THE FLOW OF WATER IN WOOD-STAVE PIPE. 



25 



Table 1. — Velocities by color (fluorescein) compared with velocities by weir and current 



meter. 



Refer- 

 ence 

 No. 



Pipe 

 diam- 

 eter. 



Crest length of 

 weir. 



Meter method. 



Velocity 

 per second 

 by color. 



Vc 



Velocity 

 per second 

 by meter. 



Vm 



Velocity 

 per sec- 

 ond by 

 weir. 



Vo-Vm 



V, 



v„-v„ 



Vc 



60 



Inches. 



8 



8 



8 



8 



8 



18 



36 



36 



48 



48 



48 



78 



78 



78 



78 



78 



78 



78 



78 



Feet. 

 l.OSCip.i 





Feet. 

 1.251 

 1.736 

 2.048 

 3.043 

 3.294 

 2.08 

 3.48 

 3.48 

 3.14 

 3.75 

 4.75 

 0.911 

 0.963 

 1.51 

 2.063 

 2.16 

 2.40 

 2.44 

 2.79 



Feet. 



Feet. 

 1.295 

 1.735 

 2.09 

 2.97 

 3.37 



Per cent. 



Per cent. 

 -3.8 



61 



do 









+0.1 



62 



2.84Reet.2. ... 









—2.0 



63 



do 









+2.4 



64 



do 









—2.4 



132 





6-tenths3 



Int.5 



1.99 



3.48 



3.55 



3.05 



3.71 



4.73 



0.928 



0.974 



1.60 



2.08 



2.10 



2.37 



2.42 



2.51 



+4.3 

 0.0 

 -2.0 

 +2.9 

 +1.1 

 +0.4 

 -1.9 

 -1.1 

 -6.0 

 -1.0 

 +2.8 

 +1.2 

 +0.8 

 +3.1 





192 



lO.OCip.i 



do 



3.47 

 3.47 



+0.3 



6-tenths3 



2+8' 



+0.3 



193 





do 







194 





....do 







263 





Curves 



. ..do 







264 









265 





do 







266 





do 







(^) 





do 







269 





do 







270 





.do 







271 





do 

















1 CipoUetti weir with good conditions of contraction and velocity. See p. 40. 



s Rectangular weir with end contractions and sharp crest. See p. 40. 



3 Meter held in each vertical at 0.6 depth from sm'face. 



* From tests on a concrete pipe, made in 1915. 



6 Velocity integrated by moving meter slowly from top to bottom and return. 



8 Excluded from Table 2 because gauge data lost for manometer No. 1. 



' Meter held at 0.2 and 0.8 depths in each vertical; mean accepted for vertical. 



See p. 44. 



8 Rating curve developed by meter measurements. Velocity taken from curve. See p. 45 



FIELD PROCEDURE. 



After the reach of pipe was selected, the manometers attached, 

 and other equipment put in readiness the method for proceeding 

 with the field test was in general carried out as described in the 

 paragraphs following. Any necessary changes are noted in the text 

 in connection with the description of the individual pipes tested. 



The watches used at both ends of the reach were adjusted to agree 

 to the second, and again compared at the end of the observation. 

 Manometers were read every one or two minutes (depending on the 

 amount of pulsation in the water) for a period of 30 minutes. If a 

 weir was used to nieasure the discharge of water a hook gauge above 

 the weir was read every two to five minutes, depending on the varia- 

 tion of discharge. If a current meter measurement was necessary 

 to determine the discharge it was made either during or immediately 

 following the series of manometer readings, the manometers being 

 watched for appreciable variations of discharge. Where fluorescein 

 was used to time the actual velocity of the water it was injected into 

 the pipe at approximately known intervals, say, five minutes, through- 

 out the time during which the manometers were read. Ordinarily 

 the second gauge was near enough to the outlet of the pipe so that 

 one observer could both read the manometer and watch for the 

 appearance of the color. Sometimes a third observer was necessary. 



