Project 1 : CFD Meshing for Tesla Cyber Truck

OBJECTIVE

For the given model, check and solve all geometrical errors and assign appropriate PIDs. Perform meshing with the suitable target length and element quality criteria.

PROCEDURE

Step 1: Topological cleanups 

• Do topo option to convert all single cons into double and triple cons.
• Use 3 point plane cut option to cut the model into halfs.
• Delete the right half side of model.
• Identify single and triple cons present if any.
• Solve all single and triple cons using intersect, delete,extend, new surface options.
• Delete and create new surface if outer surfaces are not good.
• Do geometry checks to confirm there is no cracks and triple cons are present.

Step 2: create and assign PIDS

• Go to properties box.
• Create two PIDs for body and tyre.
• Select two colors and apply them to the model.

Step 3: Surface meshing of model

• Isolate tyre PID.
• Give target length, minimum length and maximum length as 3mm, 1mm and 5 mm respectively in the mesh parameters and quality criteria.Select tria.
• Give perimeters and and macros as 3 mm.
• Do spot mesh. Change to hidden mode and check for off elements.
• If any off elements present, clear it using paste, split and move options or reconstruct option.
• Go to body PID.
• Give target length, minimum length and maximum length as 3mm, 1mm and 5 mm respectively in the mesh parameters and quality criteria.Select tria.
• Give perimeters and and macros as 3 mm.
• Repeat the above procedure for clearing the off elements from the body.

Step 4: Symmetry

• Click on transform option and go to copy.
• Select and symmetry and change to "3 point plane mirror".
• Select 3 points at different locations  in the extreme right of model.
• Do copy.If any single cons are present, do paste option.

Step 5: Creation of wind tunnel

• If the model has "x"mm length,then front face of wind tunnel should be "4x"mm distance from front point.
• Rear face should be"6x"mm distance from extreme back point of body and top face of wind tunnel should be "3x"mm  distance from extreme top point of model.
• Wind tunnel bottom surface should be at  very small distance from extreme bottom point of model.
• Wind tunnel side surfaces should be "x" mm ditance from extreme side points of body.
• Points for creating wind tunnel surface are using top- points- relative option.
• Give dy, dx and dz as per the above dimensions.
• Draw curve using cuve option.
• Create the bottom surface first.
• Offset the bottom surface in the upward direction to the required dimension.
• Create the other surfaces to complete the wind tunnel and delete the points and curves which created.
• Create PIDs for bottom,top, side, front and back surfaces of wind tunnel in the properties and apply them.  

Step 6: Meshing of wind tunnel

• For top surface give target length, minimum and maximum length as 100 mm, 80mm and 120 mm repectively in the mesh parameters and quality criteria. select tria.
• Give perimeters and macros as 100 mm.
• For bottom surface give target length, minimum and maximum length as 20 mm, 15 mm and 25 mm repectively in the mesh parameters and quality criteria. select tria.
• Give perimeters and macros as 20 mm.
• For the side, front and back surface turn off quality criteria. click on spacing. give dmin as 20 mm and dlmt as 100 mm.Give factor as 1.1.
• Mesh the surfaces seperately.

LEARNING OUTCOMES

• Understood how to do topological cleanups,create and asign PIDs.
• Understood how to do surface meshing on given model and how to perform symmetry.
• Understood how to remove off elements from surfaces.
• Understood how to create wind tunnel and how to perform meshing on it.

RESULTS

For the given model, checked and solved all geometrical errors and assign appropriate PIDs. Performed meshing with the suitable target length and element quality criteria.Created the wind tunnel and meshed it.

CONCLUSIONS

• Meshing of larger surfaces with small target length takes large time in meshing.But it reduces the number of off elements.
• In case of wind tunnel bottom surface is our  important suraface. so it should be meshed with small target length.