Cloud computing replaces large upfront expenses with low, variable payments that only apply to what you use. CFD simulations cover a range of sizes and complexity. Activity is generally interrupted by quiet periods when simulations are halted, e.g. when a simulation ends non-working hours, during analysis of results or preparation of a new simulation, etc. The fluctuating demand makes CFD well suited to a pay-per-use model. Users need to understand the costs involved to get the best value from cloud and be confident that they fall within budget. This article explains the costs, with an example of an external aerodynamics calculation with OpenFOAM using CFD Direct From the Cloud™ (CFDDFC) on Amazon Web Services (AWS).
A breakdown of outstanding issues in OpenFOAM (2016-10-26) shows 90% of unresolved issues falling within only 7 categories. The two worst offenders account for almost half of all unresolved issues: 1) AMI, ACMI and cyclic interfaces; and, 2) heat transfer, including conjugate heat transfer (CHT). These categories, and “particles and tracking” and “sources/constraints” in particular, require significant refactoring and/or rewriting. Their current state of disrepair was caused by poor funding under a roadmap development strategy. Funding of agile development of OpenFOAM is now needed to support our aim to improve quality, with a target 50% reduction in unresolved issues in 2017.
Agile development of OpenFOAM emerged following the public distribution of the development line in December 2014. It relies on user participation, which is encouraged by rewarding users for reporting issues with timely resolution. OpenFOAM was in poor health at version 2.3.0, with unresolved issues increasing rapidly and long resolution times. Following the move to agile development, unresolved issues are reduced and under control, with ~70% of issues resolved in 1 day and ~90% resolved in 1 week, taking OpenFOAM to a new level of quality and maturity (always releasable) by version 4.0.
The OpenFOAM Issue Tracking system exists to enable users to report issues. An issue exists when OpenFOAM behaves in a manner that does not meet reasonable expectations, including in design and usability. OpenFOAM is mature, quality software, whose successful development demands that issues are resolved in a timely manner. Roadmap development obstructs issue resolution, resulting in unreliable software and inefficient development. Instead, free, open source software can exploit agile development with frequent code release, as the best strategy for CFD development. Users should adopt continuous upgrade to minimize cost and to benefit the agile development strategy.
In January-July 2017, CFD Direct are running sessions of their OpenFOAM Training courses — Essential CFD, Applied CFD and Programming CFD — fully updated with the latest features of the new version 4 release of OpenFOAM: 31 Jan – 1 Feb 2017, Virtual Americas; 6-9 Feb 2017, London UK; 27 Feb – 2 Mar 2017, Houston USA; 21-22 Mar, Virtual Europe; 24-27 April 2017, Berlin Germany. OpenFOAM v4 contains new functionality we introduced in OpenFOAM v4 to improve usability so our course participants spend less time struggling with quirks of the software, leaving more time to build and practice their CFD skills.
CFD Tips is our YouTube channel containing a series of free instructional videos for computational fluid dynamics (CFD) with OpenFOAM. We started the channel in July 2016 and are adding new videos regularly. We aim to provide videos on all aspects of CFD practice, including geometry and meshing, fluid dynamics and modelling, numerics and data analysis. We will also provide videos on OpenFOAM programming, general computing and deployment locally and via the cloud.