Schmidt number Subject

The convective mass transfer coefficient hm can be obtained from correlations similar to those of heat transfer, i.e. Equation (1.12). The Nusselt number has the counterpart Sherwood number, Sh = hml/Di, and the counterpart of the Prandtl number is the Schmidt number, Sc = p/pD. Since Pr k Sc k 0.7 for combustion gases, the Lewis number, Le = Pr/Sc = k/pDcp is approximately 1, and it can be shown that hm = hc/cp. This is a convenient way to compute the mass transfer coefficient from heat transfer results. It comes from the Reynolds analogy, which shows the equivalence of heat transfer with its corresponding mass transfer configuration for Le = 1. Fire involves both simultaneous heat and mass transfer, and therefore these relationships are important to have a complete understanding of the subject. 

In what follows, the equation of diffusion derived in Chapter 2 is generalized to take into account the effect of flow. For point particles (dp = 0), rates of convective diffusion can often be predicted from theory or from experiment with aqueous solutions because the Schmidt numbers are of the same order of magnitude. There is an extensive literature on this subject to which the reader is directed. For particle diffusion, there is a difference from the usual theory of convective diffusion because of the special boundary condition The concentration vanishes at a distance of one particle radius from the surface. This has a very large effect on particle deposition rates and causes considerable difficulty in the mathematical theory. As discussed in this chapter, the theory can be simplified by incorporating the particle radius in the diffusion boundary condition. 

Humberston et al. 2003 Musch et al. 2006 Russmann et al. 2003 Sass et al. 2001 Schmidt et al. 2005 Stoller 2000). These reports have been subject to critical analysis by a number of organizations and individuals (Schmidt 2007 Schmidt et al. 2005 TMEC 2002 Waller 2002). A review of liver toxicity cases indicated that the reported cases represented unpredictable reactions, and that cases were best characterized as idiosyncratic reactions of the metabolic type (Teschke et al. 2008). Of 82 cases of liver toxicity reported through 2002, one case was assessed as being "certain" or "probable" by multiple reviewers, with up to 12 others being noted as "probable" (BfArM 2002 Schmidt 2007)... 

The free ion yields strongly depend on the molecular structure in linear alkanes the yields are low, the yields increase with the increasing branching. There is a positive correlation between the free ion yields and the mobility of electrons in the hydrocarbons. Since the yield and mobility of electric charge carriers in insulators like hydrocarbons is very important from both theoretical and practical point of view, a large number of papers were devoted to this subject and there are some good review papers as well (Hummel and Schmidt 1974 Holroyd 1987 Holroyd and Schmidt 1989 Holroyd 2004). 

NDT Documents, frames 3/29i4f. also frames 3/1094-7 Klee 1997, p. 366 Schmidt 2007a, p. 293. Other sources suggest a total number of approximately 150 experimental subjects of whom about forty died also Mitscherhch, MieUce 1962, pp. lyof... 

Two other historical asides about this result are interesting. First, the dimensionless quantities b and b suggested by Reynolds were renamed y-factors by Chilton and Colburn. These factors are common in the older literature, especially as Jd and Jh. Second, the exponent of on the Schmidt and Prandtl number is frequently subjected to theoretical rationalization, especially using boundary-layer theory. Chilton is said to have cheerfully conceded that the value of was not even equal to the best fit of the data, but was chosen because the slide rules in those days had square-root and cube-root scales, but no other easy way to take exponents. 

---