Danckwerts Inflow Boundary Condition
Constraining the composition to fixed values at an inlet to a reactor may sometimes result in issues with unreasonably high reaction rates or singularities at the inlet boundary. These problems may many times be mitigated by using a flux boundary condition instead, based on the upstream concentrations and the fluid velocity at the boundary. In chemical engineering, this type of flux boundary condition is also known as a Danckwerts condition.
Use the Danckwerts condition to specify inlet conditions for domains where high reaction rates are anticipated in the vicinity to the inlet (
Ref. 2
).
Given an upstream concentration
c
i
,
0
, the Danckwerts inflow boundary condition prescribed the total flux as
(5-18)
