Friction Factors, Pumping and You Understanding how friction affects your bottom line

Introduction Sizing a pump properly saves money! Must overcome friction Watch out for cavitation!

Presentation Overview Understanding Friction Factors Fluid Flow Mechanics Trends in Friction Factors Experimental Procedure Results Conclusions

Understanding Friction Factors What are friction factors? –Energy Balance What goes in must come out (sort of…) –Bernoulli’s Equation Pressure Change ↓ ↑ Elevation Change ↑ Velocity ChangeFriction Losses ↑ Work In or Out ↓

Understanding Friction Factors Okay, but what is F? Friction Factor ↑ Egads, we’ve found one!

Trends in Friction Factors What effects a friction factor? –Properties of the pipe, i.e. roughness –Fluid properties and mechanics Laminar vs. Turbulent Flow

Trends in Friction Factors Reynolds Numbers –Accounts for velocity, geometry, density and viscosity, and how! Re<2000, Laminar Flow 2000<Re<4000, Transition 4000<Re, Turbulent Flow

Trends in Friction Factors Moody Diagrams –Based on experimental work –Gives Darcy friction factors by Reynolds number and pipe roughness –Resulting Equations for Fanning friction factors: Laminar Conditions: Turbulent Conditions:

Trends in Friction Factors

2 Methods to determine ‘f’: –Trust the Moody Diagram –Physical Experimentation Measure pressure drop over horizontal pipe

Experimental Procedure Two pipes selected with differing roughness A 2%wt solution of NaCl was run through pipes at various flowrates Pressure drop was measured across 10ft. sections of pipe.

Results

Conclusions and Recommendations Overall trend of Moody diagram is very accurate Moody diagram gives a good estimate for friction factors Additional tests should be performed using longer pipes Minimal friction is money saved

Review Understanding Friction Factors Fluid Flow Mechanics Trends in Friction Factors Experimental Procedure Results Conclusions

Gratitude Thanks to lab partners: –Mike Mellas –Allyson Lundberg Fluid mechanics theory and equations: –Dr. Eric Eddings –de Nevers, Noel. Fluid Mehanics for Chemical Engineers (Third Edition). New York: McGraw-Hill, 2005.

Q&A Time! Questions?