WOLFRAM SYSTEM MODELER

EngineV6_analytic

V6 engine with 6 cylinders, 6 planar loops, 1 degree-of-freedom and analytic handling of kinematic loops

Diagram

Wolfram Language

In[1]:=
SystemModel["Modelica.Mechanics.MultiBody.Examples.Loops.EngineV6_analytic"]
Out[1]:=

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

This is a similar model as the example "EngineV6". However, the cylinders have been built up with component Modelica.Mechanics.MultiBody.Joints.Assemblies.JointRRR that solves the non-linear system of equations in an aggregation of 3 revolution joints analytically and only one body is used that holds the total mass of the crank shaft:

This model is about 20 times faster as the EngineV6 example and no linear or non-linear system of equations occur. In contrast, the "EngineV6" example leads to 6 systems of nonlinear equations (every system has dimension = 5, with Evaluate=false and dimension=1 with Evaluate=true) and a linear system of equations of about 40. This shows the power of the analytic loop handling.

Simulate for 3 s with about 50000 output intervals, and plot the variables engineSpeed_rpm, engineTorque, and filteredEngineTorque. Note, the result file has a size of about 240 Mbyte in this case. The default setting of StopTime = 1.01 s (with the default setting of the tool for the number of output points), in order that (automatic) regression testing does not have to cope with a large result file.

Parameters (1)

animation

Value: true

Type: Boolean

Description: = true, if animation shall be enabled

Outputs (3)

engineSpeed_rpm

Default Value: Modelica.Units.Conversions.to_rpm(load.w)

Type: AngularVelocity_rpm (rev/min)

Description: Engine speed

engineTorque

Default Value: filter.u

Type: Torque (N⋅m)

Description: Torque generated by engine

filteredEngineTorque

Default Value: filter.y

Type: Torque (N⋅m)

Description: Filtered torque generated by engine

Components (6)

world

Type: World

Description: World coordinate system + gravity field + default animation definition

engine

Type: EngineV6_analytic

Description: V6 engine with analytic loop handling

load

Type: Inertia

Description: 1D-rotational component with inertia

load2

Type: QuadraticSpeedDependentTorque

Description: Quadratic dependency of torque versus speed

torqueSensor

Type: TorqueSensor

Description: Ideal sensor to measure the torque between two flanges (= flange_a.tau)

filter

Type: CriticalDamping

Description: Output the input signal filtered with an n-th order filter with critical damping