Successful fluid flow problem-solving is all about the application and understanding of fluid properties such as viscosity, density, compressibility, surface tension and vapor pressure. Many problems relate to pressure drop of flow in pipes and pumping.
Professor Fred Stern defines and explains fluid properties in chapter two of his lecture notes from a fluid mechanics course at the University of Iowa. A portable document format (PDF) file defines and explains each fluid property. A free Acrobat Reader for PDF files is available for download from Adobe. Another application, Acrobat speedup, makes the Acrobat Reader load much faster.
The Mechanics of Fluids and Transport Processes course site includes a 41-slide PowerPoint presentation, "Introduction to Fluid Mechanics," that provides an excellent visual preview of the entire field. It is worth viewing in its entirety if you are interested in the expansive influence of fluid mechanics. Coverage includes descriptions of analytical, experimental and computational fluid dynamics. You can download a free PowerPoint viewer from Microsoft.
Pressure drop calculations have always been important, but are time consuming when working with fluid flow problems. A pressure drop calculator program can conveniently and quickly perform and document the calculations, as well as provide Reynolds Number, fluid velocity, average residence time, equivalent length and total pressure drop based upon user inputs. A link to formulae provides the basis for laminar and turbulent flow pressure-drop calculations. Additional links are provided to tables with equivalent length of valves and fittings and surface roughness of various materials. I referenced an online Macromedia Flash version of the calculator in my December 2003 column. Downloads linked from the latter site include a stand-alone pressure drop calculator, a virtual reality program to visualize 3D fluid flow, an economic pipe-sizer and flange data software. Of course, there are commercially available software packages for pressure drop calculations, many of which can be found in a Web search (click here).
"Rethinking the Pump Selection Process," an article by Dave Brockway and Trygve Dahl that appeared in Chemical Processing in February 2002, states that the complexities of pumps used in chemical processing plants are giving pump manufacturers an opportunity to provide capable Internet-based selection and configuration tools. Pumping is now most often represented on the Internet by Web sites from pump manufacturers and by portals linking to suppliers and distributors.
One such portal is Pump World, which is dedicated to being the premier portal for the pump industry on the Web. The site includes tutorials for centrifugal and positive displacement pumps, as well as troubleshooting. There also are manufacturer and distributor links for pumps and mechanical seals, as well as a forum that is available for interactive communication.
Another portal is Pump Manufacturers, which contains information about pump types, suppliers, manufacturers and related topics. A reciprocal links page includes a variety of industrial and educational sites. A link to free flow calculators and calculation software includes venturi tube, turbulent flow, pipe flow rate, Prandtl probe and Reynolds Number calculators. Several of these calculators are located at Netfirms.
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By Alan E. Hodel, Internet columnist