Question

VENTURI METER Problem 6 - 44 A vertical Venturi meter, 150 nm in diameter is connected to a 300-mm diameter pipe. The vertical distance from the inlet to the throat being 750 nm. If the deflection of mercury in the differential manometer connected from the inlet to the throat is 360 mm, determine the flow of water through the meter if the meter coefficient is 0.68. Determine also the head lost from the inlet to the throat 750 mm 360 mm Mercury $ 33.6

Answer 1

bot Griven dato coefficient of discharge (cd) = 0.68 Diameter at inlet - 300mm. (di) Area (a) = II dir = I x 3007 = 70685.83 mm = 0.070 685 m Diameter at throat (d) = 150mm. Area (az) = II dr = I x 150 = 1767114 mm = 0.017671 m2 450 mm Waters=100 WUCOS 364 mm Difference in elevation between inlet and throat - z-Z, = 750mm. Mercury S = 13.6 Specific gravity of water = 1 Specific gravity of mercury = (Sg) = 13.6 Reading of difference in manometer En ) = 360mm.

X *1*:-) - 540(136-17 = 4536 mm of water = 4.536 m. Discharge out of water Q = ca a, a, ra? - az x Sagh =0.68 x 0.070 685 Xo.017671 x 2 x9-81 X4536 V60-070 685)-(0.019671)2 = 0.117 m3/s = 117 litres/ sec. Head lost from intet to theiate hul Apply Bernoute's equation at ① & ② Sections, we get Pg 12: Test the 29 Q = a, u =) = 1-655mls Q = Q, V = 0.117 0.070685 0.117 - 0.017671 = 6.62 m/s

4.536 + (1.665" - 6:62") 2 x 9.8 h CN 4,536 - 2-09 -h, h = 2.44 m of water,