The overall objective of this research is to gain fundamental knowledge of fire-suppression agent transport in the cluttered environments of aircraft engine nacelles (i.e., hydraulic and electrical lines, mounting brackets, etc.). A new generation of Halon replacements includes chemical suppressants with high boiling-points that will exist in a liquid phase at discharge. The release of these agents in confined spaces may result in impact of droplets with nearby solid surfaces and inhibit the effectiveness of the agent. The focus of the current effort is to develop a model to account for these effects into a Lagrangian modeling framework for spray transport. The impact model is formulated using mass and energy conservation principles along with established empirical correlations for breakup of individual droplets. Results are presented for 1 mm in diameter HFE-7100 liquid droplets impacting into a circular cylinder for several velocities spanning the impact regimes of droplet adhesion, bouncing and breakup.
Citation: A Droplet Impact Model for Agent Transport in Engine Nacelles
Pub Type: Others
computational fluid dynamics, droplet/particle transport, fire suppression, halon alternatives, homogeneous turbulent flow, model validation, particle image velocimetry