Entwicklung eines Multiphysic-Modells für eine schaltbare elektrische Entladung zur Vorhersage der Explosionswahrscheinlichkeit von entflammbaren Gasen
Elektrotechnik und Informationstechnik
The objective of this project is the development of an experimentally verified multi-physical model of an electrical discharge for applying practical and reproducible test procedures for predicting explosions in flammable gas mixtures. For this purpose, the safety-critical situations and effects under specified conditions have to be identified, investigated using a specially developed experimental setup and analyzed. Emphasis will be placed on understanding the physical processes, which dominate the ignition of spark discharges and finally the ignition of the explosion under the specific condition of minimum
ignition energy. A detailed understanding of different discharge phenomena from pre discharges towards the main spark discharge, of the electrode erosion responsible for the discharge medium, of the energy balance of the main discharge including electrode and radiation losses, and of the final
energy deposition for the ignition of the thermo-chemical explosion process is aimed (see Fig. 2). In addition, the electric circuit parameters limiting the discharge behavior have to be evaluated as critical conditions. Based on the experimentally deduced conditions, a non-equilibrium plasma model of the main discharge as weil as an appropriate cathode sheath model should be developed, which should show the interplay of the different mechanisms. Finally, the inclusion of the plasma models and appropriate relations for the electrical boundary conditions into an existing thermo-chemical model of the explosion process should provide an overall theoretical description of safety-critical situations. This comprehensive model will serve as the basis for developing a better scientific understanding of explosion safety as weil as a globally applicable alternative to current test methods.