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CoSimIO

Small standalone tool for interprocess communication in CoSimulation contexts for coupling and exchanging data between different solvers or other software-tools.

Documentation of the CoSimIO

Table of Contents

Welcome to the documentation of CoSimIO.

Structure of CoSimIO and which part it plays in Kratos CoSimulation

Even though the CoSimIO is a standalone tool, it reaches its full capabilities only in combination with the CoSimulation features of Kratos. It is implemented as detached interface. This section explains how everything fits together.

Kratos CoSimulation Library Overview

Conceptually the Kratos CoSimulation consists of 3 main components:

  1. Data Transfer: Any co-simulation process needs several data communications between different solvers/executables and Kratos. This includes raw data (in the form of vectors), meshes, and mesh data (like nodal and elemental data) or control signals. So a flexible data transfer mechanism one of the important components of the library.
  2. Coupling Solutions: Coupling algorithms have many common parts like the strategy, convergence criteria, convergence accelerators, and predictors. To be seamlessly usable in Kratos such an algorithm should provide the same interface as internal solutions of Kratos. The Kratos CoSimulation provides many of these tools and algorithms generic enough to be used in different contexts.
  3. Mapping Between Meshes: In many coupling problems the mesh in each domain is done considering the special requirements of that domain (like fluid, structure, etc.). This means that in those cases the meshes are not conformant between does domains and we should map our data from one to the other. Depending on the type of the coupling this may happen over some surfaces or volumes of the model. Kratos CoSimulation also provides this capability.

Based on these concepts these are the main components of the library:

  1. CoSimIO: This library is in charge of the data transfer between different programs using interprocess communication.
  2. CoSimulationApplication: This is an application of Kratos which is located in kratos/applications/CoSimulationApplication folder in the Kratos repository. This application provides a generic coupled solver with several convergence criteria, convergence accelerators, and predictors. Check the link for a more detailed overview.
  3. MappingApplication: The standard mapping application of the Kratos located in kratos/applications/MappingApplication folder. This application provides the mapping of data from one mesh to another one. It supports the 1D, 2D and 3D mapping with different types of mappings (like nearest node, nearest element, etc.). Check the link for a more detailed overview.

Kratos provides an extensive Python interface to its CoSimulation library which is used in the tutorials.

Tutorials for integrating the CoSimIO

The tutorials can be found here.

API documentation

The documentation for the API of the CoSimIO can be found here.

Communication

The available methods for (interprocess) communication are explained here.

Kratos CoSimulation

For using the CoSimIO with Kratos it is necessary to build Kratos (separately). Basic explanations are given here with links for more detailed descriptions.

Miscellaneous