Low Pressure Air Calculators

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Low Pressure Air Pressure Loss From The Moody Diagram

Calculate pressure loss for low pressure air circular and rectangular ducts using the Moody diagram.

The calculators use the Darcy-Weisbach pressure loss equation. For low Reynolds numbers Re < 2000, the fluid flow is laminar and the Darcy friction factor should be calculated using the Hagen-Poiseuille laminar flow equation. For high Reynolds numbers Re > 4000, the fluid flow is turbulent and the Darcy friction factor should be calculated using one of the turbulent flow equations. In the transition region 2000 < Re < 4000, the flow is unstable and the friction loss cannot be reliably calculated.

Minor losses can be entered as either a K friction factor, a length, or length over diameter ratio. The minor losses are used to account for pipeline fittings such as bends, tees, valves etc.. :sg:For air the gas specific gravity SG = 1.0. For low pressure air the compressibility factor is assumed equal to one.

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CALCULATOR : Low Pressure Air Circular Duct Pressure Loss From From Moody Diagram [FREE] ±

Calculate low pressure air circular duct outlet pressure from flow rate and diameter using the Moody diagram.

The Moody diagram combines the Hagen-Poiseuille laminar flow equation with the Colebrook White turbulent flow equation (either the original Colebrook White equation or the modified Colebrook White equation). Viscosity is calculated from temperature using the Sutherland law. Elevation is ignored.

Tool Input

schdtype : Pipe Schedule Type
diamtype : Pipe Diameter Type
- ODu : User Defined Outside Diameter
- IDu : User Defined Inside Diameter
wtntype : Wall Thickness Type
- tnu : User Defined Wall Thickness
voltype : Fluid Flow Rate Type
- Qfu : User Defined Gas Volume Flow Rate
- Mfu : User Defined Gas Mass Flow Rate
- Ngu : User Defined Gas Mole Flow Rate
- Vfu : User Defined Gas Velocity
- Reu : User Defined Reynolds Number
rfactype : Pipe Internal Roughness Type
- ru : User Defined Surface Roughness
- rru : User Defined Relative Roughness
fdtype : Darcy Friction Factor Type
- fdu : User Defined Darcy Friction Factor
flowtype : Pressure For Fluid Property Calculation
L : Pipe Length
K : K Factor
Pi : Inlet Pressure
T : Fluid Temperature

Tool Output

ΔP : Friction Pressure Loss
μ : Dynamic Viscosity
ρ : Fluid Density (At Pf)
ID : Inside Diameter
Mf : Mass Flowrate
Ng : Mole Flow Rate
Pa : Average Fluid Pressure
Pf : Pressure For Fluid Property Calculation
Po : Outlet Pressure
Qf : Volume Flowrate (At Pf)
Re : Reynolds Number (At Inlet)
Vf : Fluid Velocity (At Pf)
cvg : Convergence Factor (≅ 1)
fd : Darcy Friction Factor
ff : Fanning Friction Factor
rr : Surface Roughness Ratio
td : Darcy Transmission Factor
tf : Fanning Transmission Factor
vg : Mole Specific Volume (At Pf)

CALCULATOR : Low Pressure Air Rectangular Duct Pressure Loss From Moody Diagram [FREE] ±

Calculate low pressure air rectangular duct outlet pressure from flow rate and diameter using the Moody diagram.

The Moody diagram combines the Hagen-Poiseuille laminar flow equation with the Colebrook White turbulent flow equation (either the original Colebrook White equation or the modified Colebrook White equation). The hydraulic diameter is equal to four times the cross section area divided by the perimeter. Elevation is ignored.

Tool Input

voltype : Fluid Flow Rate Type
- Qfu : User Defined Gas Volume Flow Rate
- Mfu : User Defined Gas Mass Flow Rate
- Ngu : User Defined Gas Mole Flow Rate
- Vfu : User Defined Gas Velocity
- Reu : User Defined Reynolds Number
rfactype : Pipe Internal Roughness Type
- ru : User Defined Surface Roughness
- rru : User Defined Relative Roughness
fdtype : Darcy Friction Factor Type
- fdu : User Defined Darcy Friction Factor
flowtype : Pressure For Fluid Property Calculation
W : Duct Width
H : Duct Height
L : Pipe Length
K : K Factor
Pi : Inlet Pressure
T : Fluid Temperature

Tool Output

ΔP : Friction Pressure Loss
μ : Dynamic Viscosity
ρ : Fluid Density (At Pf)
ID : Hydraulic Diameter
Mf : Mass Flowrate
Ng : Mole Flow Rate
Pa : Average Fluid Pressure
Pf : Pressure For Fluid Property Calculation
Po : Outlet Pressure
Qf : Volume Flowrate (At Pf)
Re : Reynolds Number (At Inlet)
Vf : Fluid Velocity (At Pf)
cvg : Convergence Factor (≅ 1)
fd : Darcy Friction Factor
ff : Fanning Friction Factor
rr : Surface Roughness Ratio
td : Darcy Transmission Factor
tf : Fanning Transmission Factor
vg : Mole Specific Volume (At Pf)

Low Pressure Air Pressure Loss From The Moody Diagram

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