Design patterns for multiphysics modeling in Fortran 2003 and C++

Abstract

We present three new object-oriented software design patterns in Fortran 2003 and C++. These patterns integrate coupled differential equations, facilitating the flexible swapping of physical and numerical software abstractions at compile-time and runtime. The Semi-Discrete pattern supports the time advancement of a dynamical system encapsulated in a single abstract data type (ADT). The Puppeteer pattern combines ADTs into a multiphysics package, mediates interabstraction communications, and enables implicit marching even when nonlinear terms couple separate ADTs with private data. The Surrogate pattern emulates C++ forward references in Fortran 2003. After code demonstrations using the Lorenz equations, we provide architectural descriptions of our use of the new patterns in extending the Rouson et al. [2008a] Navier-Stokes solver to simulate multiphysics phenomena. We also describe the relationships between the new patterns and two previously developed architectural elements: the Strategy pattern of Gamma et al. [1995] and the template emulation technique of Akin [2003]. This report demonstrates how these patterns manage complexity by providing logical separation between individual physics models and the control logic that bridges between them. Additionally, it shows how language features such as operator overloading and automated memory management enable a clear mathematical notation for model bridging and system evolution.

Exploring Capabilities within ForTrilinos by Solving the 3D Burgers Equation

“…We have summarized many of them in publications on modern Fortran program design and construction for numerical applications [7,13,14,16].…”

Extended ForUML for Automatic Generation of UML Sequence Diagrams from Object-Oriented Fortran

“…Modern Fortran is intended to support complex software development efforts and to increase productivity, especially for scientific and engineering software, through the application of software engineering principles. Clearly, many scientists and software engineering researchers are interested in and use modern Fortran for building software [22][23][24][25][26]. Many current Fortran compiler vendors such as the Numerical Algorithm Group (NAG) [27], GNU Fortran [28], IBM XL Fortran [29], Cary [30], and Intel Fortran [31] have enhanced their compilers to support Modern Fortran.…”

Object-Oriented Techniques for Sparse Matrix Computations in Fortran 2003

“…Recent work by Rouson et al [2010a] describes the definition of new design patterns for multiphysics modeling and presents both a Fortran 2003 and a C++ approach to their implementation; sophisticated interfacing of Fortran 2003 with C/C++ is explored in Rouson et al [2010b].…”