Simcenter Amesim What is open loop interface used for in Amesim ? Can I use meaningful constant values ?

Meaningful constant values can now be defined as default inputs of models intended for export. This greatly improves the “open-loop simulation” interface, used for validation, when non-null quantities, such as absolute temperatures or pressures, are expected at model inputs. These values also get stored in exported FMUs as default start values for model inputs. If more convenient, FMI importing tools may reuse them silently with a higher degree of confidence than with previous hard-coded zeros.

                                      Column view of start values for open loop interface

An example use case

A Simcenter Amesim user splits a clutch fading model into a mechanical part and a thermal part. He thus creates two distinct models, each one with an interface block.

                          Example of clutch fading model using open loop interface  

He validates them via open-loop simulations using meaningful start values for expected inputs. The two models are exported as 2.0 FMUs for co-simulation. They are imported into a third-party software and connected with each other.

                                               Final FMI based model for Coupled Simulation 

The third-party tool user only sets the final time and runs the simulation immediately. On top of FMUs’ default experiments, the default start values set by the Simcenter Amesim user are silently reused, with an increased confidence.

The main advantage with this feature is that initialization errors can be found early and troubleshooted.