Water Flow Rate 3B417A
1. **Problem Statement:** Calculate the water flow rate $Q_w$ through a pipe leakage of diameter 0.5 inch (12.7 mm) from a 1000-liter water tank and determine the time to empty the tank.
2. **Given Data:**
- Water tank volume = 1000 liters = 1 m³
- Pipe diameter $d = 0.5$ inch = 0.0127 m
- Water velocity coefficient $C_{wv} = 0.97$
- Gravity acceleration $g = 9.8$ m/s²
- Height of water tank $h = 1$ m
- Pipe discharge coefficient $C_{df} = 0.6014$
3. **Step 1: Calculate water velocity $V_{wp}$ in the pipe**
Using the formula:
$$V_{wp} = C_{wv} \sqrt{2gh}$$
Substitute values:
$$V_{wp} = 0.97 \times \sqrt{2 \times 9.8 \times 1} = 0.97 \times \sqrt{19.6} = 0.97 \times 4.427 = 4.2843\, m/s$$
4. **Step 2: Calculate flow area $F$ of the pipe**
$$F = \pi r^2 = \pi \left(\frac{d}{2}\right)^2 = 3.142 \times (0.0127/2)^2 = 3.142 \times 0.00635^2 = 3.142 \times 0.00004032 = 0.0001267\, m^2$$
5. **Step 3: Calculate water flow volume $V_{wf}$ from the pipe**
Using:
$$V_{wf} = C_{df} \times F \times V_{wp}$$
Substitute values:
$$V_{wf} = 0.6014 \times 0.0001267 \times 4.2843 = 0.0003275\, m^3/s$$
6. **Step 4: Convert flow rate to $m^3/h$**
$$Q_w = V_{wf} \times 3600 = 0.0003275 \times 3600 = 1.179\, m^3/h$$
7. **Step 5: Calculate time to empty the tank**
Tank volume = 1 $m^3$
Time $t$ in hours:
$$t = \frac{\text{Tank volume}}{Q_w} = \frac{1}{1.179} = 0.848\, h$$
Convert to seconds:
$$t = 0.848 \times 3600 = 3053\, seconds$$
Convert to minutes:
$$t = \frac{3053}{60} = 50.88\, minutes$$
**Note:** The original problem's flow area calculation used $F=3.142 \times 0.0127 \times 0.0127 = 0.00056064$ which is incorrect for area (should be radius squared). Using radius squared gives the correct flow area.
**Final answer:**
The water flow rate through the pipe leakage is approximately $1.179\, m^3/h$, and it will take about 50.88 minutes to empty the 1000-liter tank through the 0.5 inch pipe leakage.
This model helps detect leakage by monitoring if the flow rate exceeds a threshold, triggering a sensor alert.