Modeling of Spray-Induced Wall Stress on a Hot Surface of Ignition Assistance Device

Abstract

This study proposes a new wall-stress model, named ARL Spray-Impacted Wall Stress model (ARL-SIWS), which directly integrates the impact from the spray-induced mechanical stress on the solid wall component. Proposed modeling workflow can be readily incorporated into existing Lagrangian spray-wall interaction models and enable to calculate the impulse from the impinging particles. The first primary focus of this paper embraces the model description and performance evaluation. The proposed model was validated against the experimentally available impinging spray-jet impulse data across the diesel engine relevant conditions. The remaining part of the content brings more practical aspect of using the model in the application of ignition assistance (IA) device, which is designed for ignition enhancement of jet-fuel in aircraft propulsion systems. In this type of ignition enhancement strategy such as glow-plug systems, mechanical stress level arising on the hot surface element becomes significant and possibly raise a serious concern of system durability. Former studies have dealt with this topic solely concerning the interaction between continuous phase of fluid element and solid wall component. The proposed ARL-SIWS model in this study allows to add additional impact contributed by the impinging spray momentum. The simulated stress distribution on the IA device component can thus be well understood in terms of the source of stress such as gas pressure-induced term and spray-induced term. Thereby, the proposed strategy put forth the usage of the ARL-SIWS model in the follow-up system durability analysis.