Pipe wall friction for laminar and turbulent flow (detailed characteristic)
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.
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.
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.
Extends from PartialWallFriction (Partial wall friction characteristic (base package of all wall friction characteristics)).
| Name | Description |
|---|---|
 massFlowRate_dp
|
Return mass flow rate m_flow as function of pressure loss dp, i.e., m_flow = f(dp), due to wall friction |
| 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 |
| 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 |
| 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 |
 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_dpReturn mass flow rate m_flow as function of pressure loss dp, i.e., m_flow = f(dp), due to wall friction
Extends from (Return mass flow rate m_flow as function of pressure loss dp, i.e., m_flow = f(dp), due to wall friction).
| Name | Description |
|---|---|
| dp | Pressure loss (dp = port_a.p - port_b.p) [Pa] |
| rho_a | Density at port_a [kg/m3] |
| rho_b | Density at port_b [kg/m3] |
| mu_a | Dynamic viscosity at port_a (dummy if use_mu = false) [Pa.s] |
| mu_b | Dynamic viscosity at port_b (dummy if use_mu = false) [Pa.s] |
| length | Length of pipe [m] |
| diameter | Inner (hydraulic) diameter of pipe [m] |
| crossArea | Inner cross section area [m2] |
| roughness | Absolute roughness of pipe, with a default for a smooth steel pipe (dummy if use_roughness = false) [m] |
| dp_small | Regularization of zero flow if |dp| < dp_small (dummy if use_dp_small = false) [Pa] |
| Re_turbulent | Turbulent flow if Re >= Re_turbulent (dummy if use_Re_turbulent = false) [1] |
| Name | Description |
|---|---|
| m_flow | Mass flow rate from port_a to port_b [kg/s] |
Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.pressureLoss_m_flowReturn pressure loss dp as function of mass flow rate m_flow, i.e., dp = f(m_flow), due to wall friction
Extends from (Return pressure loss dp as function of mass flow rate m_flow, i.e., dp = f(m_flow), due to wall friction).
| Name | Description |
|---|---|
| m_flow | Mass flow rate from port_a to port_b [kg/s] |
| rho_a | Density at port_a [kg/m3] |
| rho_b | Density at port_b [kg/m3] |
| mu_a | Dynamic viscosity at port_a (dummy if use_mu = false) [Pa.s] |
| mu_b | Dynamic viscosity at port_b (dummy if use_mu = false) [Pa.s] |
| length | Length of pipe [m] |
| diameter | Inner (hydraulic) diameter of pipe [m] |
| crossArea | Inner cross section area [m2] |
| roughness | Absolute roughness of pipe, with a default for a smooth steel pipe (dummy if use_roughness = false) [m] |
| m_flow_small | Regularization of zero flow if |m_flow| < m_flow_small (dummy if use_m_flow_small = false) [kg/s] |
| Re_turbulent | Turbulent flow if Re >= Re_turbulent (dummy if use_Re_turbulent = false) [1] |
| Name | Description |
|---|---|
| dp | Pressure loss (dp = port_a.p - port_b.p) [Pa] |
Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.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
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).
| Name | Description |
|---|---|
| dp | Pressure loss (dp = port_a.p - port_b.p) [Pa] |
| rho_a | Density at port_a [kg/m3] |
| rho_b | Density at port_b [kg/m3] |
| mu_a | Dynamic viscosity at port_a (dummy if use_mu = false) [Pa.s] |
| mu_b | Dynamic viscosity at port_b (dummy if use_mu = false) [Pa.s] |
| length | Length of pipe [m] |
| diameter | Inner (hydraulic) diameter of pipe [m] |
| g_times_height_ab | Gravity times (Height(port_b) - Height(port_a)) [m2/s2] |
| crossArea | Inner cross section area [m2] |
| roughness | Absolute roughness of pipe, with a default for a smooth steel pipe (dummy if use_roughness = false) [m] |
| dp_small | Regularization of zero flow if |dp| < dp_small (dummy if use_dp_small = false) [Pa] |
| Re_turbulent | Turbulent flow if Re >= Re_turbulent (dummy if use_Re_turbulent = false) [1] |
| Name | Description |
|---|---|
| m_flow | Mass flow rate from port_a to port_b [kg/s] |
Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.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
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).
| Name | Description |
|---|---|
| m_flow | Mass flow rate from port_a to port_b [kg/s] |
| rho_a | Density at port_a [kg/m3] |
| rho_b | Density at port_b [kg/m3] |
| mu_a | Dynamic viscosity at port_a (dummy if use_mu = false) [Pa.s] |
| mu_b | Dynamic viscosity at port_b (dummy if use_mu = false) [Pa.s] |
| length | Length of pipe [m] |
| diameter | Inner (hydraulic) diameter of pipe [m] |
| g_times_height_ab | Gravity times (Height(port_b) - Height(port_a)) [m2/s2] |
| crossArea | Inner cross section area [m2] |
| roughness | Absolute roughness of pipe, with a default for a smooth steel pipe (dummy if use_roughness = false) [m] |
| m_flow_small | Regularization of zero flow if |m_flow| < m_flow_small (dummy if use_m_flow_small = false) [kg/s] |
| Re_turbulent | Turbulent flow if Re >= Re_turbulent (dummy if use_Re_turbulent = false) [1] |
| Name | Description |
|---|---|
| dp | Pressure loss (dp = port_a.p - port_b.p) [Pa] |