Single point flame

The mean rate of energy release S and the rate of consumption/production of species j, Vj, are calculated on the basis of the detailed or reduced reaction mechanism of fuel oxidation in air and a single-point bimodal normalized PDF of temperature P T, T) in the turbulent flame brush ... 

Fig. 3. Intermediate species curve. The negative portion of the Gi curve represents a net flux of the species towards the cold gases. For the constant enthalpy single-reaction flame, the curve for Gi cuts across that for Xi at the maximum point of...

The images of the single-brush flame were complemented by profiles of temperature, velocity, and calculated strain rates at the stagnation plane (not shown here), and the effects of forcing amplitude and frequency on the reduction in the mean extinction strain rate close to the axis were quantified while previous results [15] were extended to include the effects of bulk velocity and separation on extinction times. The amplitude of imposed oscillations was quoted in terms of the rms of the axial velocity fluctuations at the nominal stagnation point normalized by the bulk velocity [14],... 

Bandaru and Turns [3] presented experimental results on radiant heat fractions based on the single-point source assumption for flares. They presented radiant heat fraction values between 7% and 12% for ethylene flames and noted that the results did not correlate clearly with momentum flux ratio. For propylene and methane flames, Goh and Gollahalli [20] showed that the effects of piloting caused the flame radiation to decrease. Schmitt [68] measured the radiation and dimensional characteristics of hydrogen flares. 

In general, there are three fundamental approaches for semiempirically modeling flare radiation. The simplest approach is to assume that all of the heat emitted from the flame is concentrated at a single point within the flame (epicenter). All of the heat emitted from the epicenter radiates outward and evenly distributes its energy over the entire surface of a sphere this type... 

The advantage of the single-point model is that it is the simplest, mathematically, of the three models. The disadvantage, however, is that when the point of interest is located near the flame, the flame cannot be treated as a... 

Plastics—The Acquisition and Presentation of Comparable Single-Point Data Plastics—Determination of the Burning Behaviour of Specimens Using a 500 W Flame Source Plastics—Differential Scanning Calrimetry (DSC)—Part 2 Determination of Glass Transition Temperature... 

Equation (3.60) assumes that all radiation arises from a single point and is received by an object perpendicular to this. This view factor must only be applied to the total heat output, not to the flux. Other view factors based on specific shapes (i.e., cylinders) require the use of thermal flux and are dimensionless. The point source view factor provides a reasonable estimate of received flux at distances far from the flame. At closer distances, more rigorous formulas or tables are given by Hamilton and Morgan (1952), Crocker and Napier (1986), and TNO (1979). 

Quantitation—The flame photometric detector responds logarithmically to the mass of the sulfur present in the flame. Some GC/FPD systems are programmed to linearize logarithmic data, and with such systems the output can be correlated directly with the COS concentration, using a single point calibration. Calculate a calibration factor, F, in accordance with Eq (1) below ... 

Yokoi (1960) [3], singly produced a small book as a report, which carefully investigated point, line and finite heat sources with eventual applications to the hazard from house fire and window flame plumes. 

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