Project 1 : CFD Meshing for Tesla Cyber Truck

Aim:

To perform geometry clean-up of the cyber-truck, assign PID’s and develop a wind tunnel while perform meshing with mesh sizes

Link for the meshed model : https://drive.google.com/file/d/1dXW5ZD9AAM4Rp3H0VifxgUKsaW3vCaSu/view?usp=sharing

https://drive.google.com/file/d/1dXW5ZD9AAM4Rp3H0VifxgUKsaW3vCaSu/view?usp=sharing

Objectives:

1. To perform geometry cleanup

2. To assign the different PID's to different parts of the cybertruck

3. To mesh with different mesh sizes and evaluate the mesh sizes.

4. Develop the wind tunnel model around the car and perform meshing using options like spacing.

Procedure:

• Due to the symmetry of the car, only left part of the car was selected for cleaning up the geometry.
• For this, initially a plane was created and later the symmetrical half is deleted.
• Initial geometry check was performed for single cons and triple cons.
• Irrelevant surfaces that are inside the Car body is deleted to have a single volume.
• No triple cons were found, however single cons present were deleted.
• Common surfaces near the intersecting bodies were deleted to get a single close volume.

• PID’s were created for the different parts like tyres, windows, mirror, Bottombody, topbody, light holders for front and back, and lights.
• Every PID region is meshed leaving top body.
• Measure option is used to check the length and macros to confirm whether mesh criteria will be attained.
• Mesh criteria is below:

  1. Body top-3mm

  2. Lights-4mm

  3. Body bottom - 3mm

  4. window - 2mm

  5. tyres-2mm

  6. Light holding front and back - 2mm

  · Meshing is performed and reconstruct option was used. So that the off elements are corrected.

  · Mesh sizes are readjusted especially for the tyres as the smallest geometry was 0.2mm and also the skewness is adjusted to 1.0 exclusively for tyres.

  • The meshing is performed until all the PID’s are meshed.
  • For meshing the top body and maintaining the continuity, the coons near the contact points are deselected and later on meshed. .
  • Transform option with symmetry is used after meshing half of the car.
  • New single cons formed were rectified using paste option.

  Development of the wind tunnel:

  · The wind tunnel is developed using curves and points options.

  · The dimensions of the wind tunnel are as follows:

  o x=5850

  o half distance = 2730

  o distance from bottom to floor = 385

  o front view half distance = 2030/2 =1015

  o height of the car = 1530

  o 4x+2730=26130 at the front

  o 6x+2730=37830+400 at the rear

  o 3x+1530+385=19465 at the top

  · Appropriate PID’s are created for the wind tunnel.

  · New surfaces are created accordingly using fitted surfaces option.

  · Bottom surface and top surfaces are meshed with the below parameters and while side,back and front surfaces are meshed using the spacing option in the mesh tab.

  o Top surface perimeter length = 250mm

  o bottom = 50

  · The mesh is created using spot mesh tab and local sizes.

  · Later for the volume meshing the body were defined.

• Result:

  • Geometry clean-up was performed on the half of the cybertruck
  • Meshing was performed as suggested.
  • Transform option was used to develop the whole car.
  • Wind tunnel is developed and meshing was performed as suggestedConclusion:

  1. Planes should be created to exactly cut the truck body into half.

  2. Geometry checks needs to done whether the symmetry option is used or not.

  3. Geometry cleanup should be performed before meshing using checks.

  4. Quality criteria should be decided before starting of the mesh which will reflect the mesh adapting to the actual body.

  5. After transformation into full body, care should be taken to avoid the single and triple cons.

  6. All the geometry should be ideally cleaned before proceeding to the meshing, including whether the cons have sizes suitable for meshing. After meshing macros option can be used to cut the cons so that the mesh qualifies the quality criteria.

  7. Meshing should be available on all the PID’s.

  8. Development of wind tunnel should be done according to the specifications and also needs to meshed diligently.