# Design Storm Hyetograph Generation Spreadsheet

## Where to Find a Design Storm Hyetograph Generation Spreadsheet

To obtain a Design Storm Hyetograph Generation excel spreadsheet, click here to visit our spreadsheet store.  For use in stormwater management calculation, you can buy a convenient Design Storm Hyetograph generation excel spreadsheet for a very reasonable price?  This spreadsheet will generate a design storm hyetograph using the Chicago storm model, a triangular storm model or the “alternating blocks” procedure in either U.S. or S.I. units.  Read on for information about Excel spreadsheets that can be used for design storm hyetograph generation.

## Models for Design Storm Hyetograph Generation

Several different hyetograph models can be used for design storm hyetograph generation, including the Chicago storm, triangular, or rectangular (constant intensity design storm) models or the “alternating blocks” procedure for constructing a design storm hyetograph.  An initial step typically needed is the generation of an equation for storm intensity as a function of storm duration at the design location, for the design recurrence interval.

## The Chicago Storm Hyetograph

For example, the Chicago storm hyetograph model uses the equation at the left for the portion of the hyetograph before the peak storm intensity.  A slightly different equation is used for the portion of the design storm hyetograph that is after the peak storm intensity.  The resulting hyetograph has the general shape shown in the diagram at the right.  A user specified parameter is r, which is the fraction of the hyetograph that is before the point of peak storm intensity.  The triangular hyetograph model is similar in shape, but the lines before and after the peak storm intensity are straight instead of curved.

## Example Design Storm Hyetograph Generation Excel Spreadsheet

The Design Storm hyetograph generation excel spreadsheet partially shown in the image below can be used to generate a triangular or Chicago storm hyetograph as discussed above.  The portion shown is for generating an equation for storm intensity as a function of storm duration.  This Excel spreadsheet, as well as others for stormwater management calculations, is available in either U.S. or S.I. units for a very reasonable price in our spreadsheet store.

References

1. American Iron and Steel Institute, Modern Sewer Design, 4th Edition, 1999.

2. Bengtson, Harlan H., “Chicago Storm Hyetograph Generation Spreadsheet,”  an online informational blog article.

# Air Viscosity Temperature Calculator Spreadsheet

## Where to Find an Air Viscosity Temperature Calculator Spreadsheet

To obtain an Air Viscosity Temperature Calculator excel spreadsheet, click here to visit our spreadsheet store.  Why use online calculators or tables to find the viscosity of air at a specified pressure and temperature when you can buy a convenient air viscosity temperature calculator excel spreadsheet for only \$4.95?  This spreadsheet will calculate the viscosity of air at specified pressure and temperature in either U.S. or S.I. units.  Read on for information about Excel spreadsheets that can be used as an Air viscosity temperature calculator for specified pressure and temperature.

## Air Viscosity Temperature Calculator Spreadsheet Applications

An  Air Viscosity Temperature calculator excel spreadsheet  can be used for any situation where a value of air viscosity is needed at a specified pressure and temperature.  This could include calculations for air flow in a pipe, drag force or drag coefficient calculations for flow of an object through air, and any other calculation requiring the Reynolds number for air flow or flow through air.  For example, see the related article, Fanno Flow Excel Spreadsheet for Air Flow in a Pipe.

## Equations for an Air Viscosity Temperature Calculator Spreadsheet

Equations are available for an air viscosity temperature calculator to calculate the viscosity of air at specified temperature and pressure.  The spreadsheet shown in  the diagram below calculates air density using an equation for air viscosity as a function of temperature ratio, Tr , and density ratio, ρr  , where in U.S. units:  Tr   =  T/238.5 with T in degrees R  and ρr    =  ρ/0.6096 with ρ in slugs/ft3.  Since the air density is needed for this calculation, the spreadsheet also calculates the density of air at the specified air temperature and pressure.  The complete equations are included in the spreadsheet discussed above and shown in the screenshot below.

## Example Air Viscosity Temperature Calculator Excel Spreadsheet

The Air Viscosity Temperature calculator excel spreadsheet shown in the image below can be used to calculate the viscosity of air at given temperature and pressure as discussed above.  This Excel spreadsheet and others for fluid properties calculations, in either U.S. or S.I. units are available for very reasonable prices in our spreadsheet store.

References

1. Bengtson, Harlan H, “Air Viscosity Calculator Pressure Temperature Spreadsheet,”  An online informational blog article.