Critical review of Molkov's phenomenological model and variable stretch/turbulence function

F. Hernandez, M. Abdel-Jawad, Hong Hao

    Research output: Contribution to journalArticle

    Abstract

    © 2016 Elsevier Ltd. A critical review of Molkov's phenomenological model including the model's assumptions and sub-models is presented in this article. First, the effect of an incorrect discharge sub-model is studied and it is concluded that the choice of discharge sub-model is crucial because it can substantially modify the turbulence/stretch function, the mass distributions and the flame position. Therefore, a discharge sub-model should only be chosen when the sub-model is in agreement with the flame position and the residual unburnt gas mass reaches a reasonable value. Second, the equivalent flame radius and the apparent flame velocity (computed internally by Molkov's model) are found to depend on three different effects: the free flameball expansion, the adiabatic compression/extension and the venting process. Third, the interpretation of the turbulence function should account for the effect of the propagation mode and the spatial variation of the local flame speed. Fourth, the jet effect model related to hinge panels can be improved; therefore, a new model is presented. Fifth, the universal correlation and the two-lumped-parameter model are studied. Despite the high correlation reported in previous publications, it is concluded that the two-lumped-model has significant limitations and should be improved if a variable stretch/turbulence function is utilized, which will require the utilization of "usual" discharge coefficients. Finally, it is shown that the inverse problem with a variable stretch/turbulence function and a reasonable discharge coefficient can be utilized to accurately backfit experimental data.
    Original languageEnglish
    Pages (from-to)225-241
    JournalJournal of Loss Prevention in the Process Industries
    Volume43
    Early online date20 May 2016
    DOIs
    Publication statusPublished - Sep 2016

    Fingerprint Dive into the research topics of 'Critical review of Molkov's phenomenological model and variable stretch/turbulence function'. Together they form a unique fingerprint.

  • Cite this