Project 1 : CFD Meshing for Tesla Cyber Truck

REPORT:

Aim: To Perform surface mesh and Volumetric mesh on tesla cybertruck.

Objective:

To perform:

• geometry cleanup
• assigning PIDs
• surface mesh
• create wind tunnel
• volumetric mesh

Procedure:

1. Geometry topo cleanup and PID Creation:

• The geometry is imported to ANSA software.
• understood the geometry.
• model looks symmetric as then it divided longitudinally into two parts and deleted one side.
• check the errors and over lapping faces.
• isolated each parts and cleared the errors and deleted over lapped faces.
• created model as one volume.
• closed the geometry by deleting and creating new faces.
• isolated each parts using 'not' command to assign PID's using PID manager as follow

1. body
2. lights
3. tyres and rims
4. windows

2. Surface Meshing:

• to create surface mesh on each PID.
• lets consider the PID windows to create surface mesh.
• windows are isolated using Not(PID) option or also can be isolated from PID manager as well.
• opened mesh quality criteria and entered the value of min length (i.e. 3 mm) and max length (i.e. 7 mm).
• opened mesh parameters and enter targhet length (i.e. 5 mm) and also min and max target length value.
• selected element type as tria.
• from perimeters menu selected length and assign perimeters and macros to windows PID.
• then created spot mesh on isolated PID.
• followed the same procedure from every PIDs.
• Target lengths, min target length and max target length for each PID is shown below.

• Sl.No.	PID's	Target length	min length	max length
  1	body	5	3	7
  2	lights	5	3	7
  3	windows	5	3	7
  4	tyres and rims	5	3	7

• then use transform - copy tool using 3 point mirror option to create same half on other side.
• selected as same part at zero offset.
• selected 3 points and clicked middle mouse button.
• perform topo to check cracks and single cons.
• 

3. Creating wind tunnel:

• for creating wind tunnel, one point is reffered at the middle of bottom surface and plotted one point exactly downwards at a distance of 530 mm using relative point option from the reffered point.
• suppose length of cybertruck is x mm which is =~6000 mm for the provided cybertruck model.
• we need to plot one point from front side of model at distance of 4x from most front point of cybertruck model.
• the most front point of model is at distance of 2500 mm and the most rear point of model is at distance of 3500 mm from newly plotted reffered point.
• so the front point will be at (24000+2500)= 26500 mm distance from reffered point.
• we need to plot one point from rear side of model at distance of 6x from most rear point of model.
• so the rear point will be at (36000+3500)=39500 mm distance from reffered point.
• then plotted points on both the sides of both rear and front point at a distamnc of (1x) 6000 mm.
• created curve to join all the four corner points(straight lines) to create surface.
• then surface is created below the model.
• then extra points and curves are deleted from that surface by hiding model and below surface.
• the same surface is copied straight above the model at a distance of 20500 mm ( 3x + height of model).
• then surface is created using fitted from new faces from all the sides of model reffering those two surfaces.
• then created PIDs as

1. basesurface_tunnel
2. topsurface_tunnel
3. frontsurface_tunnel
4. rearsurface_tunnel
5. sidesurface_tunnel

• and then assigned PIDs to each side.
• then mesh base surface with target length = 100 mm, min length= 80 mm, max length= 120 mm and top surface with target length = 500 mm, min length= 450 mm, max length= 550 mm by the same procedure used for windows PID.
• Then used spacing command for side, front, rear side PIds and assigned spacing from bottom to top from 100 mm to 500 mm with factor of 1.1.
• then generated spot mesh on every PID one by one.
• 
• 

4. Volumetric Meshing:

• selected volume mesh deck.
• In that selected 'define' command from volume deck and selected detect on as on whole data base.
• got automatically generated volumes.
• from that volumes, deleted unwanted volumes which are not supposed to be meshed and keep only one volume which is between cybertruck model and tunnel.
• then we should use 'Tetra CFD' type mesh on required volume.

Results and conclusion: model is well studied and understood, PID's are assigned. surface mesh is done with required target lengths. volumetric mesh is carried on required volumes.

Google drive link for file: https://drive.google.com/file/d/1hihh09Sq9JDVMFCThmo6rgfzRzqDh_qp/view?usp=sharing