Edinburgh Research Archive >
Engineering, School of >
BRE Centre for Fire Safety Engineering >
BRE Research Publications >
Please use this identifier to cite or link to this item:
|Title: ||Smoke buildup and light scattering in a cylindrical cavity above a uniform flow|
|Authors: ||Upadhyay, Rochan|
|Issue Date: ||2005|
|Citation: ||Upadhyay, R.R., & Ezekoye, O.A. (2005). Smoke buildup and light scattering in a cylindrical cavity above a uniform flow. Journal of Aerosol Science, 346 471-493.|
|Abstract: ||In this study, we use computational fluid dynamics (CFD) and aerosol dynamics modeling to investigate the buildup of smoke and light scattering in a cylindrical cavity geometry, considered to be an idealized representation of a photoelectric smoke detector.
CFD coupled with the quadrature method of moments (QMOM) is used for simulation of aerosol dynamics. The Rayleigh-Debye-Gans/Polydisperse Fractal Aggregate (RDGPFA) theory is used for calculation of smoke extinction and angular light scattering. It is seen that the flow external to the cavity sets up a recirculating flow pattern within the cavity and that the flow processes determine the spatial distribution of smoke. Aerosol extinction and scattering calculations are performed to examine the time varying profiles of the intensity along a simulated LED light beam and the scattered intensity at different angles. The variation of the detector activation time with inlet velocity and smoke volume fraction is obtained from a calculation of the angular light scattering. The results are compared with calculations using an empirically determined detector response function and with a simpler model that assumes a uniform distribution of smoke inside the cavity. Results indicate that although the distribution of smoke inside the cavity is not uniformly mixed, the simple first order mixing model with appropriately chosen parameters is valid for predicting detector activation time.|
|Sponsor(s): ||Applied Research Laboratories, University of Texas at Austin|
|Keywords: ||Fire safety engineering|
|Appears in Collections:||BRE Research Publications|
This item is licensed under a Creative Commons License
Items in ERA are protected by copyright, with all rights reserved, unless otherwise indicated.