Advanced Pre-processing of BMW M6 Model Using ANSA

Advanced Pre-processing of BMW M6 Model Using ANSA.

Aim -

• To rectify the topological errors in the model.
• To assign proper PID\'s to the model and Mesh the model properly.
• Eliminatng mesh errors in the mesh of the model.
• Creating Wind tunnel around the model to perform External flow analysis.

Procedure -

1. Importing and setting up the model.
2. Identifying and eliminating the topological errors.
3. Assigning PID\'s to the Model.
4. Setting the mesh parameters and creating the mesh.
5. Identifying and Eliminating the errors from the created mesh.
6. Creating the Whole model using Symmetry Option.
7. Creating the Wind Tunnel around the model.

1) Importing and setting up the model -

Import the model from -

File > Open > Browse the location of the model > Select it and open

Change it to PID mode

Toolbar > Quality Criteria > Presentation Parameters > Select Draw CONS in PID, MID, ....like in ENT mode > Apply > OK.

2) Identifying and eliminating the topological errors -

• As seen from the above image we can see a lot of topological errors like single cons and missing faces in the model. We have to eliminate this errors.
• Disable Macro option from the below toolbar and we can see Design lines which are not needed. So We delete this.

• The given model has symmetry so we can delete the other half and work on the remaining part and then create the other part using symmetry after cleanup.

• Now we will do the geometry checkup and see the errors in the model.
• Checks > geometry checkup > Execute

• After cleaning the errors from the model,

• After cleaning up the model, geometry check-up is done again.

3) Assigning PID\'s to the Model -

Setting PID\'s of the model to better understand the model and various components of the model

4) Setting the Lengths and creating the mesh -

Mesh according to the lengths of various PID\'s -

Body - 3 mm

Lights - 4 mm

Grills - 1 mm

Tires and Rims - 2 mm

Windows and ORVM - 2 mm

Exhaust - 3 mm

Logo - 1 mm

and element must be TRIA.

Surface mesh > Perimeter > length > perimeter/macros > Select the part > Middle mouse button > enter the length > Click Middle mouse button

Surface Mesh > Mesh > Free > Visible/Select the part > Middle mouse button

Now Check Surface mesh Quality -

Checks > Checks Manager > Surface mesh Check > Execute

5) Setting mesh Parameters and Identifying and Eliminating the errors from the created mesh -

We get errors such as Skewness,minimum angle, minimum length or maximum length.

After getting rid of this errors the mesh looks as follows -

Mesh checkup -

6) Creating the Whole model using Symmetry Option -

7) Creating the Wind Tunnel around the model -

To perform the External flow analysis on the model there is a need to create a wind tunnel.

So we create a wind tunnel around the model.

Wind tunnel dimensions -

4 X length of Car in front of the Car.

6 X length of Car in rear of the Car.

3 X length of Car in top of the Car.

1 X length of Car from the centre plane to the left and right sides.

And Bottom plane to be at close proximity to tires.

Meshed Wind tunnel -

Google drive link -

https://drive.google.com/drive/folders/1s3pF0Wef3BILjUGCbRaNJVvq6yyktoJo