Modelica.Fluid.Fittings.BaseClasses.Bends.CurvedBend

Information

This package contains utility functions and records for the CurvedBend fitting component.

Package Content

Name	Description
massFlowRate	Return mass flow rate m_flow as function of pressure loss dp for a curved bend
pressureLoss	Return pressure loss dp as function of mass flow rate m_flow for a curved bend
Geometry	Geometric data for a curved bend

Modelica.Fluid.Fittings.BaseClasses.Bends.CurvedBend.massFlowRate

Information

This function returns the mass flow rate m_flow as function of pressure loss dp for a curved bend. The details of the function are described here.

The bend characteristic is valid for constant density and constant dynamic viscosity. It can be approximately also used for compressible media. This is performed by providing the upstream density and upstream dynamic viscosity. In order to be able to regularize density and dynamic viscosity around zero mass flow rate, the two quantities have to be given if fluid flows from port_a to port_b (d_a, eta_a) and if fluid flows from port_b to port_a (d_b, eta_b).

Inputs

Name	Description
dp	Pressure loss [Pa]
geometry	Geometry of bend
d_a	Density at port_a when fluid is flowing from port_a to port_b [kg/m3]
d_b	Density at port_b when fluid is flowing from port_b to port_a [kg/m3]
eta_a	Dynamic viscosity at port_a when fluid is flowing from port_a to port_b [Pa.s]
eta_b	Dynamic viscosity at port_b when fluid is flowing from port_b to port_a [Pa.s]
dp_small	Small pressure drop used for regularization if m_flow=f(...,dp_small,..,dp) [Pa]
m_flow_small	Small mass flow rate used for regularization if dp=f_inv(...,m_flow_small,m_flow) [kg/s]

Outputs

Name	Description
m_flow	Mass flow rate (= port_a.m_flow) [kg/s]

Modelica.Fluid.Fittings.BaseClasses.Bends.CurvedBend.pressureLoss

Information

This function returns the pressure loss dp as function of mass flow rate m_flow for a curved bend. The details of the function are described here.

The bend characteristic is valid for constant density and constant dynamic viscosity. It can be approximately also used for compressible media. This is performed by providing the upstream density and upstream dynamic viscosity. In order to be able to regularize density and dynamic viscosity around zero mass flow rate, the two quantities have to be given if fluid flows from port_a to port_b (d_a, eta_a) and if fluid flows from port_b to port_a (d_b, eta_b).

Inputs

Name	Description
m_flow	Mass flow rate (= port_a.m_flow) [kg/s]
geometry	Geometry of bend
d_a	Density at port_a when fluid is flowing from port_a to port_b [kg/m3]
d_b	Density at port_b when fluid is flowing from port_b to port_a [kg/m3]
eta_a	Dynamic viscosity at port_a when fluid is flowing from port_a to port_b [Pa.s]
eta_b	Dynamic viscosity at port_b when fluid is flowing from port_b to port_a [Pa.s]
dp_small	Small pressure drop used for regularization if m_flow=f(...,dp_small,..,dp) [Pa]
m_flow_small	Small mass flow rate used for regularization if dp=f_inv(...,m_flow_small,m_flow) [kg/s]

Outputs

Name	Description
dp	Pressure loss [Pa]

Modelica.Fluid.Fittings.BaseClasses.Bends.CurvedBend.Geometry

Information

This record is used to define the geometric (constant) data of a curved bend. The details of the record are described here.

Parameters

Name	Description
d_hyd	Hydraulic diameter [m]
R_0	Curvature radius [m]
delta	Angle of turning [rad]
K	Absolute roughness, with a default for a smooth steel pipe [m]