Computational Fluid Dynamics (CFD)

INTRODUCTION

Computational Fluid Dynamics (CFD) simulations are essential tools in modelling hazardous events like fires, explosions, and toxic releases. By solving complex equations that describe fluid flow, heat transfer, and chemical reactions, CFD provides detailed insights into how these events unfold. This information is crucial for understanding the behaviour of hazardous materials such as Hydrocarbons, Hydrogen, Ammonia, CO2, NOx, etc. and predicting their impact on the environment and human health.

APPLICATIONS OF CFD IN HAZARDOUS EVENT MODELLING

Fires

CFD can simulate different types of fires such as jet fires and pool fires with their associated heat and duration, as well as the spread of smoke. CFD is helping to design effective gas detection systems, fire suppression systems and evacuation plans.

Explosions

CFD models can model explosions in confined and unconfined areas (e.g vapour cloud explosions – VCEs), predict blast wave propagation and structural damage, aiding in the development of safer building designs and protective measures.

Releases of hazardous fluids

CFD simulations can model the dispersion of harmful substances in the air or water (e.g., subsea releases), enabling authorities to implement timely and effective response strategies. CFD can reveal the presence of accumulation zones where hazardous gas accumulates despite the presence of ventilation.

BENEFITS OF CFD

Integrating CFD simulations into Quantitative Risk Assessments (QRA) enhances the accuracy and reliability of risk evaluations. By providing a detailed, scenario-specific analysis, CFD helps identify potential hazards, assess their likelihood, and evaluate the effectiveness of mitigation measures. This comprehensive approach supports informed decision-making, ensuring that safety measures are both effective and efficient, ultimately protecting lives and property.’

CFD is often a tool of choice to support the decision-making process, especially in situations where the consequences of a hazardous event are difficult to predict with engineering judgement or simpler models, but foreseen to be potentially severe. CFD simulations would in these cases help reaching a consensus between the project stakeholders.

CFD software are powerful tools which can perform thousands of different scenarios in a few hours and allows for flexibility. The 3D models used in the simulations and the parameters defining the scenario (e.g., fluid composition, wind conditions, ignition location) can be easily adjusted to reflect the latest configuration of your plant, process or equipment and enables performing sensitivity calculations.

CFD modelling yet requires expertise in order to generate accurate and credible scenario.  Although most of the CFD software available today are robust and can generate results whatever the inputs are, one must be careful with the interpretation of the results. A scenario wrongly set-up, a poor quality of the mesh/grid, may lead to under- or over-estimating the outcomes of a hazardous event (e.g., too low fire radiation or explosion pressures) and will lead to incorrect conclusions. Hence it is recommended to seek support from competent personnel to perform the work.

OUR EXPERTISE IN CFD

ORS has worked with numerous projects involving CFD studies and our experts will be able to support you in your request. Please feel free to reach out in case you would like to discuss more about our CFD services.