Abstract: In order to break through the limitation of traditional study on behavior of flow and mass transfer by
material objects, CFD ( Computational Fluid Dynamic) simulations of PABR ( Periodic Anaerobic Baffled
Reactor) on RTD(Residence Time Distribution) was carried out in this paper, supporting implementing schemes
to economize manpower and material resources in configuration improvement, simulation of operating mode, risk
monitoring and forecast. A three-dimensions modeling of the tap water body in the PABR modelled by SOLID
WORKS was meshed by COMSOL. Then, RTD simulating test was performed by unidirectional flow layer
module, thin mass transfer module and transient solver, based on the boundary conditions of lab-scale
experimental material object. Normalized integration of the normalized curves of both the material object and the
simulating was fitted and calculated by Matlab, and the similarity of the two curves was acceptable. Finally, the
behavior of tracer in the flow and diffusion procedure was visualized by post-processing with COMSOL, and
human-computer interaction was achieved.

Key words: residence time distribution(RTD), computational fluid dynamics(CFD), periodic anaerobic baffled reactor(PABR)