Unsteady water depth measurement in a partially filled 7.6 cm diameter horizontal pipe

Abstract

A research program to investigate the wastewater solid transport in pitched horizontal drains is under way. The objective of the program is to develop data base and establish correlations for selecting drain pipe diameter, length, and slope for effective solid waste transport with reduced water usage.The purposes of this portion of the research program were:(1) to measure the stream depth histories of unsteady, nonuniform, partially filled pipe flow that ensues when water from a plumbing fixture is discharged into the drain; and (2) to examine the effects of the presence of a cylindrical solids and other relevant variables on the stream depth. The variables selected for the study include:the water volume discharged from the fixture into the drain; the drain slope, and the diameter and length of cylindrical solids.This report contains a description of the experimental apparatus, instrumentation and procedures; and a summary of the stream depth data acquired from experiments in a 7.6 cm diameter drain.The depth of water stream at any given cross-section of the drain rises rapidly to a peak value and then gradually falls to zero. The peak value of stream depth at a pipe cross-section decreases as the distance from the drain entrance increases. At a given pipe cross-section the peak value of stream depth increases with an increase in the water volume used, a decrease in the pipe slope, and with the presence of a solid in the drain. The variations in the diameter of the solid influence the stream depth history more than the variation in its length.iii PREFACE This report is one of a group documenting National Bureau of Standards (NBS) ressearch and analysis efforts in development of water conservation test methods, models for technical and economic analysis, and strategies for implementation and acceptance of practices.

Experimental investigation of transport of discrete solids with surge flows in a 10.0 CM-diameter partially filled pipe

“…Observations of the surge flow and solid transport phenomenon revealed information identical to that observed previously during the earlier experimental work [9,10]. A summary of the observations is presented below.…”

“…and X = h/D (10) During a surge flow the instantaneous water velocity will be maximum when ((((X^-) is maximum, and will be maximum when the quantity [f(Xj_) (|)"''^(Xt)] is maxmum, For flow through circular pipes, t|)(X) initially increases as X is increased, attains the maximum value when X is about 0.81, and then starts to decrease as X is further increased. The quantity [f(X) (()^'^(X)] follows a trend similar to that for <j)(X), however, it attains the maximum value when X is about 0.94.…”

“…Effects of the experimental variables (i.e., water volume used, size of the solid, and the pipe slope) on the velocity attained by the solid are similar to those indicated by the data of earlier experiments conducted in a 7.6-cm. diameter pipe [9,10]. A discussion of these effects is presented below.…”

“…Data acquired earlier, during the exploratory experiments in a 76-ram (3 in) diameter pipe has been presented in two separate reports [9,10]. The data of reference 9 indicated that the surge flow induced solid velocity and the distance traversed by the solid increased with: (a) an increase in the volume of water used; (b) an increase in the pipe slope; and (c) a decrease in the diameter and length of the solid.…”