|Title:||Drag force on a floc in a flow field: two-layer model||Authors:||Hsu, Jyh-Ping
|Keywords:||floc;porous structure;drag coefficient;two-layer model||Issue Date:||2002||Publisher:||Taipei:National Taiwan University Dept Chem Engn||Start page/Pages:||2627-2633||Source:||CHEMICAL ENGINEERING SCIENCE 57(14)||Abstract:||
The behavior of a oc in a ow !eld is analyzed theoretically; in particular, the force it experienced is estimated. Here, a oc is simulated
by an entity having a two-layer type of structure, and its porous nature mimicked by varying the relative magnitudes of the permeability
of its inner layer and that of its outer layer. The results of numerical simulation reveal that, for the same volume-averaged permeability,
the drag coe6cient of a oc with a heterogeneous structure is always much larger than that of a oc with a homogeneous structure. This
is true regardless of the relative magnitudes of the permeability of the inner layer and that of the outer layer. The drag coe6cient of a
oc is mainly determined by the part having a less porous structure. We show that for the same volume-averaged permeability, the more
heterogeneous the structure of a oc is, the easier for the relation between the drag coe6cient and the Reynolds number to deviate from
a Stokes’ law-like correlation.
|Appears in Collections:||化學工程學系|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.