Agenda | General | Engineering | Hydraulic | Pressurized flow


Flow conditions:

Re < 2300 : Laminar flow
2300 < Re < 4000 : Transition zone
Re > 4000 : Turbulent flow

Q : Flow discharge [m³/s]
A : Wet area [m²]
P : Wet perimeter [m]
D0 : Pipe diameter [m]
V : Flow velocity [m/sn]
R : Hydraulic radius [m]
D : Hydraulic depth [m]
Re : Reynold number [-]
ν : Kinematic viscosity [0.000001004 m²/sn]


Energy equation (Bernoulli)


E : Total energy [m]
ΔH : Energy loss [m]
H : Piezometric level [m]
P : Pressure [m]
Z : Flow level [m]
L : Flow line length [m]
V : Flow velocity [m/s]
S : Slope [-]
g : Gravitational acceleration [9.81 m²/s]
γ : Specific weight [20°C : 9.789 kN/m³]


Energy loss

ΔH : Total loss [m]
ΔHF : Friction loss [m]
ΔHM : Minor losses [m]
L : Flow line length [m]
J : Unit friction loss [m/m]
K : Local loss coefficient [-]
V : Flow velocity [m/s]
g : Gravitational acceleration [9.81 m²/s]


Friction loss / Darcy-Weisbach formula

J : Unit friction loss [m/m]
V : Flow velocity [m/s]
D : Hydraulic depth [m]
g : Gravitational acceleration [9.81 m²/s]
f : Friction coefficient [-]
Re : Reynold number [-]

Ks : Equivalent roughness height [m]
----------------------------------------
Plastic pipe : Ks=0.0015 mm
Ductile iron pipe : Ks=0.26 mm
Steel pipe : Ks=0.045 mm


Friction loss / William-Hazen formula

J : Unit friction loss [m/m]
Q : Flow discharge [m³/s]
D : Pipe inner diameter [m]
C : Friction coefficient [-]
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Plastic pipe : C=140
Ductile iron pipe : C=140
Steel pipe : C=110