VMFL006

VMFL006
Multicomponent Species Transport in Pipe Flow

Overview

ReferenceW.M. Kays and M.E. Crawford. Convective Heat and Mass Transfer. 3rd Edition. McGraw-Hill Book Co., Inc., New York, NY. 126-134. 1993.
SolverAnsys Fluent
Physics/ModelsSteady laminar flow, species transport
Input FileSpecies-diffusion.cas
Project FilesLink to Project Files Download Page

Test Case

Fully developed laminar flow in a circular tube, with two species is modeled. Species A enters at the inlet and species B enters from the wall. Uniform and dissimilar mass fractions are specified at the pipe inlet and wall. Fluid properties are assumed to be the same for both species, so that computed results can be compared with analytical solution.

Figure 8: Flow Domain

Flow Domain

Material PropertiesGeometry Boundary Conditions

Species A

Density = 1 kg/m3

Viscosity = 1.0 x 10-5 Pa-s

Diffusivity BA = 1.43 x 10–5 m2/s

Species B

Density = 1 kg/m3

Viscosity = 1.0 x 10-5 Pa-s

Diffusivity AB = 1.43 x 10-5 m2/s

Length of the pipe = 0.1 m

Radius of the pipe = 0.0025 m

Fully developed laminar velocity profile at inlet with an average velocity of 1 m/s

Mass fraction of species A at pipe inlet = 0.5

Mass fraction of species B at pipe inlet = 0.5

Mass fraction of species A at pipe wall = 0.9

Mass fraction of species B at pipe wall = 0.1

Analysis Assumptions and Modeling Notes

The flow is steady. A fully developed laminar velocity profile is prescribed at the inlet. Species transport model is used.

Results Comparison

In the following table, the value of species A is the mass-weighted average of the normalized species mass fraction A at x-locations.

Table 9: Comparison of Mass Fraction of Species A Along the Axis

Axial location (m)TargetAnsys FluentRatio
0.010.82250.82271.002
0.020.73080.73091.001
0.030.65930.65941.002
0.040.59920.59931.002
0.050.54690.54711.004
0.060.50060.50071.002
0.070.45890.45911.004
0.080.42120.42151.007
0.090.38690.38721.008
0.100.35550.35571.006