Project 1 : CFD Meshing for Tesla Cyber Truck

Aim:

to check and solve all geometrical errors and Assign appropriate PIDs and also to Perform meshing with the suitable Target length and element Quality criteria.

Given:

they intended to take the quality criteria of week four and target lengths as our own ,thus i'm intended to take target lengths and quality criteria same as week four.

the target lengths taken are

• body  : target length=5mm

• window target length =2 mm

• tyres  target length= 3mm

Also as per video skewness limit will be 0.5.

procedure:

The following were the stages to perform 

initial setup

Topological cleanup 

check for errors

assigning PID's

component wise surface mesh

creating wind tunnel

surface meshing wind tunnel

Volumetric meshing the whole components 

Initial setup:

we need to import file in ANSA interface

we need to perform topo for full model in order it only seems to have only single cons 

close all the openings in surfaces by creating new faces

then our model will be completed

initially we are going to work on concept there should be a common volume inside car so we going to delete all the extra volumes or partition inside car 

inorder to do that we are tend to divide our car into two halves by using cut option on faces

then we are about to delete one half of the part by using delete option for half of entities by box selection on left view

then we get like 

 

now we are about to solve all the unwanted volumes inside car like shown

initally we take alone the body

then we tend to solve  it

after solving please be sure that no triple and single cons are present 

middle single cons will be solved while performing symentry

as we observe that there is no extra components or partition . hence we proceed with other parts

before doing that go to checks>>checks manager>>pre mesh check>>execute to see if there is any issue in model

now we are done with topo clean up and we further need to proceed with assigning PID's

the list as follows

body  : target length=5mm

window target length =2 mm

tyre target length= 3mm

assign the different PID's

window:

initially click on window PID and click show only

go to mesh parameters give type as tria and length as 2mm and save as window PID 

go to quality criteria 

enable skewness; min and max lengths and angles and thier type as fluent

give min length as 1mm and max length as 3mm

and skewness value as 0.5 and save as quality criteria

go to mesh deck click on perimeters>>length select all >>2mm>>ok

and also macros>>select all>> 2mm>>ok

go to mesh generation>>free mesh>> visible

click on hidden mode to see if there is any off values present

if there is any use grid>move option to solve it by trial and error method

tyre

initially click on tyre PID and click show only

go to mesh parameters give type as tria and length as 3mm and save as tyre PID 

go to quality criteria 

enable skewness; min and max lengths and angles and thier type as fluent

give min length as 1mm and max length as 5mm

and skewness value as 0.5 and save as quality criteria

go to mesh deck click on perimeters>>length select all >>3mm>>ok

and also macros>>select all>> 3mm>>ok

go to mesh generation>>free mesh>> visible

click on hidden mode to see if there is any off values present

if there are many offset like thousands go to shell mesh >> reconstruct >>select all>>select arrow mark on dialog box>>it will perform possible combination to reduce off values

if there is any use grid>move option to solve it by trial and error method

body:

initially click on body PID and click show only

go to mesh parameters give type as tria and length as 5mm and save as window PID 

go to quality criteria 

enable skewness; min and max lengths and angles and thier type as fluent

give min length as 3mm and max length as 8mm

and skewness value as 0.5 and save as quality criteria

go to mesh deck click on perimeters>>length >>macros >>select all >>5mm>>ok

and also perimeters>> select all but deselect the nodes which are in contact with window pid's >>5mm>>ok

go to mesh generation>>free mesh>> visible

click on hidden mode to see if there is any off values present

if there is any use grid>move option to solve it by trial and error method

symentry:

then go to transform>>copy>>select entities>>symentry>>3 point mirror plane>>select three points>> ok >>finish

to get full model of car

check for any unmeshed surfaces amd mesh them as well

wind tunnel:

now in topo deck got to points>>relative >>select bottom middle point of car>>give length as -400  in dz

which creates point on surface of tyre 

for creating wind tunnel take length of car as x 

there should be 4x distance on front of car and 6x distance on rear and height should be 3x from car top and also x distance side ways

here length of car is 6000 approx

hence x=6000

select points>>relative >>select created  point and give dy value  as 27000>>ok

repeat the steps and give dy value as -39000

repeat the steps and select the two points and give value as dx= 3900

repeat by dx=-3900

now we can see that there is points forms plane

then click on curve>>select from point to point  to create a box

then select points>>relative>>select top point of car >>give distance dz=6000

create faces>>new>> select curves>>which creates faces

click faces>> offset>>click on face>>give value thhat ismeasured between point and faces

which shows like having car in between two faces

close other fourcorners of faces by creating new faces

create PID's like base;top;side;front and rear

assign it particularly

mesh top face as 100 target length

and bottom face as 20 target length

now we are left with four faces 

here concept is there is a change in target lengths so we cannot mesh by same mesh length

so perimeters>>spacing>>geomentry >>dstart is 20; factors as 1.1 and dend is 20 >>select four nodes>>which create perimeters in variable spacing 

like we can observe there is change in length for continous nodes

then mesh other faces generally 

now we have completed all surface meshing

here we can observe that mesh on bottom is dense like  land and mesh on top will like larger due to represents air 

now go to volume mesh deck>>define >>whole db

see the list and select all the unwanted volumes and delete them 

here we need only volume between tunnel and car

now go select all entities >> tetra cfd mesh >>ok

it will take some time for 2 days

after that we are done with project

result:

thus we performed volumetric mesh in tesla cyber truck 

for model refer to  google drive link 

https://drive.google.com/file/d/1fqZQm0fwJ8zm6Az8U1UzLKtvm2OcVIfr/view?usp=sharing