PipeFlow

PipeFlow_f

Procedure PipeFlow_f( Fluid$, T, P, m_dot, D, L,RelRough: DELTAP, f, Re) returns the pressure drop and friction factor for a specified mass flow rate (m_dot) through a circular tube of diameter D and length L. Units of the inputs and outputs depend upon the unit settings in EES.

Inputs:
Fluid$ can be any fluid in the EES database. The fluid can be an ideal gas, a real fluid, a brine, or a fluid from the Compressible substance library.
T - the bulk temperature of the fluid in [C], [K], [F], or [R].
P - pressure can be in [Pa], [kPa], [bar], [MPa], [atm], or [psia]. (Note that for brines, this parameter provides the concentration in %)
m_dot - mass flow rate in [kg/s], or [lbm/hr]
D - diameter of the tube in [m] or [ft]
L - length of the tube in [m] or [ft]
RelRough - the ratio of the dispersions on the wall of the tube to the tube diameter (must be between 0 and 0.05)

Outputs: {only the 1st output is required}
DELTAP - pressure difference between the inlet and outlet of the pipe in the pressure units set in the EES Unit System dialog
f - friction factor [-]
Re - Reynolds number [-]

Notes
The procedure will determine if the flow is laminar or turbulent. Transitional flow is assumed to occur for Reynold's numbers between 2300 and 3000 and interpolation is applied between the laminar and turbulent correlations. The ratio of L/D is used to apply a developing flow correction; set L to a large number if developing flow corrections are not applicable.

Inputs and outputs in the Call statement are separated with a list separator character, which is a comma in the US system and a semicolon in the European system.

Example:
$UnitSystem SI K Pa J
$VarInfo DELTAP units=Pa
T=363 [K]                      "average temperature of fluid in pipe"
P=101300 [Pa]               "pressure of air in pipe"
m_dot=0.05 [kg/s]           "flow rate"
D=0.15 [m]                     "pipe diameter"
L=500 [m]                       "pipe length"
RelRough=0                    "relative roughness"
Call pipeflow_f('Air', T, P, m_dot, D, L,RelRough: DELTAP, f, Re)

{Solution:
DELTAP=357 [Pa]
f=0.02601
Re=19851
}

Minor Losses Index