Project 1 : CFD Meshing for Tesla Cyber Truck
AIM/OBJECTIVE
To perform the volumetric mesh of the given Tesla Cyber Truck model for a varying target length. Check for the geometrical error and perform topology cleanup accordingly. Use the element type tria. Also create and assign PIDs
PROCEDURE
Step-1 : Load the given Tesla Cyber Truck file in ANSA software
Step-2 : Since all the cons are in red do the Topo tool in faces to clear all the single cons that can be conveted into double or triple cons.
Step-3 : In the model we can observe many required surfaces are missing and unwanted are present. Create new faces and delete unwanted surfaces.
Step-4 : For the ease of the meshing and geometric topo clean up I divided the model into two equal halves using plane cut tool.
Step-5 : The half portion of the model is rectified for single and triple cons except for the symmetry surface where we need to do the symmetry. Inside of the car is made into one single volume for the ease of volumetric meshing. Unwanted geometry are deleted for the ease of meshing.
Step-6 : PIDs for the various parts of the models are assigned
1. Body
2.Bumber
3. Wheel Skirt
4. Window
5. Light
6. Tyre
Step-7 : Now the other side of the car is obtained using tranform symmetry tool using Mirrir 3 points pane
Step-8 : Before going to surface meshing check again for any geometrical errors using the checks manager.
Step-9 : Surface meshing is done for the model. The following Mesh length and quality criteria were used to perform meshing. Reconstruction is used to get optimum meshing results. Off elements are checked and rectified accordingly. Additional to reconstruction I have used Smooth and Fix Quality tools in the shell mesh. By doing so off elements can be reduced drastically.
Step-10 : Next the wind tunnel is constructed around the model. The length, breadth,width and height of the model are measured using measuring tool. The distance of the wind tunnel surface from the model is as below given
Top Surface - 3x distance from the top of model
Bottom Surface - Just below the typre surface
Front Surface - 4x distance from the front of model
Rear surface - 6x distancefrom the rear end of model
Side surfaces - x distance from the side of model
x - length of the model
Step-11 : Once the PIDs are assigned to the surfaces of the wind tunnel, the sufaces are meshed. Top surface is meshed for 100mm, bottom surface is meshed for 20mm and the remaining surfaces are meshed for a target length ranging from 20mm to 100mm. For that spacing perimeter is used with a factor of 1.1.
Step-12 : After the surface meshing of the wind tunnel, for volumetric meshing volumes are definesd using the define tool in volume mesh.
Step-13 : The auto detected volumes are inspected and unwanted volumes are deleted. Only the volume between the wind tunnel and the model is required for volumetric meshing.
Step-14 : The volumetric meshing is done using Tetra CFD meshing.
LEARNING OUTCOMES
By doing the above meshing of the model following tools were able to practise and understand
1. Geometry checks manager to check the errors
2. Creating new faces and surfaces using fill hole and faces new tool
3. Removing small and unwanted surfaces using face cut tool
4. Assigning PIDs to the various parts of the model
5. Surface isolating tools sunch as OR, AND, NOT, !NOT, ALL, INVERT, LOCK, NIEGHB was used
6. Visibilty tools such as Macros, Cross etc are used in the process
7. Various other tools such as ENT, PID, SHADOW, WIRE, HIDDEN etc were also used in the excercise
8. Meshing tool were used for meshing the parts of the model using different mesh length.
9. Shell mesh recontruction is used to obtain optimum and error free meshing
10. Grids tool is used to adjust the mesh grids to remove the errors such as skweness, min length & max length.
11. Points and curve tools are used to create new surfaces.
12. Tranform symmetry is used to obtain the mirror image of the car model.
13. Volumetric tool is used to define the volume of the given model and TeraCFD elemt type is used to mesh the volumes.
14. Smooth and fix quality in shell mesh is used to get more refined surafce mesh.
RESULT
These are the meshing result
CONCLUSION
Since the volumetric meshing of the Tesla Cyber Truck model will take lot of time, I have done till the define volume. It was observed that Quality criteria plays a vital role in surface meshing. Mesh length that we apply will directly impact the processing time . Mesh will be more accurate if small target length are applied but require very large meshing time depending upon your configuration. Hence I used comparitively larger mesh length for ease the processing time.