User:Egm6936.f09/Particle Reynolds number

EGM6936.f09.ku 16:44, 21 October 2009 (UTC)

Particle Reynolds number includes a correction to Stokes drag. For solid particles, it is


 * $$\phi(Re)=1+0.15 Re^{0.687}$$.

NOTE: See the question related to the particle Reynolds number in particle time scale.

The above equation is in Clift et al. (2005). To represent the deviation from the standard drag curve (Fig. 5.12 of the same book), relationships for sphere drag are given in Table 5.1, page 111. For Re<800,


 * $$C_D = \frac{24}{Re} \phi (Re_p)$$.

 It would be nice to explain how the above formulas were obtained. Egm6321.f09 01:23, 31 October 2009 (UTC)

A recent paper by Wu (2009) also referred to Clift et al. (2005) (p.112, Table 5.2) for a formula for the function $$\displaystyle \phi(Re_p)$$, denoted as $$\displaystyle f_d$$ in Wu (2009), for a smaller range $$\displaystyle 0.01 < Re_p < 20$$:
 * {| style="width:100%" border="0"

$$  \displaystyle \phi(Re_p) =  1   +   0.1315   Re_p^{0.82 - 0.05 \log_{10} Re_p} $$     (N)
 * style="width:95%" |
 * style="width:95%" |
 * 
 * }

= References =