Project 1 : CFD Meshing for Tesla Cyber Truck

Aim:

• Check and solve all the geometries.
• Assign proper PIDs.
• Perform meshing with suitable target length and element quality.

Take away:

• One will be able to clean up the CAD using different tools.
• Assign PIDs.
• Mesh with appropriate mesh length.

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Pre-Geometry clean up:

• As seen in the above figure, there are lot of single cons present in the geometry. One must avoid it.
• Initially, run a topo check. (TOPO DECK >> FACES >> TOPO).

• Since there are not much errors to resolve, we will still solve it individually.

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Body clean up:

>> Exploring NEW option:

• This tool creates a surface or face where there is no face or surface.
• Select NEW option. (TOPO >> FACES >> NEW).

• Other place where we can use NEW option.

• Run check manager.

• Cross indicates an error and a tick indicates no error.
• Remaining errors.

• There is intersecting surfaces.

• This can be cleaned using UNIVERSAL DELETE option present in the ribbon.

• At this stage, there are no single cons.

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Assigning PIDs:

• Assigning PIDs to the component makes it easy bifercate and visualize them.
• Open PID dialogue box present in ribbon.

• Right click in the open space.
• Select NEW and then select SHELL PROPERTY.

• Assign the PIDs as follows:

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Meshing:

Body = 3 mm.

Windows = 2 mm.

Tyres = 2 mm.

>> Meshing Tyres:

• In order to assign quality criteria one must know the minimum and maximum length present in the geometry.
• Measure it using the measure tool.
• Target Lenght = 5 mm.
• Maximum Lenght = 6 mm.
• Minimum Lenght = 2 mm.

• Select LENGHT option. (MESH DECK >> PERIMETERS >> LENGTH).
• After specifying the length, select SPOT MESH option. (MESH DECK >> MESH GENERATION >> SPOT MESH).
• The Mesh:

• Off elements:

• To remove off elements, try using RECONSTRUCT option. (MESH DECK >> SHELL MESH >> RECONSTRUCT).

• No more off elements!

>> Meshing Windows:

• In order to assign quality criteria one must know the minimum and maximum length present in the geometry.
• Measure it using the measure tool.
• Target Lenght = 5 mm.
• Maximum Lenght = 6 mm.
• Minimum Lenght = 3 mm.

**Correction: minimum lenght = 3 mm.

• Select LENGHT option. (MESH DECK >> PERIMETERS >> LENGTH).
• After specifying the length, select SPOT MESH option. (MESH DECK >> MESH GENERATION >> SPOT MESH).
• The Mesh:

>> Meshing Body:

• Before meshing, remove all the unecessary cons that might affect the mesh quality.

• Remove some more if present.

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Creating Wind Tunnel:

• Create the first point as reference to make sure that ground is lower than the tyre.
• To create a point below tyre surface, select RELATIVE option. (TOPO DECK >> POINTS >> RELATIVE).
• Give a distance of 500 mm in negative Z direction.

• Distance from front of the car to rear of the car = x = 5746 mm.
• Distance from front face of the car to the inlet of the wind tunnel = 2614 + 4x = 25602 mm.
• Distance from rear face of the car to the outlet of the wind tunnel = 3310 + 6x = 37792 mm.
• Side walls of the wind tunnel are 3 time the width of the car = 3*1880 = 5640 mm.

• Top view of points created.
• Using this points one can create surface/face.
• First create curves and then using those curves create surface/face.
• Select CREATE option. (TOPO DECK >> CURVES >> CREATE).
• Now, create top surface of the wind tunnel.
• Top surface = 2301 + 3x = 19542 mm.
• To create top surface, select OFFSET option. (TOPO DECK >> FACES >> OFFSET).
• Select bottom surface as reference.

• Wind Tunnel is ready.
• Assign respective PID.

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Meshing Wind Tunnel:

• Bottom Wall = 100 mm.
• Top Wall = 200 mm.
• For side, inlet and outlet, we will be using variable meshing along the verticla length.
• Select SPACING option. (MESH DECK >> PERIMETERS >> SPACING).

• Final mesh is shown below:

• Volumetric Mesh is not done due to limited CPU performance.

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Conclusion:

• Was able to clean up the geometry using different tools.
• Assigned respective PIDs.
• Performed part wise meshing.
• Creation of wind tunnel and its meshing.

Module Link:

https://drive.google.com/file/d/1uzHss2mFUbp-42Nv4lCTarAxrMA94wTI/view?usp=share_link