MPI Associated Scalability of Open-Source CFD Codes for Oil Spill Assessment

Abstract

General-purpose CFD codes have recently become an increasingly discussed alternative to standardized, simplified and usually empirically calibrated specialized tools for pollution analyses. Commonly, CFD codes tend to provide physically more sensible results and can indicate the underlying cause for a given problem. Use for ecological problems, however, has usually been avoided due to the sizes of computational domains and inherent complexity of the calculations that need to be conducted. Adoption in recent years is mostly driven by significant improvements in computational capabilities and advancements related to code and communication optimizations. Unfortunately, due to substantial branching of codes and accompanying indispensable communication routines, especially in open-source community, performance and consequently applicability of codes, can vary significantly. This article aims to outline key limitations and quantify performance gains which can be obtained in a high-performance computing environment through the use of different communication protocols, when evaluating typical pollution problems such as oil spills. Obtained results indicate that savings of up to 40% in computational time can be achieved, depending on the code and message passing interface implementation for a problem in question, thus demonstrating the importance of communication protocols.