Non-Circular Pipe - MapleSim Help

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Non-Circular Pipe

Lossy model of a non-circular pipe

 

Description

Equations

Variables

Connections

Parameters

Description

The Non-Circular Pipe component models a pipe with losses. The pressure drop is computed with the Darcy equation, with the friction factor determined using the Haaland approximation for turbulent flow. When the Reynolds number is greater than the maximum value for laminar flow but less than the minimum value for turbulent flow, the friction factor is determined using linear interpolation.

Equations

=qDhaν

fL=KsfT=fColebrookT,εDh

mode&equals;{posturbulentT<negturbulentT<posmixedL<negmixedL<laminarotherwise

p&equals;pApB&equals;12Lρν2Dh3{fColebrook&comma;εDhmode&equals;posturbulentmode&equals;negturbulentfL&plus;fTfLTLLmode&equals;posmixedmode&equals;negmixedKsotherwise

q&equals;qA&equals;qB&equals;AνDh

fColebrook&equals;&comma;εD1.8log106.9&plus;εD3.71.11−2

Variables

Name

Units

Description

Modelica ID

fL

1

Friction factor with laminar flow

fL

fT

1

Friction factor with turbulent flow

fT

mode

 

Integer indicating type of flow

mode

p

Pa

Pressure across component

p

q

m3s

Flow rate through component

q

1

Reynolds number

Re

Connections

Name

Description

Modelica ID

portA

Upstream port

portA

portB

Downstream port

portB

Parameters

Name

Default

Units

Description

Modelica ID

A

Dh2

m2

Cross-sectional area

A

Dh

0.01

m

Hydraulic diameter

Dh

Ks

56

1

Shape-factor for cross section

Ks

L

5

m

Length of pipe

L

ε

1.5·10−5

m

Height of inner surface roughness

epsilon

L

2·103

1

Reynolds number at transition to laminar flow

ReL

T

4·103

1

Reynolds number at transition to turbulent flow

ReT

See Also

Hydraulics Library

Restrictions