QvertPipeUSBR: Discharge from a Vertical Pipe by U.S. Bureau of Reclamation

In wasquith-usgs/vertPipeFlow: Discharge from a Vertical Pipe

Description

This function solve equations for circular-weir and jet flow issuing from a vertical pipe. For conditions of quasi-jet flow an interpolation into a table derived from a graphical image of discharge curves is used. The height of water above the pipe is defined as h, and the internal diameter of the pipe is defined as d. If h < 0.37d then the pipe is flowing as a circular weir and Q = 6.17d^{1.25}h^{1.35}. If h > 1.4d then the pipe is flowing as a jet and Q = 5.01d^{1.99}h^{0.53}. Otherwise the pipe is flowing as a quasi-jet and explicit equations are not available, but are derived from figure 14-12 in USBR (2001) that is attributed to Stock (1955). Bos (1989) reports that the jet equation has an accuracy of \pm 10 and the weir equation has an accuracy of \pm 15.

Usage

QvertPipeUSBR(h=NULL, d=NULL, digits=3,
              hunits=c("inch", "feet"),
              dunits=c("inch", "feet"),
              Qunits=c("gpm",  "cfs"),
              forceTable=FALSE)

Arguments

h	A scalar value for the height of water above the pipe,
d	A scalar value for the internal diameter of the pipe,
digits	The number of digits to round the discharge result,
hunits	The units on the h,
dunits	The units on the d,
Qunits	The units on the discharge, and
forceTable	A logical controlling whether the quasi-jet table is used instead of equations.

Value

A list of results including the discharge.

Author(s)

W.H. Asquith

References

Bos, M.G., 1989, Discharge Measurement Structures, ILRI Publication 20, Third Revised Edition, Wageningen, The Netherlands.

Stock, E.M., 1955, Measuring of Irrigation Water, Bulletin No. 5, Utah State Engineering Experiment Station and Utah Cooperative Extension Service.

United States Bureau of Reclamation, 2001, Water Measurement Manual—A water resources technical publication: United States Department of the Interior Bureau of Reclamation, www.usbr.gov/pmts/hydraulics_lab/pubs/wmm/chap14_13.html

Examples

str(QvertPipeUSBR(h=.15, d=8))
str(QvertPipeUSBR(h=3,   d=8))
str(QvertPipeUSBR(h=15,  d=8))

replicate(10,
            QvertPipeUSBR(h=runif(1, min=1.5, max=60),
                          d=runif(1, min=2,   max=12)));

H <- seq(.01,100,by=0.1)
Q <- sapply(H, function(x) {
  	        return(QvertPipeUSBR(h=x,d=8)$Q) } )
plot(H,Q, type="l")

wasquith-usgs/vertPipeFlow documentation built on May 30, 2019, 4:11 p.m.