Modelica.Fluid.Dissipation.PressureLoss.Orifice

Information

Orifice

Sudden change

Calculation of the local pressure loss at a sudden change of the cross sectional areas (sudden expansion or sudden contraction) with sharp corners at turbulent flow regime for incompressible and single-phase fluid flow through arbitrary shaped cross sectional area (square, circular, etc.) considering a smooth surface. See more information.

Thick edged orifice

Calculation of pressure loss in thick edged orifices with sharp corners at overall flow regime for incompressible and single-phase fluid flow through an arbitrary shaped cross sectional area (square, circular, etc.) considering constant influence of surface roughness. See more information.

Package Content

Name	Description
dp_suddenChange_DP	Pressure loss of orifice with sudden change in cross sectional area | calculate pressure loss | turbulent flow regime | smooth surface | arbitrary cross sectional area | without buffles | sharp edge
dp_suddenChange_MFLOW	Pressure loss of orifice with sudden change in cross sectional area | calculate mass flow rate | turbulent flow regime | smooth surface | arbitrary cross sectional area | without buffles | sharp edge
dp_suddenChange_IN_con	Input record for function dp_suddenChange_DP and dp_suddenChange_MFLOW
dp_suddenChange_IN_var	Input record for function dp_suddenChange_DP and dp_suddenChange_MFLOW
dp_thickEdgedOverall_DP	Pressure loss of thick and sharp edged orifice | calculate pressure loss | overall flow regime | constant influence of friction | arbitrary cross sectional area
dp_thickEdgedOverall_MFLOW	Pressure loss of thick and sharp edged orifice | calculate mass flow rate | overall flow regime | constant influence of friction | arbitrary cross sectional area
dp_thickEdgedOverall_IN_con	Input record for function dp_thickEdgedOverall_DP and dp_thickEdgedOverall_MFLOW
dp_thickEdgedOverall_IN_var	Input record for function dp_thickEdgedOverall_DP and dp_thickEdgedOverall_MFLOW

Modelica.Fluid.Dissipation.PressureLoss.Orifice.dp_suddenChange_DP

Information

Calculation of the local pressure loss at a sudden change of the cross sectional areas (sudden expansion or sudden contraction) with sharp corners at turbulent flow regime for incompressible and single-phase fluid flow through arbitrary shaped cross sectional area (square, circular, etc.) considering a smooth surface. The flow direction determines the type of the transition. In case of the design flow a sudden expansion will be considered. At flow reversal a sudden contraction will be considered.

Generally this function is numerically best used for the incompressible case , where the mass flow rate (m_flow) is known (as state variable) in the used model and the corresponding pressure loss (DP) has to be calculated. On the other hand the function dp_suddenChange_MFLOW is numerically best used for the compressible case if the pressure loss (dp) is known (out of pressures as state variable) and the mass flow rate (M_FLOW) has to be calculated. See more information.

Inputs

Name	Description
Constant inputs
IN_con	Input record for function dp_suddenChange_DP
Variable inputs
IN_var	Input record for function dp_suddenChange_DP
Input
m_flow	Mass flow rate [kg/s]

Outputs

Name	Description
DP	Output for function dp_suddenChange_DP [Pa]

Modelica.Fluid.Dissipation.PressureLoss.Orifice.dp_suddenChange_MFLOW

Information

Calculation of the local pressure loss at a sudden change of the cross sectional areas (sudden expansion or sudden contraction) with sharp corners at turbulent flow regime for incompressible and single-phase fluid flow through arbitrary shaped cross sectional area (square, circular, etc.) considering a smooth surface. The flow direction determines the type of the transition. In case of the design flow a sudden expansion will be considered. At flow reversal a sudden contraction will be considered.

Generally this function is numerically best used for the compressible case if the pressure loss (dp) is known (out of pressures as state variable) and the mass flow rate (M_FLOW) has to be calculated. On the other hand the function dp_suddenChange_DP is numerically best used for the incompressible case , where the mass flow rate (m_flow) is known (as state variable) in the used model and the corresponding pressure loss (DP) has to be calculated. See more information.

Inputs

Name	Description
Constant inputs
IN_con	Input record for function dp_suddenChange_MFLOW
Variable inputs
IN_var	Input record for function dp_suddenChange_MFLOW
Input
dp	Pressure loss [Pa]

Outputs

Name	Description
M_FLOW	Output for function dp_suddenChange_MFLOW [kg/s]

Modelica.Fluid.Dissipation.PressureLoss.Orifice.dp_suddenChange_IN_con

Information

Parameters

Name	Description
Orifice
A_1	Small cross sectional area of orifice [m2]
A_2	Large cross sectional area of orifice [m2]
C_1	Small perimeter of orifice [m]
C_2	Large perimeter of orifice [m]

Modelica.Fluid.Dissipation.PressureLoss.Orifice.dp_suddenChange_IN_var

Information

Parameters

Name	Description
Fluid properties
eta	Dynamic viscosity of fluid [Pa.s]
rho	Density of fluid [kg/m3]

Modelica.Fluid.Dissipation.PressureLoss.Orifice.dp_thickEdgedOverall_DP

Information

Calculation of pressure loss in thick edged orifices with sharp corners at overall flow regime for incompressible and single-phase fluid flow through an arbitrary shaped cross sectional area (square, circular, etc.) considering constant influence of surface roughness.

Generally this function is numerically best used for the incompressible case , where the mass flow rate (m_flow) is known (as state variable) in the used model and the corresponding pressure loss (DP) has to be calculated. On the other hand the function dp_thickEdgedOverall_MFLOW is numerically best used for the compressible case if the pressure loss (dp) is known (out of pressures as state variable) and the mass flow rate (M_FLOW) has to be calculated. See more information.

Inputs

Name	Description
Constant inputs
IN_con	Input record for function dp_thickEdgedOverall_DP
Variable inputs
IN_var	Input record for function dp_thickEdgedOverall_DP
Input
m_flow	Mass flow rate [kg/s]

Outputs

Name	Description
DP	Output for function dp_thickEdgedOverall_DP [Pa]

Modelica.Fluid.Dissipation.PressureLoss.Orifice.dp_thickEdgedOverall_MFLOW

Information

Calculation of pressure loss in thick edged orifices with sharp corners at overall flow regime for incompressible and single-phase fluid flow through an arbitrary shaped cross sectional area (square, circular, etc.) considering constant influence of surface roughness.

Generally this function is numerically best used for the compressible case , where the pressure loss (dp) is known (out of pressures as state variable) in the used model and the corresponding mass flow rate (M_FLOW) has to be calculated. On the other hand the function dp_thickEdgedOverall_DP is numerically best used for the incompressible case if the mass flow rate (m_flow) is known (as state variable) and the pressure loss (DP) has to be calculated. See more information.

Inputs

Name	Description
Constant inputs
IN_con	Input record for function dp_thickEdgedOverall_MFLOW
Variable inputs
IN_var	Input record for function dp_thickEdgedOverall_MFLOW
Input
dp	Pressure loss [Pa]

Outputs

Name	Description
M_FLOW	Output for function dp_thickEdgedOverall_MFLOW [kg/s]

Modelica.Fluid.Dissipation.PressureLoss.Orifice.dp_thickEdgedOverall_IN_con

Information

Parameters

Name	Description
Orifice
A_0	Cross sectional area of vena contraction [m2]
C_0	Perimeter of vena contraction [m]
A_1	Large cross sectional area of orifice [m2]
C_1	Large perimeter of orifice [m]
L	Length of vena contraction [m]
Linearisation
dp_smooth	Start linearisation for decreasing pressure loss [Pa]

Modelica.Fluid.Dissipation.PressureLoss.Orifice.dp_thickEdgedOverall_IN_var

Information

Parameters

Name	Description
Fluid properties
eta	Dynamic viscosity of fluid [Pa.s]
rho	Density of fluid [kg/m3]