Package 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 Modelica.​Fluid.​Pipes.​BaseClasses.​WallFriction.​PartialWallFriction (Partial wall friction characteristic (base package of all wall friction characteristics)).

Package Contents

NameDescription
InternalFunctions to calculate mass flow rate from friction pressure drop and vice versa
massFlowRate_dpReturn mass flow rate m_flow as function of pressure loss dp, i.e., m_flow = f(dp), due to wall friction
massFlowRate_dp_staticHeadReturn mass flow rate m_flow as function of pressure loss dp, i.e., m_flow = f(dp), due to wall friction and static head
pressureLoss_m_flowReturn pressure loss dp as function of mass flow rate m_flow, i.e., dp = f(m_flow), due to wall friction
pressureLoss_m_flow_staticHeadReturn pressure loss dp as function of mass flow rate m_flow, i.e., dp = f(m_flow), due to wall friction and static head

Package Constants

TypeNameValueDescription
Booleandp_is_zerofalse= true, if no wall friction is present, i.e., dp = 0 (function massFlowRate_dp() cannot be used)
final Booleanuse_dp_smalltrue= true, if dp_small is used in function, otherwise value is not used
final Booleanuse_m_flow_smalltrue= true, if m_flow_small is used in function, otherwise value is not used
final Booleanuse_mutrue= true, if mu_a/mu_b are used in function, otherwise value is not used
final Booleanuse_Re_turbulenttrue= true, if Re_turbulent input is used in function, otherwise value is not used
final Booleanuse_roughnesstrue= true, if roughness is used in function, otherwise value is not used

Function 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 Modelica.​Fluid.​Pipes.​BaseClasses.​WallFriction.​PartialWallFriction.​massFlowRate_dp (Return mass flow rate m_flow as function of pressure loss dp, i.e., m_flow = f(dp), due to wall friction).

Inputs

TypeNameDescription
PressuredpPressure loss (dp = port_a.p - port_b.p)
Densityrho_aDensity at port_a
Densityrho_bDensity at port_b
DynamicViscositymu_aDynamic viscosity at port_a (dummy if use_mu = false)
DynamicViscositymu_bDynamic viscosity at port_b (dummy if use_mu = false)
LengthlengthLength of pipe
DiameterdiameterInner (hydraulic) diameter of pipe
AreacrossAreaInner cross section area
RoughnessroughnessAbsolute roughness of pipe, with a default for a smooth steel pipe (dummy if use_roughness = false)
AbsolutePressuredp_smallRegularization of zero flow if |dp| < dp_small (dummy if use_dp_small = false)
ReynoldsNumberRe_turbulentTurbulent flow if Re >= Re_turbulent (dummy if use_Re_turbulent = false)

Outputs

TypeNameDescription
MassFlowRatem_flowMass flow rate from port_a to port_b

Function 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 Modelica.​Fluid.​Pipes.​BaseClasses.​WallFriction.​PartialWallFriction.​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).

Inputs

TypeNameDescription
PressuredpPressure loss (dp = port_a.p - port_b.p)
Densityrho_aDensity at port_a
Densityrho_bDensity at port_b
DynamicViscositymu_aDynamic viscosity at port_a (dummy if use_mu = false)
DynamicViscositymu_bDynamic viscosity at port_b (dummy if use_mu = false)
LengthlengthLength of pipe
DiameterdiameterInner (hydraulic) diameter of pipe
Realg_times_height_abGravity times (Height(port_b) - Height(port_a))
AreacrossAreaInner cross section area
RoughnessroughnessAbsolute roughness of pipe, with a default for a smooth steel pipe (dummy if use_roughness = false)
AbsolutePressuredp_smallRegularization of zero flow if |dp| < dp_small (dummy if use_dp_small = false)
ReynoldsNumberRe_turbulentTurbulent flow if Re >= Re_turbulent (dummy if use_Re_turbulent = false)

Outputs

TypeNameDescription
MassFlowRatem_flowMass flow rate from port_a to port_b

Function 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 Modelica.​Fluid.​Pipes.​BaseClasses.​WallFriction.​PartialWallFriction.​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).

Inputs

TypeNameDescription
MassFlowRatem_flowMass flow rate from port_a to port_b
Densityrho_aDensity at port_a
Densityrho_bDensity at port_b
DynamicViscositymu_aDynamic viscosity at port_a (dummy if use_mu = false)
DynamicViscositymu_bDynamic viscosity at port_b (dummy if use_mu = false)
LengthlengthLength of pipe
DiameterdiameterInner (hydraulic) diameter of pipe
AreacrossAreaInner cross section area
RoughnessroughnessAbsolute roughness of pipe, with a default for a smooth steel pipe (dummy if use_roughness = false)
MassFlowRatem_flow_smallRegularization of zero flow if |m_flow| < m_flow_small (dummy if use_m_flow_small = false)
ReynoldsNumberRe_turbulentTurbulent flow if Re >= Re_turbulent (dummy if use_Re_turbulent = false)

Outputs

TypeNameDescription
PressuredpPressure loss (dp = port_a.p - port_b.p)

Function 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 Modelica.​Fluid.​Pipes.​BaseClasses.​WallFriction.​PartialWallFriction.​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).

Inputs

TypeNameDescription
MassFlowRatem_flowMass flow rate from port_a to port_b
Densityrho_aDensity at port_a
Densityrho_bDensity at port_b
DynamicViscositymu_aDynamic viscosity at port_a (dummy if use_mu = false)
DynamicViscositymu_bDynamic viscosity at port_b (dummy if use_mu = false)
LengthlengthLength of pipe
DiameterdiameterInner (hydraulic) diameter of pipe
Realg_times_height_abGravity times (Height(port_b) - Height(port_a))
AreacrossAreaInner cross section area
RoughnessroughnessAbsolute roughness of pipe, with a default for a smooth steel pipe (dummy if use_roughness = false)
MassFlowRatem_flow_smallRegularization of zero flow if |m_flow| < m_flow_small (dummy if use_m_flow_small = false)
ReynoldsNumberRe_turbulentTurbulent flow if Re >= Re_turbulent (dummy if use_Re_turbulent = false)

Outputs

TypeNameDescription
PressuredpPressure loss (dp = port_a.p - port_b.p)