Unformatted text preview: 1. Given d, L, and V or Q, , , and g, compute the head loss hf (head-loss problem).
2. Given d, L, hf, , , and g, compute the velocity V or flow rate Q (flow-rate
3. Given Q, L, hf, , , and g, compute the diameter d of the pipe (sizing problem).
Only problem 1 is well suited to the Moody chart. We have to iterate to compute velocity
or diameter because both d and V are contained in the ordinate and the abscissa of the chart.
There are two alternatives to iteration for problems of type 2 and 3: (a) preparation
of a suitable new Moody-type chart (see Prob. 6.62 and 6.73); or (b) the use of solver
software, especially the Engineering Equation Solver, known as EES , which gives
the answer directly if the proper data are entered. Examples 6.9 and 6.11 include the
EES approach to these problems. Type 2 Problem:
Find the Flow Rate Even though velocity (or flow rate) appears in both the ordinate and the abscissa on
the Moody chart, iteration for turbulent flow is nevertheless quite fast, because f varies
so slowly with Red. Alternately, in the spirit of Examp...
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This note was uploaded on 10/27/2009 for the course MAE 101a taught by Professor Sakar during the Spring '08 term at UCSD.
- Spring '08