Surface and Volumetric mesh of Turbocharger

Objective – To Mesh the Turbocharger Model using ANSA

Procedure-

We started with opening the shared file in ANSA and as expected it had a lot of topo errors like extra surface ,single cons and extruded surfaces.

We also used the geometry check option from the utility window to look for the errors.the same has been illustrated in the figure given below.

Fig. 1 Errors in the provided CAD file

We started with getting rid of these errors as these are undesirable for CFD analysis.

We used various options from the utility window.

They are-

• Coons-to create missing surfaces
• Hot points- near the impeller casing the surface missed was not patched using coons options due to complexion in its geometry so we used hot points and patched the surface in parts.

Fig. 2 Before patching After patching

• We used delete options several time to del the unwanted surfaces
• We used projection and intersection command to get rid of extruded surface on the compressor casing.

After cleaning the geometry the wire frame mode of our model was this.

Fig. 3 After geometry clean up

After cleaning the geometry we went for assigning PID to the model.

While doing so we had merge blades of stage 1 and 2 ,shaft rotor and the impeller to the same PID.

Previously they were different as shown in fig.

Fig. 4 Before merging into single volume

So we did that by merging them and deleting the extra surfaces.

Fig. 5 Delting the shared surface to merge them in to single volume

Fig 6 Rotor PID merged

After that we assigned the PIDs .

And after that we compressed our model to get rid of the PIDs assigned earlier but were deleted during geometry clean up.

Fig. 7 Before compressing

Fig. 8 After compressing

After assigning PIDs we were all set to go for surface meshing which is length oriented.

The respective length for the same is as follows

Impeller – 2mm

Shaft rotor – 1mm

Turbo casing – 5mm

Compressor casing – 5mm

Blade stage 1 – 1mm

Blade stage 2 – 1mm

Impeller casing – 5mm

And we were successfully able to perform the surface length oriented mesh.

Fig. 9 Length oriented surface mesh

Now we moved to perform the volumetric mesh and for that we had to close our model completely.

We did that by covering up the

Compressor inlet , compressor outlet, impeller inlet and impeller outlet using faces option in the utility window and assigned PIDs to them with the same name they were associated with and meshed them and we got the following result.

Fig. 10 Enlosed and meshed

After this we moved to volumetric mesh using the V. Mesh in the utility menu and defined the volume first.

There we got 9 different volumes including both desirable and non-desirable.

We deleted the non-desirables and remeshed them and applied TETRA-CFD option provided in the GUI of ANSA and we got the following result.

Fig. 11 volumetric mesh

Fig. 12 Section View

Results-

We were successfully able to mesh the given model using ansa and hence our objective was completed.

Google Drive Link - https://drive.google.com/open?id=1jmndcGdKI-jlYNh5JJON8qqm14UuM7NI