The transport of water sprays past generic clutter elements found within engine nacelles

The current work is presented as part of an effort to develop a spray transport model that would be used within the computational fire code currently under development by Sandia National Laboratory. As part of a halon replacement research program, new high-boiling-point chemical suppressants have been identified. These agents would discharge in a liquid state and initially result in the transport of liquid droplets through a portion of the nacelle, impinging on various objects prior to reaching the fire zone. The goal of this research effort is to enhance the fundamental knowledge of spray interactions with clutter (e.g., obstacles representing fuel and hydraulic lines, electrical wire bundles, etc). This paper reports on an experimental investigation into the effect of generic cylindrical clutter elements on the performance of a suppressant spray impinging on various clutter densities and porosities. Specifically the amount of agent (water/air spray) that is transported through a generic clutter configuration is presented as a function of clutter spacing and surrounding air. The air coflow speed was set between 0.5 and 6.5 m/s at nominal turbulence levels of 10%.