Numerical studies on sprinkler-hot layer interaction

Wan Ki Chow, Y. L. Cheung

Research output: Journal article publicationJournal articleAcademic researchpeer-review

2 Citations (Scopus)

Abstract

This paper describes how sprinkler water spray would interact with a fire-induced hot layer. The field modelling technique is used and the problem is divided into gas and liquid phases. Experimental results reported by Walton and Budnick were used to verify the predicted results. For the gas phase, the set of conservation equations for mass, momentum, and enthalpy is solved numerically using the PISO algorithms. For the liquid phase, the sprinkler water spray is described by a number of droplets with initial velocity and diameter calculated by empirical expressions for the nozzle at different operating water pressures and flowrates. The trajectory of each droplet is calculated by solving the equation of motions, taking into account the dragging and heat transfer with the hot layer through which it travels. The water droplet is assumed to be non-evaporating, and the convective heat transfer coefficient is fitted by an empirical equation. Only the source terms at the gas momentum and enthalpy equations included the interaction effects with water droplets, that is, the Particle-Source-In-Cell method. The predicted results include the gas Sow, temperature, and smoke concentration field; the shape of the water spray; and some relevant macroscopic parameters such as amount of convertive cooling, drag to buoyancy ratio, and so on. Effect of the mean droplet size on those parameters is illustrated in this paper.
Original languageEnglish
Pages (from-to)84-91
Number of pages8
JournalInternational Journal of Modelling and Simulation
Volume17
Issue number2
DOIs
Publication statusPublished - 1 Jan 1997

Keywords

  • Computational Fluid Dynamics (CFD)
  • Drag to buoyancy ratio
  • Field models
  • Smoke logging
  • Sprinkler - hot layer interaction
  • Sprinkler water spray

ASJC Scopus subject areas

  • Software
  • Modelling and Simulation
  • Mechanics of Materials
  • Hardware and Architecture
  • Electrical and Electronic Engineering

Cite this