15.3.2 Non-spherical Drag Law

For non-spherical particles Haider and Levenspiel [ 119] developed the correlation

where

$$b_1 = \exp(2.3288 - 6.4581\phi + 2.4486\phi^2)$$

$$b_2 = 0.0964 + 0.5565\phi$$

$$b_3 = \exp(4.905 - 13.8944\phi + 18.4222\phi^2 - 10.2599\phi^3)$$

$$b_4 = \exp(1.4681 + 12.2584\phi - 20.7322\phi^2 + 15.8855\phi^3)$$ (15.3-3)

The shape factor, $\phi$, is defined as

where $s$ is the surface area of a sphere having the same volume as the particle, and $S$ is the actual surface area of the particle. The Reynolds number $\rm Re_{sph}$ is computed with the diameter of a sphere having the same volume.

The shape factor cannot exceed a value of 1.