Configuration factors

Fn = view factor or geometric configuration factor E = emissive power of emitting surface 2 = incident radiation-receiving surface... 

Buschman, Jr., A. J., and C. M. Pittman. 1961. Configuration factors for exchange of radiant energy between antisymmetrical sections of cylinders, cones and hemispheres and their bases. NASA, Technical Note D-944. 

Howell, J. R. A Catalog of Radiation Configuration Factors (McGraw-Hill, New York, 1982)... 

The steric and configurational factors discussed above would suggest that five-membered rings should form somewhat more readily than rings of six or seven members, but they offer no explanation for the total exclusion of intermolecular condensation, nor do they explain the much greater rate of intramolecular reaction of five-membered units as compared with the rates of intermolecular reaction of larger units. A possible partial explanation for these peculiarities of five-membered... 

Pc = pitch configuration factor (pc = 1 for square pitch, pc = 0.866 for triangular pitch)... 

The emission coefficient was taken to be a constant value close to unity. The configuration factor, F, was calculated in a conventional way, treating the center of each strip as a point. Once the downward flame spread started the radiation from the wall flames and the pyrolysing lining material behind the flames was added to the smoke layer radiation. The heat flux to the walls was then calculated from the expression... 

F 12 is radiation view (configuration) factor between the target and the flame (0 < < 1)... 

Figure 5-10. Maximum Configuration Factor for a Flame Height to Pool Fire Radius Ratio Hf/Rp=2...

Wiebelt J.A., Ruo S.Y. (1963) Radiant-interchange configuration factors for finite right circular cylinder to rectangular plane. International Journal of Heat Mass Transfer 6, 143-146. 

Calculate the plate height contributed by sorption-desorption mass transfer (nonequilibrium) through a uniform liquid layer (configuration factor q = 2/3) of thickness 1.0 x 10 3 cm coated on the inside of an open tubular (capillary) column. The gas velocity v is 10 cm/s. The solute retention ratio is 0.10 and its diffusion coefficient Ds through the stationary liquid is 1.0 x 10 5 cm2/s. 

Compressibility factor, 61-63 Configuration factor, 33 Countercurrent chromatography, 74 Critical point data, 250 Cryogenic GC, 149 Cyclodextrin, 266... 

Other parameters in this important C term are >L, the diffusion coefficient in the liquid phase, q, and the ratio kl( 1 + k).2 The diffusion coefficient should be large, but often this choice cannot be exercised because the liquid phase is chosen for selectivity reasons. Previously, it had been thought that higher diffusion coefficients would be found in stationary phases of low viscosity. This is true only for small molecules for polymers of the type used in GC, the diffusion coefficient is virtually independent of viscosity.7 Of course, these polymers cannot be used below their glass temperatures, so low viscosity polymers may be required for low temperature GC column operation. The configuration factor q is determined by the type of bed and is for uniform films preferred in GC. The k ratio should be relatively large, as we have seen. 

Other names for the radiation shape factor are view factor, angle factor, and configuration factor. The energy leaving surface 1 and arriving at surface 2 is... 

Hamilton, D. C., and W. R. Morgan Radiant Interchange Configuration Factors, NACA Tech. Note 2836, 1952. 

F —2 is called the configuration factor, the geometric factor, or the shape factor. This has been integrated for many common configurations, two of which are plotted in Figs. 7.1 and 7.2. Other figures are presented in the literature, particularly Krieth [2], Chapman [7], and Siegel and Howell [9]. 

FIGURE 7.1 Configuration factors for two rectangular figures with a common edge, at right angles [7]. 

The enclosure property also serves as a check to determine whether all the separately determined configuration factors are correct. 

Evaluate the configuration factors. The furnace can be sketched as in Fig. 7.3. Each of its six faces has a roman numeral and (for convenience later in the problem) the temperature of that face is shown. Since heat radiated from each face will impinge on every other face, there are 6(6 — 1) = 30 configuration factors to be determined. However, because of the reciprocity property and symmetry, fewer calculation steps will be needed. 

Related Calculations. If the six surfaces are not black but gray (in the radiation sense), it is nominally necessary to set up and solve six simultaneous equations in six unknowns. In practice, however, the network can be simplified by combining two or more surfaces (the two smaller end walls, for instance) into one node. Once this is done and the configuration factors are calculated, the next step is to construct a radiosity network (since each surface is assumed diffuse, all energy leaving it is equally distributed directionally and can therefore be taken as the radiosity of the surface rather than its emissive power). Then, using standard mathematical network-solution techniques, create and solve an equivalent network with direct connections between nodes representing the surfaces. For details, see Oppenheim [8],... 

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