(102b) Jet Flame Length and Thermal Radiation: Evaluation with CFD Simulations

Thermal hazard resulting from jet flames in chemical processes can be a significant contributor to risk onsite. It is beneficial to understand and predict its characteristics with reasonable accuracy. A review of various models typically used in process safety applications showed that most models were developed based on vertical jet flames, but are applied to horizontal jet flames. This generally results in over-predicting the flame length and distances to thermal radiation thresholds of interest in process safety applications, because it incorrectly accounts for buoyancy by predicting longer horizontal distances rather than upward curvature. Predictions from a range of representative models were compared with detailed analysis of jet flame through Computational Fluid Dynamics (CFD) simulations and also compared with an actual test. Preliminary results show that models tested and CFD predictions are reasonably consistent for small releases. However, for large releases, the models tested over-predict the CFD results of flame dimensions and thermal radiation distances. This paper discusses weaknesses and strengths of various models compared to CFD simulations. BakerRisk has a comprehensive test program in progress to validate and refine the CFD simulation approach and define a more representative thermal hazard prediction model.