'CFD homework 1' simulation project by adonninelli


#1

I created a new simulation project called 'CFD homework 1':

Mixing of flow through pipe


More of my public projects can be found here.


#2

1 Mesh

Fig. 1 Coarse mesh

Fig. 2 fine mesh

Coarse and fine mesh is created using automated SnappyHexMesh for internal flow.
Steady state laminar simulation is performed for these two meshes, according to the assigned settings.

1.1 Results
Post-processing is performed by local Paraview, the results show Pressure and Velocity fields and streamlines.
1.1.1 Coarse mesh

Fig. 3 Pressure field

Fig. 4 Velocity field

Fig. 5 Streamlines

1.1.2 Fine mesh

Fig. 6 Pressure field

Fig.7 Velocity field

Fig. 8 Streamlines
As can be seen from the images above, expecially for the velocity field, the fine mesh simulation can capture more specific behavior of the flow, like flow separation and vorticity in the area after the middle inlet and a more extended low velocity area after the elbow of the pipe.
This is possible because smaller cell’s volumes ensure more accuracy, smaller errors during the integration and then smaller propagation of the solution errors. The smaller cells can also better copy the volume and surface of the pipe with less misalignment between cells.