Fluid Mechanics Question
Question 2. A weir is an obstruction in a channel flow which can be calibrated to measure the flowrate, see Figure 2. The volume flowrate Q varies with acceleration due to gravity g, weir width b (into the paper), and upstream water height H above the weir crest, i.e. Q = fg,b,H. Answer the following:
(a) Determine the number of parameters (n) in the problem. Write the dimensions (in terms of primary dimensions) for each of the parameters. [5 marks]
(b) List all the primary dimensions represented in the problem. [2 marks]
(c) In the problem, what is the expected number of non-dimensional parameters? [2 marks]
(d) Without choosing weir width b as a repeating parameter, generate a non-dimensional relationship between the parameters. Show all your work. [16 marks]
(e) If it is known that Q is proportional to b, obtain a unique functional relationship between the parameters. [5 marks]
Weir width b into the plane
V
H
Weir
Figure 2
(TOTAL 30 MARKS)