Week 4 Challenge : CFD Meshing for BMW car

Aim and objective:

For the given model, check and solve all geometrical errors on half portion and Assign appropriate PIDs. Perform meshing with the given Target length and element Quality criteria. After meshing the half model, Do symmetry to the other side.

1. Target lengths for the different parts of a model are as follow:
2. Body - 3 mm
3. Lights - 4 mm
4. Grills - 1 mm
5. Rims and Tyres - 2 mm
6. Optical Rear view mirror - 2 mm
7. Window - 2 mm
8. Silencer - 3 mm
9. Logo - 1 mm

Procedure:

1. Topo clean up of the model:

• Providing the fine length to the model

• Checking the single cons present in the model.

• Checking the triple cons present in the model.

• Starting topo clean up to the model. ANSA is a best tool for pre processing and in this we can mirror the mesh. Firstly deleting the half portion of the model for topo clean up.

Step 2- START 2D MESHING-

1. Target lengths for the different parts of a model are as follow:
2. Body - 3 mm
3. Lights - 4 mm
4. Grills - 1 mm
5. Rims and Tyres - 2 mm
6. Optical Rear view mirror - 2 mm
7. Window - 2 mm
8. Silencer - 3 mm
9. Logo - 1 mm

Start with meshing of smaller parts:

Grills Meshing:

Logo Meshing:

Lights meshing:

Silencer meshing:

Window and tyre meshing:

Body meshing:

PID names assigned after meshing:

CREATING OTHER HALF BODY USING SYMMETRY OPTION:

Our model is completely fine and ready to go for 3D meshing and creating wind tunnel:

Step 4- WIND TUNNEL CREATION

We will create a wind tunnel around car

Measurment for wind tunnels are-

• Consider length of car as X
• Keep wind tunnel at 75mm distance from bottom of car
• Length of wind tunnel from front of car should be 4X, total length of tunnel in front is half length of car added to 4X length
• Length of wind tunnel from back of car should be 6X, total length of tunnel from rear side is half length of car added to 6X length
• Height of wind tunnel should be 3X

Using sapcing tool:

Drive link: https://drive.google.com/file/d/1ezPlj0M5h_s83U_XgFXaBfN2eoo7FOsM/view?usp=sharing 

Conclusion:

• Working on the BMW model provided insight into the various meshing technologies offered by ANSA.
• Learned geometry cleanup and surface meshing in great depth. Problems encountered improved my understanding of tools
• Learned how to create a wind tunnel using points and curves and how to use the curve tool
• Learned about wind tunnel dimensions, such as what measurements to give based on model size.
• Advanced topo-cleanup and learned how to de-mesh when different PIDs with different mesh lengths are in contact with each other.