Project description

The local mass transfer coefficient in the gas phase has a maximal value at the edge of the concentration boundary layer and decreases in the direction of the air flow. This might lead to a laterally inhomogeneous drying process, in the case of a polymeric system, whose drying rate is mainly controlled by the mass transport in the gas phase.

The following figure shows the important parameters of this theory. With changing x and x_0, the local drying rate can be predicted well.

The goal of this project is to predict the local drying process from any position of any film with the theory of local mass transfer coefficient with microscopic method and to drop out the drying process of the whole film with the gravimetric method. In addition, it is also a part of this work to find out, weather there are other influencing factors, e.g. the position in the direction that is across to the air flow.