.Modelica.Mechanics.MultiBody.Examples.Loops.EngineV6_analytic

Information

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.