results and Discussion:
Reservoir Flows:
Inflow from the tank was calculated using the known internal dimensions of the tank, the % full reading, and the time step which the data was collected.
Where tank volume is (m3), radius =0.2m, and the depth =2.873m
Where Inflow from the tank), tank volume is (m3), % Full is the percentage of initial tank volume expressed as a decimal, and change in time is measured in seconds.
The inflow into the tank was then graphed to show the Inflow vs. Time, the results obtained had some outliers in the initial negative trend so a linear interpolation of the part of the data set was instead used. The amendment via linear interpolation can be found in Appendix A, the graph is displayed below in Figure 1. Figure 1: Inflow from the tank vs. Time
Initially the flow rate increases quickly as the head in the tank is at its highest causing increased pressure, the flow then steadily decreases due to a reduction in pressure before the tank nears empty and the inflow plateaus to a lower level after 4 minutes.
In figure 2 the total energy line from the reservoir to the pipe outlet can be seen.
Figure 2: Tank Energy Grade Line
To determine the relationship between discharge and the square root of height (h) the following equations were used.
Using the two reference points in figure 2, the following expressions can be derived
Ignoring entry losses and only considering losses at the valve
Substituting in :
Taking all the known terms to one side:
Knowing that V=Q/A:
As is constant this shows that
Using Conservation of mass shows:
Change in storage () = Inflow – Outflow (Q(t))
Where inflow into the tank goes to zero and outflow changes over time.
The slope of the inflow hydrograph can be seen to decrease linearly with time from the
References: Kuczera, G. (2007), CIVL4330 Hydrology Volume 2-Open Channel Hydraulics, University of Newcastle. Manning, S