modelDragForce
Vehicle rolling and aerodinamical drag force
Extends from Modelica.Mechanics.Translational.Interfaces.PartialElementaryOneFlangeAndSupport2 (Partial model for a component with one translational 1-dim. shaft flange and a support used for textual modeling, i.e., for elementary models), Modelica.Mechanics.Translational.Interfaces.PartialFriction (Base model of Coulomb friction elements).
Information
This component models the total (rolling and aerodynamic) vehicle drag resistance:
F=fc*m*g+(1/2)*rho*Cx*S*v^2
It models reliably the stuck phase. Based on Modelica-Intrerfaces.PartialFriction model
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | useSupport (from PartialElementaryOneFlangeAndSupport2) | false | = true, if support flange enabled, otherwise implicitly grounded |
| Integer | Unknown (from PartialFriction) | 3 | Value of mode is not known |
| Integer | Free (from PartialFriction) | 2 | Element is not active |
| Integer | Forward (from PartialFriction) | 1 | v_relfric > 0 (forward sliding) |
| Integer | Stuck (from PartialFriction) | 0 | v_relfric = 0 (forward sliding, locked or backward sliding) |
| Integer | Backward (from PartialFriction) | -1 | v_relfric < 0 (backward sliding) |
| Modelica.Units.SI.Mass | m | vehicle mass | |
| Modelica.Units.SI.Density | rho | 1.226 | air density |
| Modelica.Units.SI.Area | S | vehicle cross area | |
| Real | fc | rolling friction coefficient | |
| Real | Cx | aerodinamic drag coefficient | |
| Advanced | |||
| SI.Velocity | v_small (from PartialFriction) | 1e-3 | Relative velocity near to zero (see model info text) |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Flange_b | flange (from PartialElementaryOneFlangeAndSupport2) | Flange of component | |
| Support | support (from PartialElementaryOneFlangeAndSupport2) | Support/housing of component |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Length | s (from PartialElementaryOneFlangeAndSupport2) | Distance between flange and support (= flange.s - support.s) | |
| SI.Velocity | v_relfric (from PartialFriction) | Relative velocity between frictional surfaces | |
| SI.Acceleration | a_relfric (from PartialFriction) | Relative acceleration between frictional surfaces | |
| SI.Force | f0 (from PartialFriction) | Friction force for v_relfric=0 and forward sliding | |
| SI.Force | f0_max (from PartialFriction) | Maximum friction force for v_relfric=0 and locked | |
| Boolean | free (from PartialFriction) | = true, if frictional element is not active | |
| Real | sa (from PartialFriction) | Path parameter of friction characteristic f = f(a_relfric) | |
| Boolean | startForward (from PartialFriction) | = true, if v_relfric=0 and start of forward sliding | |
| Boolean | startBackward (from PartialFriction) | = true, if v_relfric=0 and start of backward sliding | |
| Boolean | locked (from PartialFriction) | = true, if v_relfric=0 and not sliding | |
| Integer | mode (from PartialFriction) | Mode of friction (-1: backward sliding, 0: stuck, 1: forward sliding, 2: inactive, 3: unknown) | |
| Modelica.Units.SI.Force | f | Total drag force | |
| Modelica.Units.SI.Velocity | v | vehicle velocity | |
| Modelica.Units.SI.Acceleration | a | Absolute acceleration of flange | |
| Real | Sign |