: Co-Simulation Strategy
MpCCI Coupling Environment employs a staggered approach for all co-simulation problems which can be defined as
A globally explicit coupling method: the coupled fields are exchanged only once per coupling step. This solution is applicable to problems with weak physics coupling.
An implicit iterative coupling method: the coupled fields are exchanged several times per coupling step until an overall stabilized solution is achieved and before advancing to the next coupling step. This approach is applicable to problems with strong physics coupling.
MpCCI Coupling Environment offers standard coupling algorithms to implement the above coupling approaches - e.g. Gauss-Seidel and Jacobi.
Gauss-Seidel coupling scheme is also known as serial or "Ping-Pong" algorithm where one code waits while the partner code proceeds.
Jacobi coupling scheme is also known as parallel algorithm where both analysis codes run concurrently.
In addition to these coupling algorithms different transfer options are provided to control the data exchange of the quantities:
The data exchange can be defined as an optional or forced synchronization point. The optional synchronization point provides the alternative to activate the data exchange on request. This request can be triggered by the availability of the quantities or by a physical quantity criterion. This provides an adaptive coupling scheme where bi-directional and uni-directional data transfer can be mixed.
The synchronization point can be defined at different coupling iteration step for a steady state solution, or at different coupling time step sizes for a transient solution. The coupling iteration step, resp. coupling time step size may differ from the solver iteration step, resp. time step size. By this way a sub-cycling has been added to the coupling algorithm.