Download PDF Process and Plant Safety Applying Computational Fluid Dynamics by Jürgen Schmidt

Sinopsis

Safety engineering is based on reliable and conservative calculations. With Computational Fluid Dynamics (CFD) tools, the knowledge of certain physical processes is deepened significantly. However, such programs are currently not standard. In safety engineering more stringent demands for accuracy must be set, for example, as compared to methods for the optimization of plants. The methods must, among other things, be sufficiently validated by experiences or experimental data and fully documented (method transparency). In addition, they must be comprehensible, reproducible, and economical to apply. The necessary demands on precision can usually only be met by model developers, program suppliers, and users of the CFD codes (common sense application).

The developers ofmodelsmust document theirmodels, and the assumptionsunder which the models were derived must be fully understandable. Only if the application range is carefully described can a responsible transfer to other fluids and parameter rages take place at some later time. Unlike simple empirical correlations,CFD models, with theirmany sub-models, often appear complex and not transparent. Thevalidation is usually done only on certain individual data points or by measuring global parameters such as pressures and mass flows. This makes it difficult to assess whether a method is more generally applicable in practice. Margins of error cannot be estimated, or only very roughly. There are relatively for model validations for typical questions in the field of safety engineering. However, even there only models and methods with sufficiently well-known uncertainties should be applied.

It is still not enough if only the model application ranges are transparent. In addition it should be possible to review the CFD program codes. Most codes are not currently open source. Moreover, frequent version changes and changes in the program codes complicate any review. Generally accepted example calculations which can be used for revalidation (safety-relevant test cases) are usually lacking. There are often demands for open-source programs among the safety experts. This certainly facilitates the testing of models. On the other hand, in practice it is then only barely comprehensible what changes were made in a program in any particular case.

CFD calculations are reasonably possible in safety technology only with a good education and disciplined documentation of the results.

Content

1. Computational Fluid Dynamics: the future in safety technology!
2. Organized by ProcessNet: Tutzing Symposion 2011 CFD – its Future in Safety Technology
3. CFD and Holistic Methods for Explosive Safety and Risk Analysis
4. Status and Potentials of CFD in Safety Analyses Using the Example of Nuclear Power
5. Sizing and Operation of High-Pressure Safety Valves
6. Water Hammer Induced by Fast-Acting Valves – Experimental Studies, 1D Modeling, and Demands for Possible Future CFX Calculations
7. CFD-Modeling for Optimizing the Function of Low-Pressure Valves
8. Consequences of Pool Fires to LNG Ship Cargo tanks
9. CFD Simulation of Large Hydrocarbon and Peroxide Pool Fires
10. Modeling Fire Scenarios and Smoke Migration in Structures
11. The ERCOFTAC Knowledge Base Wiki – An Aid for Validating CFD Models
12. CFD at its Limits: Scaling Issues, Uncertain Data, and the User’s Role
13. Validation of CFD Models for the Prediction of Gas Dispersion in Urban and Industrial Environments
14. CFD Methods in Safety Technology – Useful Tools or Useless Toys?
15. Dynamic Modeling of Disturbances in Distillation Columns
16. Dynamic Process Simulation for the Evaluation of Upset Conditions in Chemical Plants in the Process Industry
17. The Process Safety Toolbox – The Importance of Method Selection for Safety-Relevant Calculations
18. CFD for Reconstruction of the Buncefield Incident
19. Do We Really Want to Calculate the Wrong Problem as Exactly as Possible? The Relevance of Initial and Boundary Conditions in Treating the Consequences of Accidents
20. Can Software Ever be Safe?
21. CFD Modeling: Are Experiments Superfluous?

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