Computational Modeling of Accidental Fire Spread in Under-Ventilated Compartments

The reliable prediction of fires in under-ventilated compartment environments is critical to the design against and mitigation of accidental engine fires. Of specific concern in aviation gas turbines is the ignition and spread of fires arising in the fan case compartment due to the potential for leakage from pressurized fuel or hydraulic fluid lines and the presence of ignition sources in the form of hot surfaces. This presentation will describe recent efforts toward the analysis and development of modeling capabilities for the prediction of such compartment fires. By considering specific operating environments pertaining to aircraft flight conditions, relevant physical mechanisms will be reviewed, which include liquid fuel injection, evaporation, wall filming, ignition, and flame/wall coupling. A test case will be presented that captures the relevant physical processes, and results will be discussed which consider the ignition and fire-spread arising from the forced ignition of liquid kerosene fuel at low-pressure conditions in an under-ventilated environment.