Coursework - Thermofluids
A water tank empties by gravity into another tank via an inclined pipe, as shown in Fig. 1 below. Both tanks are open to the atmosphere and the difference in levels is h. Since the tanks are large, h can be assumed to be constant.
Using the individual data assigned to you, calculate:
1. Secondary loss coefficients kL2 and kL3.
2. The length of the small diameter pipe, in meters.
3. The volumetric flow rate Q through the connecting pipes, in m3/s.
4. The water velocity in each pipe (V1, V2) and hence the corresponding Reynolds numbers (Re1,Re2).
5. The individual primary and secondary head losses, in meters (hf1, hf2, hL1 to hL4).
Fig. 1 Water tank system
Note that both bends have the same centreline radius (r = 300 mm) and both horizontal sections of the pipe of diameter d1 have the same length. You have been assigned a value of the secondary loss coefficient associated with the entry to the smaller pipe (kL1). However, you are required to calculate the loss coefficients for the bends (kL2) and the sudden expansion (kL3), using the data assigned to you. The loss coefficient associated with entry to the second reservoir (kL4) is 1. You will also be assigned values for the friction factor for each pipe, f1 and f2. Assume that the dynamic viscosity and density of water are 1.002×10-3 Pa.s and 998 kg/m3, respectively.
Notes:
- You are assigned the following data: h, d1, d2, L1, L2 (all in metres); θ (degrees); loss coefficients kL1, f1, f2.
- When you estimate the length of the small diameter pipe, you may ignore the effect of the bend radius (i.e. assume it is made of three straight sections). Radius r is given only to enable you to estimate the loss coefficient associated with the bends, using Fig. 2.
- This assignment contributes 25% to the overall module mark.
The loss coefficients associated with the pipe bends can be estimated from the graph shown in Fig. 2:
Fig. 2: Pipe bend loss coefficient
Submission requirements:
- Submit your report on Canvas in PDF format, on or before the deadline.
- The FIRST PAGE should be a summary table, in the format shown below. Enter your answers in the spaces provided.
- Subsequent pages will be your hand-written calculations. Keep them as neat as you can, as marks will be deducted for work that is illegible.