Lusk_Pipe Storage.mcdx
- November 26, 2013
- 4 replies
- 2540 views
UPDATE 2014-01-15: The attached .zip file now contains a Mathcad Prime 3.0 worksheet (.mcdx) and—for those of you who are still using earlier verisions of Mathcad—an Adobe Acrobat printout (.pdf) of the worksheet so can see how it is put together.
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The working volume in a sewer or storm drainage wetwell can sometimes be augmented by including the volume of water stored in the inlet pipe(s). Pipe storage is only possible when the design HWL (High Water Level) in the wetwell is higher than the invert of the inlet pipe (see diagrams). The purpose of this worksheet is to calculate the available storage volume in one inlet pipe. This worksheet does not consider hydraulic factors that can affect the use of pipe storage. Wetwell volume requirements are covered in a separate worksheet (Lusk_Wetwell Sizing and Pump Cycling.mcdx). Because the pipe cross-section is assumed to be both circular and vertical, accuracy suffers if the pipe slope is too great. However, most sewers and storm drains are flat enough to ignore this caveat.
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I recently made a quantum leap from the 15-year-old MC 8.0 Standard to MC Prime 3.0. This worksheet is by far the most elaborate one I have yet developed in MC Prime 3.0. It is also the first one I have uploaded so far that did not have a MC 8.0 Standard predecessor. I never attempted to use MC 8.0 Standard to implement this calculation because it lacks programming. The calculation could have been done with dozens of IF statements, but programming is so much more elegant and manageable. However, this worksheet does have a Microsoft Excel predecessor. The Excel spreadsheet uses the Average End Area method to calculate volumes instead of the combination of simple equations and complex integrals used in this worksheet. By using different methods, each version is a useful cross-check of the other. The results differ in the decimal places, but that is to be expected here because the Average End Area is an approximation.
Except for a couple of trival practice programs, this worksheet contains my first two real programs. Both are fairly elaborate (for me at least), although they pale in comparison to the awesome program I saw in the Soduku solver in the Puzzles and Games Section. I also got to use a little calculus and symbolic algebra for the first time in several years.
Enjoy.