Numerical modelling of the interaction between water sprays and hot air jets - Part II: Two-phase flow simulations

Abstract

The paper presents a comprehensive set of numerical simulations performed to examine the current Computational Fluid Dynamics (CFD) capabilities in the prediction of the interaction of a water mist spray with a vertical upward jet of hot air within an Eulerian-Lagrangian framework. The experimental tests

A review on fire suppression by fire sprinklers

“…The study identifies the momentum ratio of hot air to spray, droplet size variation and volume flux due to water evaporation as key parameters that define plume-spray interaction. Similarly, Beji et al 48 also reported a reduction in the maximum ceiling jet velocity by 50%, while increase in ceiling layer thickness observed was also four times for the vertical jet-dominated spray regimes. The three regimes of spray-jet interaction (i.e.…”

Experimental and numerical study on the interaction of a water mist spray with a turbulent buoyant flame

“…The settings for the base case are reported in Table 3. The initial velocity was calculated as: (7) where ρd is the water density (1000 kg/m 3 ) and ΔPw is the operational pressure of the nozzle. The constant C accounts for friction losses in the nozzle, estimated as C = 0.95.…”

“…Therefore, Computational Fluid Dynamics (CFD) simulations are a very useful 'support' tool in this context. In [6] and [7], e.g., the influence of a water mist spray on the ceiling-jet underneath a horizontal ceiling plate, created by a vertical upward jet of hot air, was reproduced very well. In [8], it has been reported that the heat release rate (HRR) instantaneously increased by the water mist flow just before rapidly decreasing because the high-speed water mist jet flow pushed the fuel vapor to the side.…”

LES Study of a Turbulent Spray Jet: Mesh Sensitivity, Mesh-Parcels Interaction and Injection Methodology

“…As an alternative, Computational Fluid Dynamics (CFD) codes have become important tool during the past decades, due to the increasing computional resources and due to the development of scalable CFD solvers (e.g, OpenFOAM R 2.4.0 [26] used in this study). Furthermore, the need for accurate simulation results of turbulent two-phase, dispersed flows, that can capture the complexity of the flow field within acceptable computational costs, has led to a significant interest in Large Eddy Simulations (LES) [16], [1], [14], [11].…”