الفهرس 
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Abstract
Experimental study to obtain energy loss data for a threaded sharp-edged dividing pipe junction is conducted. Experiments are conducted on nine junctions and the obtained data cover ratios of branch to main pipe cross-sectional area A,,/ Au ranging from 0.299
to 1.0; ratios of branch to main pipe discharge Q,,/Qu ranging from 0 to I; and three branch angles (ex” = 45°, 90°, and 135°). Flow Reynolds number in the main pipe is 0.767 x 105. At flow situations defined by these ranges and angles above, there are few cncrgy loss data available and no satisfactory theory, and almost all available data are for sl1100lh junctions.
To carry-out the experimental investigation, a testing apparatus was designed and constructed as a closed circuit. Experiments utilized a 5-m long, 2 inch diameter plastic pipe [PVC] with a vertical branch pipe entering about 50 pipe diameter downstream from the upstream end of the main-pipe. The water pressure-head in the main pipe sections and in the branch pipe section was measured relative to the pressure-head at the upstream section of the junction using V-tubes manometers. The volumetric discharges through the branch and downstream pipes was measured. Water temperature was also measured and monitored.
The cxperimental results are analyzed and presented for each of the nine junctions.
The effects of the area ratio A b / Au; flow rate ratio Q b / Q u ; and branch angle ex b on
the energy loss coefficients (Kud, Kuh, and Ktot) are computed. The precision uncertainties are found to be always less than ± 10.78%, ±8.79%, and ± 1 0.76% for the coefficients Kilt!. KII’” and Klol, respectively. For each junction. the energy loss coefficient
The energy loss between upstream and downstream of the junction is found t slitdllly afJi-cled bv flow nlte ratio Qh!<)”, whereas the energy loss hetween the bl”
Polynomial empirical equations defining the coefficients of threaded junctions also presented, and compared to the coefficients of smooth junctions found in the literat The comparison shows that the coefficients of threaded junction are always larger t those of smooth one.
The study assures that the loss is an energy concept and comes only from en equation and the assumption that the losses are found from Bernoulli equation is not true (Bcrnoulli’s equation is derived from momentum equation and can not have a ”loss term”)