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Toolbox. Reynolds Number Relative roughness Darcy Equation HP Equation Moody Chart. More Toolbox. Explicit equation Hazen- Williams Hydraulic radius HW Coefficient. Hazen-Williams. Empirical: equation fitted to data on water at 60 o F, pipe diameter >2in., water velocity < 10fps
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Toolbox • Reynolds Number • Relative roughness • Darcy Equation • HP Equation • Moody Chart
More Toolbox • Explicit equation • Hazen- Williams • Hydraulic radius • HW Coefficient
Hazen-Williams • Empirical: equation fitted to data on water at 60oF, pipe diameter >2in., water velocity < 10fps • Water works primary use • V = 1.318CHWRH0.63S0.54 (USCS) • CHW – roughness coefficient • RH – hydraulic radius • S – energy gradient
Friction • Pipe – Darcy Equation • Minor losses • Fittings • Valves • Special purpose components
Minor Losses • Head loss: streamline separation • Loss coefficient
Minor Losses • Fittings • Valves • P loss due to change in • Direction • Velocity
Loss Coefficients K = 0.5 K = .07 For 60o K = 1.0 K = 0.3
Minor losses • Equivalent length • hf = f (Le/D)(V2/2g) • Wide-open gate valve: K = 10 • Wide-open gate valve: Le = 340
Minor Losses • Inlet/exit • Expansion/ contraction • Bends/elbows • Valves • Globe • Needle • Gate • Ball • Check • Butterfly • Diaphram
Loss Coefficient • hL = K V2/2g
Minor Losses • Equivalent length • LE/D • fT
References • Images & examples • Mechanics of Fluids, 3rd Edition, Potter & Wiggert, Brooks & Cole • Applied Fluid Mechanics, 6th Edition, Mott, Prentice Hall • Engineering Fluid Mechanics, 5th Edition Crowe, & Roberson, Wiley • Fluid Mechanics Cengel & Cimbala McGraw Hill