2.8.3 Mass Transfer Coefficient

The mass transfer coefficients are based on the Reynolds analogy applied to the heat transfer coefficients. The following options are available in the fiber model to compute the exchange of mass between fibers and surrounding flow:

const-mtc   If you select this coefficient, you specify the direct transferred mass flow rate in $kg/(m^2 s)$, rather than the mass transfer coefficient.

kase-matsuo-1   A mass transfer coefficient based on a model from Kase and Matsuo [ 3] that considers pure parallel flow, see Equation  2.8-5.

kase-matsuo-2   A mass transfer coefficient based on a model from Kase and Matsuo [ 3] that also considers cross flow, see Equation  2.8-6.

gampert   A mass transfer coefficient based on a model from Gampert [ 2].

Gampert's analytical and numerical solutions for laminar axisymmetric flow of a moving cylinder in stationary air include strong curvature effects in the boundary layer, [ 2]. The Sherwood number is analogous to the Nusselt number as shown as dimensionless groups in Figure  2.8.1. This correlation is recommended for laminar flows.

user-defined   A mass transfer coefficient that you specify in a user-defined function (UDF). See Section  3.7 for more information on using UDFs in the fiber model.

Since these correlations are valid only for nearly-zero mass transfer due to the Reynolds analogy, a film theory is used to compute the non-zero mass transfer, see Equation  2.2-2.