Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed

Pipe wall friction for laminar and turbulent flow (detailed characteristic)

Information

This component defines the complete regime of wall friction. The details are described in the UsersGuide. The functional relationship of the friction loss factor λ is displayed in the next figure. Function massFlowRate_dp() defines the "red curve" ("Swamee and Jain"), where as function pressureLoss_m_flow() defines the "blue curve" ("Colebrook-White"). The two functions are inverses from each other and give slightly different results in the transition region between Re = 1500 .. 4000, in order to get explicit equations without solving a non-linear equation.

PipeFriction1.png

Additionally to wall friction, this component properly implements static head. With respect to the latter, two cases can be distinguished. In the case shown next, the change of elevation with the path from a to b has the opposite sign of the change of density.

PipeFrictionStaticHead_case-a.png

In the case illustrated second, the change of elevation with the path from a to b has the same sign of the change of density.

PipeFrictionStaticHead_case-b.png

Extends from PartialWallFriction (Partial wall friction characteristic (base package of all wall friction characteristics)).

Package Content

Name Description
Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.massFlowRate_dp massFlowRate_dp Return mass flow rate m_flow as function of pressure loss dp, i.e., m_flow = f(dp), due to wall friction
Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.pressureLoss_m_flow pressureLoss_m_flow Return pressure loss dp as function of mass flow rate m_flow, i.e., dp = f(m_flow), due to wall friction
Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.massFlowRate_dp_staticHead massFlowRate_dp_staticHead Return mass flow rate m_flow as function of pressure loss dp, i.e., m_flow = f(dp), due to wall friction and static head
Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.pressureLoss_m_flow_staticHead pressureLoss_m_flow_staticHead Return pressure loss dp as function of mass flow rate m_flow, i.e., dp = f(m_flow), due to wall friction and static head
Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.Internal Internal Functions to calculate mass flow rate from friction pressure drop and vice versa
Inherited
use_mu=true = true, if mu_a/mu_b are used in function, otherwise value is not used
use_roughness=true = true, if roughness is used in function, otherwise value is not used
use_dp_small=true = true, if dp_small is used in function, otherwise value is not used
use_m_flow_small=true = true, if m_flow_small is used in function, otherwise value is not used
dp_is_zero=false = true, if no wall friction is present, i.e., dp = 0 (function massFlowRate_dp() cannot be used)
use_Re_turbulent=true = true, if Re_turbulent input is used in function, otherwise value is not used

Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.massFlowRate_dp Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.massFlowRate_dp

Return mass flow rate m_flow as function of pressure loss dp, i.e., m_flow = f(dp), due to wall friction

Information

Extends from (Return mass flow rate m_flow as function of pressure loss dp, i.e., m_flow = f(dp), due to wall friction).

Inputs

NameDescription
dpPressure loss (dp = port_a.p - port_b.p) [Pa]
rho_aDensity at port_a [kg/m3]
rho_bDensity at port_b [kg/m3]
mu_aDynamic viscosity at port_a (dummy if use_mu = false) [Pa.s]
mu_bDynamic viscosity at port_b (dummy if use_mu = false) [Pa.s]
lengthLength of pipe [m]
diameterInner (hydraulic) diameter of pipe [m]
crossAreaInner cross section area [m2]
roughnessAbsolute roughness of pipe, with a default for a smooth steel pipe (dummy if use_roughness = false) [m]
dp_smallRegularization of zero flow if |dp| < dp_small (dummy if use_dp_small = false) [Pa]
Re_turbulentTurbulent flow if Re >= Re_turbulent (dummy if use_Re_turbulent = false) [1]

Outputs

NameDescription
m_flowMass flow rate from port_a to port_b [kg/s]

Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.pressureLoss_m_flow Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.pressureLoss_m_flow

Return pressure loss dp as function of mass flow rate m_flow, i.e., dp = f(m_flow), due to wall friction

Information

Extends from (Return pressure loss dp as function of mass flow rate m_flow, i.e., dp = f(m_flow), due to wall friction).

Inputs

NameDescription
m_flowMass flow rate from port_a to port_b [kg/s]
rho_aDensity at port_a [kg/m3]
rho_bDensity at port_b [kg/m3]
mu_aDynamic viscosity at port_a (dummy if use_mu = false) [Pa.s]
mu_bDynamic viscosity at port_b (dummy if use_mu = false) [Pa.s]
lengthLength of pipe [m]
diameterInner (hydraulic) diameter of pipe [m]
crossAreaInner cross section area [m2]
roughnessAbsolute roughness of pipe, with a default for a smooth steel pipe (dummy if use_roughness = false) [m]
m_flow_smallRegularization of zero flow if |m_flow| < m_flow_small (dummy if use_m_flow_small = false) [kg/s]
Re_turbulentTurbulent flow if Re >= Re_turbulent (dummy if use_Re_turbulent = false) [1]

Outputs

NameDescription
dpPressure loss (dp = port_a.p - port_b.p) [Pa]

Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.massFlowRate_dp_staticHead Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.massFlowRate_dp_staticHead

Return mass flow rate m_flow as function of pressure loss dp, i.e., m_flow = f(dp), due to wall friction and static head

Information

Extends from (Return mass flow rate m_flow as function of pressure loss dp, i.e., m_flow = f(dp), due to wall friction and static head).

Inputs

NameDescription
dpPressure loss (dp = port_a.p - port_b.p) [Pa]
rho_aDensity at port_a [kg/m3]
rho_bDensity at port_b [kg/m3]
mu_aDynamic viscosity at port_a (dummy if use_mu = false) [Pa.s]
mu_bDynamic viscosity at port_b (dummy if use_mu = false) [Pa.s]
lengthLength of pipe [m]
diameterInner (hydraulic) diameter of pipe [m]
g_times_height_abGravity times (Height(port_b) - Height(port_a)) [m2/s2]
crossAreaInner cross section area [m2]
roughnessAbsolute roughness of pipe, with a default for a smooth steel pipe (dummy if use_roughness = false) [m]
dp_smallRegularization of zero flow if |dp| < dp_small (dummy if use_dp_small = false) [Pa]
Re_turbulentTurbulent flow if Re >= Re_turbulent (dummy if use_Re_turbulent = false) [1]

Outputs

NameDescription
m_flowMass flow rate from port_a to port_b [kg/s]

Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.pressureLoss_m_flow_staticHead Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.pressureLoss_m_flow_staticHead

Return pressure loss dp as function of mass flow rate m_flow, i.e., dp = f(m_flow), due to wall friction and static head

Information

Extends from (Return pressure loss dp as function of mass flow rate m_flow, i.e., dp = f(m_flow), due to wall friction and static head).

Inputs

NameDescription
m_flowMass flow rate from port_a to port_b [kg/s]
rho_aDensity at port_a [kg/m3]
rho_bDensity at port_b [kg/m3]
mu_aDynamic viscosity at port_a (dummy if use_mu = false) [Pa.s]
mu_bDynamic viscosity at port_b (dummy if use_mu = false) [Pa.s]
lengthLength of pipe [m]
diameterInner (hydraulic) diameter of pipe [m]
g_times_height_abGravity times (Height(port_b) - Height(port_a)) [m2/s2]
crossAreaInner cross section area [m2]
roughnessAbsolute roughness of pipe, with a default for a smooth steel pipe (dummy if use_roughness = false) [m]
m_flow_smallRegularization of zero flow if |m_flow| < m_flow_small (dummy if use_m_flow_small = false) [kg/s]
Re_turbulentTurbulent flow if Re >= Re_turbulent (dummy if use_Re_turbulent = false) [1]

Outputs

NameDescription
dpPressure loss (dp = port_a.p - port_b.p) [Pa]
Automatically generated Thu Dec 19 17:20:10 2019.