Sauter mean diameter

Definition

The Sauter diameter (SD, also denoted D[3,2] or d32) for a given particle is defined as:

:SD = \frac{d_v^3}{d_s^2}

where d**s is the so-called surface diameter and d**v is the volume diameter, defined as:

:d_s = \sqrt{\frac{A_p}{\pi}}

:d_v = \left(\frac{6 V_p}{\pi}\right)^{1/3},

The quantities A**p and V**p are the ordinary surface area and volume of the particle, respectively.

The equation may be simplified further as:

:SD = 6\frac{V_p}{A_p}.

This is usually taken as the mean of several measurements n, to obtain the Sauter mean diameter (SMD):

:SMD = \sum_i^n SD_i / n

This provides intrinsic data that help determine the particle size for fluid problems.

Applications

The SMD can be defined as the diameter of a drop having the same volume/surface area ratio as the entire spray.

SMD is especially important in calculations where the active surface area is important. Such areas include catalysis and applications in fuel combustion.

References

References

1. Sauter, Josef. (1926). "Die Grössenbestimmung der in Gemischnebeln von Verbrennungskraftmaschinen vorhandenen Brennstoffteilchen". VDI publishing house.
2. (2013). "Fluidized Bed Technologies for Near-Zero Emission Combustion and Gasification". Elsevier.