OpenFOAM: Object-Oriented Software in Computational Continuum Mechanics

Dr. Hrvoje Jasak (The Cavendish Laboratory, University of Cambridge) Cambridge Fluids Network - fluids-related seminars 25 February 2022 12:30pm CUED, LT6 Increasing computing power and established numerical modelling techniques drive the numerical modelling in continuum mechanics beyond the basics of structural analysisand fluid flow. Software implementation of complex and coupled physical poses challenges beyond the current generation of simulation tools. A new, flexible and efficient model implementation framework is needed. One possible answer is object orientation. OpenFOAM (Field Operation And Manipulation) is an open source object-oriented numerical simulation library aimed at complex physics modelling and will be described in this seminar. OpenFOAM handles continuum models by mimicking partial differential equations in software. Polyhedral Finite Volume discretisation is implemented in operator form (e.g. temporal derivatives, gradient, divergence, source and sink terms), and operators are combined to form equations. Efficiency and elegance in implementation is achieved through layered development and extensive code re-use, where various components (e.g. mesh handling, field algebra and calculus, discretisation, linear algebra and solvers, dynamic meshing etc.) are developed and validated in isolation. Auxiliary tools support the basic solvers, providing pre- and post-processing interfaces, dynamic mesh handling, real material properties, massive parallelism, Lagrangian particle model and other tools present in a modern CFD solver. The library is completed with a suite of physical models, covering incompressible, compressible, multi-phase and free surface fluid flow, a suite of 30 RANS and LES turbulence models, combustion, spray and in-cylinder simulations, structural analysis, electromagnetics and fluid-structure interaction. Today, OpenFOAM is a leading Open Source CFD tool, rapidly expanding in the research community and among industrial users. The talk will be completed with examples of application of OpenFOAM in fluid flow and structural analysis and a review of contributing organisations, active research areas and future development plans.