Calculation of friction losses, power, developed head and available Net Positive Suction Head of a pump 2. In the spreadsheet "Calculations" a. Insert the parameter values in the cells C21-C40 (yellow c - If there are not enlargements or contractions in the s b. Turn the "SWITCH" ON (set the value in the cell G1 (red cel c. Iterate (by pressing F9) until the value of " f " in the ce d. To recalculate for different parameter values turn the "SWI Equations that are being used in the calculations Calculation of the Fanning friction factor " f " In laminar flow, by using the equation: In turbulent flow, by using the Colebrook equation: Calculation of the friction losses In straight pipes In sudden enlargement In sudden contraction Available Net Positive Suction Head 1. On the Tools menu, click Options, then click the Calculation t - If the pump is below the liquid level in the suction t 1 √ f =−4 log 10 ( ε / D 3.7 + 1.255 Re √ f ) f= 16 Re h s = ΔP ρ = 4 f L D v 2 2 NPSH a = P−p v ρg + z 1 − ΣF s g h c =0.55 ( 1− A 2 A 1 ) 2 v 2 2 2 α h e = ( 1− A 1 A 2 ) 2 v 1 2 2 α
InstructionsCalculation of friction losses, power, developed
head andavailable Net Positive Suction Head of a pump1. On the
Tools menu, click Options, then click the Calculation tab and tick
on the Iteration box. On Maximum iterations box write 1000.2. In
the spreadsheet "Calculations"a. Insert the parameter values in the
cells C21-C40 (yellow cells)- If the pump is below the liquid level
in the suction tank, z1 (cell C38) is positive. If the pump is
above the liquid level in the suction tank, z1 is negative- If
there are not enlargements or contractions in the system, set
enlargement and/or contraction coefficients in the cells C27 and
C28 equal to 0b. Turn the "SWITCH" ON (set the value in the cell G1
(red cell) equal to 1 and press ENTER)c. Iterate (by pressing F9)
until the value of " f " in the cell H17 is constantd. To
recalculate for different parameter values turn the "SWITCH" OFF
(set the value in the cell G1 equal to 0 and press ENTER). Repeat
steps 2a to 2cEquations that are being used in the
calculationsCalculation of the Fanning friction factor " f "In
laminar flow, by using the equation:In turbulent flow, by using the
Colebrook equation:Calculation of the friction lossesIn straight
pipesIn sudden enlargementIn sudden contractionAvailable Net
Positive Suction Head
CalculationsCalculation of friction losses,SWITCH=1required
power, developed head andavailable NPSH of a pumpDerived dataMass
flow rate,=5.8333kg/sCross sectional areaA =0.00139m2Mean velocity
at point 2vm2 =4.010m/sReynolds numberRe =88419Relative rafnessrr
=0Corection factora=1ResultsFriction factorf =0.004714.614.7Input
dataFriction lossesFlow rateQ =20m3/hEnlargement lossesFe
=0.00J/kgInside diameterDi =0.042mContraction lossesFc
=4.42J/kgPipe lengthL =12mValve-equivalent lengthLeV =12.60mSuction
pipe lengthLs=2mFitting-equivalent lengthLeF =4.03mDensityden
=1050kg/m3Straight tube lossesFs
=103.26J/kgViscosityvisc=0.002PasTotal friction lossesFt
=107.68J/kgEnlargement-loss coefficientKe =0Contraction-loss
coefficientKc =0.55Energy and Power added to the fluid by the
pumpValves-loss equivalent lengthLe/D =300-ws
=213.8J/kgFittings-loss equvalent lengthLe/D =32-Ws =1247.3WNumber
of valvesNv =1Required Power (brake power)Number of fittings (90o
elbows)Nf =3-Wsr =-Wsr =1781.8WRafness of the piperaf =0mDeveloped
HeadVelocity at point 1v1=0m/sH =H =21.8mPressure at point
1P1=101325PaPressure at point 2P2=101325PaAvailable NPSHVapor
pressure in the suction linepv =12349PaFriction losses in the
suction lineDistance of point 1 from reference
levelz1*=-2-Contraction lossesFcs =4.42J/kgDistance of point 2 from
reference levelz2=8-Fitting-equivalent lengthLeFs =1.34mEfficiency
of the pumpn=70%-Straight tube lossesFss =12.06J/kgTotal friction
losses in the suction lineFts =17.83J/kg* If the pump is above the
liquid level in the suction tank, z1 is negativeNPSHa =4.8m
