Modelling Of Unconfined Flame Tilt In Cross-Winds

Abstract

Experiments were conducted to characterize the effects of crosswind on flame properties for unconfined fires. Propane gas was used as a fuel in a O.lm XO.lm diffusion burner employed as a model fire source. The effects of the floor around a fire source, which would control the volume of air entrained into the hot current, were also investigated. Empirical models of the apparent flame height of the inclined flame are presented. We also develop empirical models of the flame tilt angle based on the balance of mass fluxes given by the upward hot current and crosswind. These models are based on functions of dimensionless heat release rate and Froude number. The values of empirical coefficients and exponents were derived from the experimental results. The calculated flame length based on the flame tilt angle and the apparent flame height was compared with experimental results, showing that models can be used to estimate flame length in crosswinds .

Progress in Scale Modeling, Volume II

“…9). This is consistent with analyses of flame drag (flame trailing) downwind of pool fires which typically scale with the diameter of the flame source [31,32]. The implication here is that the downwind extent to which flames are intermittently heating fresh fuel ahead of the ignition interface is related to factors producing flame drag.…”

“…That situation in the scale modeling of geotechnical engineering may well represent the relationship between engineering and science described by Williams [30]. Giving a centrifugal acceleration to a geotechnical model may be "kufu" that is appreciated as a fourth research tool by Emori [31] as explained by Saito [32]. If it is not considered "kufu," the technique involved in centrifuge testing, is definitely a powerful tool for use in geotechnical engineering.…”

“…It should be noted that metagenomics could not evaluate the distinction between living bacteria and dead bacteria. Figure 3 shows the procedure of metagenomic analysis: extraction of DNA mixture from RDF, multiplication of ligation of 16SrDNA, transformation of component, bacteria growth on agar, blue/white color screening for recombinants, multiplication of 16SrDNA of each bacteria, sequence of 16SrDNA of each bacteria, and finding query sequence and data match [31]. …”

Tilt angle of turbulent jet diffusion flame in crossflow and a global correlation with momentum flux ratio

“…In 2000, Oka et al . [6] developed an empirical model of the tilt angle of diffusion propane flame by assuming that the tilt angle was controlled by the balance of the upward hot current and crosswind at the average flame height. This model qualitatively coupled the flame tilt angle with the dimensionless heat release and source Froude number.…”

Effect Of Cross-Winds To Apparent Flame Height And Tilt Angle From Several Kinds Of Fire Source

“…The research on flame shape and plume property from a single fire source in the presence of cross-winds in unconfined space was reported by Thomas [1], AGA [2] and other researchers [3][4][5]. Oka and Sugawa also have conducted some experiments and proposed the empirical formulae on the apparent flame height and flame tilt angle [6,7]. These models were derived based on experimental results with a square burner of 0.1 m x 0.1 m and releasing dimensionless heat release rate, Q*, ranging from 0.2 to 4.5.…”