WOLFRAM SYSTEMMODELER

StaticPipe

Basic pipe flow model without storage of mass or energy

Diagram

Wolfram Language

In[1]:=
SystemModel["Modelica.Fluid.Pipes.StaticPipe"]
Out[1]:=

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

Model of a straight pipe with constant cross section and with steady-state mass, momentum and energy balances, i.e., the model does not store mass or energy. There exist two thermodynamic states, one at each fluid port. The momentum balance is formulated for the two states, taking into account momentum flows, friction and gravity. The same result can be obtained by using DynamicPipe with steady-state dynamic settings. The intended use is to provide simple connections of vessels or other devices with storage, as it is done in:

Numerical Issues

With the stream connectors the thermodynamic states on the ports are generally defined by models with storage or by sources placed upstream and downstream of the static pipe. Other non storage components in the flow path may yield to state transformation. Note that this generally leads to nonlinear equation systems if multiple static pipes, or other flow models without storage, are directly connected.

Parameters (13)

allowFlowReversal

Value: system.allowFlowReversal

Type: Boolean

Description: = true to allow flow reversal, false restricts to design direction (port_a -> port_b)

nParallel

Value: 1

Type: Real

Description: Number of identical parallel pipes

length

Value:

Type: Length (m)

Description: Length

isCircular

Value: true

Type: Boolean

Description: = true if cross sectional area is circular

diameter

Value:

Type: Diameter (m)

Description: Diameter of circular pipe

crossArea

Value: Modelica.Constants.pi * diameter * diameter / 4

Type: Area (m²)

Description: Inner cross section area

perimeter

Value: Modelica.Constants.pi * diameter

Type: Length (m)

Description: Inner perimeter

roughness

Value: 2.5e-5

Type: Roughness (m)

Description: Average height of surface asperities (default: smooth steel pipe)

V

Value: crossArea * length * nParallel

Type: Volume (m³)

Description: volume size

height_ab

Value: 0

Type: Length (m)

Description: Height(port_b) - Height(port_a)

p_a_start

Value: system.p_start

Type: AbsolutePressure (Pa)

Description: Start value of pressure at port a

p_b_start

Value: p_a_start

Type: AbsolutePressure (Pa)

Description: Start value of pressure at port b

m_flow_start

Value: system.m_flow_start

Type: MassFlowRate (kg/s)

Description: Start value for mass flow rate

Connectors (2)

port_a

Type: FluidPort_a

Description: Fluid connector a (positive design flow direction is from port_a to port_b)

port_b

Type: FluidPort_b

Description: Fluid connector b (positive design flow direction is from port_a to port_b)

Components (2)

system

Type: System

Description: System wide properties

flowModel

Type: FlowModel

Description: Flow model

Used in Examples (13)

PumpingSystem

Modelica.Fluid.Examples

Model of a pumping system for drinking water

ThreeTanks

Modelica.Fluid.Examples.Tanks

Demonstrating the usage of SimpleTank

TanksWithOverflow

Modelica.Fluid.Examples.Tanks

Two tanks connected with pipes at different heights

EmptyTanks

Modelica.Fluid.Examples.Tanks

Show the treatment of empty tanks

BatchPlant_StandardWater

Modelica.Fluid.Examples.AST_BatchPlant

OneTank

Modelica.Fluid.Examples.AST_BatchPlant.Test

Tank with one time-varying top inlet mass flow rate and a bottom outlet into the ambient

TwoTanks

Modelica.Fluid.Examples.AST_BatchPlant.Test

TankWithEmptyingPipe1

Modelica.Fluid.Examples.AST_BatchPlant.Test

Demonstrates a tank with one constant top inlet mass flow rate and a bottom outlet into the ambient

TankWithEmptyingPipe2

Modelica.Fluid.Examples.AST_BatchPlant.Test

Demonstrates a tank with one constant top inlet mass flow rate and a bottom outlet into the ambient

TanksWithEmptyingPipe1

Modelica.Fluid.Examples.AST_BatchPlant.Test

Demonstrates a tank with one constant top inlet mass flow rate and a bottom outlet into the ambient

TanksWithEmptyingPipe2

Modelica.Fluid.Examples.AST_BatchPlant.Test

Demonstrates a tank with one constant top inlet mass flow rate and a bottom outlet into the ambient

RoomCO2

Modelica.Fluid.Examples.TraceSubstances

Demonstrates a room volume with CO2 accumulation

InverseParameterization

Modelica.Fluid.Examples

Demonstrates the parameterization of a pump and a pipe for given nominal values