TOOLS AND TECHNIQUES FOR MULTIDISCIPLINARY COUPLED SIMULATIONS

ABSTRACT This paper describes three kinds of tools for supporting multidisciplinary coupled simulations: A coupling library for data exchange and mesh interpolation, a script interpreter for controlling the coupled computation, and an integration system for graphical setup and start of coupled simulations in distributed environments. A tool for enabling stand-alone applications to be used in a multidisciplinary coupled simulation is the MpCCI library. It is integrated into various simulation codes and handles the data exchange and interpolation between the meshes of the codes. An add-on to the library has been developed to use a Python script for controlling the coupled simulation, i.e. for implementing coupling algorithms. As a mean to simplify the error prone task of setting-up and executing multidisciplinary, coupled simulations the TENT system is presented. 1. INTRODUCTION This paper describes software tools and libraries which can be employed to help the users in performing coupled simulation. It focuses on the usage of such tools in the simulation environment TENT. TENT is a component-based software integration environment and workflow management system. It is used to integrate the applications for building complex workflows which are typical for multidisciplinary simulations in engineering and scientific applications where simulation codes have to be coupled to obtain reliable results. TENT provides means to simplify the error prone task of setting-up and executing multidisciplinary, coupled simulations. Software development techniques based on modern software products like powerful scripting languages, e.g. Python, portable implementation of basic system parts by using Java, and encapsulation of data and task using an component-based approach relying on CORBA for the interaction of the components are employed for the implementation. TENT has been developed to aid users in setting up and steering scientific workflows in distributed, non-homogeneous hardware environments. Typically, a workflow consists of simulation codes, pre- and post-processing tools, and visualisation programmes. In addition, a data server is available to store and reload simulation and configuration data. The applications of the workflow are control via TENT components which communicate with the integration system by standardised CORBA interfaces and with the application code using a socket connection. The data transfer between two applications is managed by the associated components in a peer-to-peer manner. To support coupled computations that are using the MpCCI library for interpolation and data transfer between codes a special TENT component has been developed. This component handles the start-up of the computation and creates the files necessary to run an MpCCI-job using information supplied by the components of the coupled applications. To integrate proprietary or commercial software into the system,