Mesh the BMW M6

Title : Mesh the BMW M6.

Objective : To remove all Topological errors and mesh BMW M6.

Methodology :

• Find all errors i.e Single coons, Triple coons, contour lines and etc.
• And eliminate error one by one.

• Eliminate the contour lines.
• Select the contour line and Delete them by using Universal delete option.

• Eliminate the single coons as show in below figure.
• delete the entire patch using DELETE option.
• And create a new surface in order to eliminate the error.

• create new surface Faces>>New>>Coons>>ok

• Another error is shown in below figure.
• so to eliminate this error follow the steps.
• Extend the surface till next face.
• Faces>> extend>> select lineto extend>>select face till extend.
• then Intersect faces.
• Faces>>intersect>>slect face one>>select face 2.

• Then Rotate the model and Again intersect Two faces.
• Faces>>intersect>>select face one>>select face 2.

• Delete all othe unneccesay parts.
• Faces>>delete>>select.

• Then Create New Face using Faces>>New>>Fitted.

• Once the surface has been created , Project the curve on surface to get the Double coon.
• But some times Project Command does\'nt work, so instead of Project Try Intersect command.
• Faces>>intersect>>select face one>>select face 2.

• Once this is done, Delete All other Uneccesary surface. And create new surface in order to patch using Faces>>New>>Fitted.

• Once this done we notice Triple con, so over Come it
• First Release the triple con and then Paste the coon , to get the desired double cons.
• Then Patch all the missing faces of car body.
• once this is done we notice a triple con on windows, front windsheild and back windsheild.

• This is because of excess volume is created while modelling.
• so to overcome this , Delete the excess volume of all windows and wind sheilds.

• Now we have to fix the Logo of BMW.
• Project the logo on hood surface.
• then delete the inner/lower surface of logo to get the clean geometry and double con.
• We will have delete the BMW extruded part because at the time of analyisis it will create some drag and will increase load count, so to avoid it delete the extruded geometry.
• And create Flat surface over it.

• Now we can see some glicing in Fog lamp. we have to correct the whole geometry .
• So lets delete the excess outer surface

• We will get compareively clean geometry. But, still it has lots of error so to fix it.
• Use cut command and remove excess Extrusion.
• Faces>>cut>>Select two nodes.
• Delete all excess extrusion.
• Then Patch All Fins.

• As we have clean the Left Fog lamp geometry ,Similarly we have to clean the oithe fog lamp.
• so to fix it we will use Symmetry option. And simplly just create copy of clean Fog lamp and keep it on other side.

• For this first delete the Right fog lamp, because the postion where we have perform symmetry need to be empty.
• Then use Transform tab>>copy>>symmetry>>mirror 3 points.

• Select 3 points on different planes. Finish.

• Once this is done . Paste the created Geometry cons on the exsisting planes, in orde to intersect the planes.

• As shown in the figure , Delete the half side of car.
• As the model is Symmetric later we will create the symmetry of half part after eleiminating all errors.

• Then we notice errors in Front intake Grill.
• Delete All exxess Surfaces.
• Release all triple cons, then paste the cons .
• And then project them on surface.

To eleiminate errors in above figure.

1. Project upper portion of grill on surface. cons>>Project
2. then intersect. Faces>>intersect>>select face one>>select face 2.
3. Then cut the excess extrusion.
4. Faces>>cut>>Select two nodes.
5. Delete all excess extrusion.

• Then Extend the surface by desired lenght to get complete geometry.
• Surface>>Extrude>>Glide

• Select 1st line and select end surface.
• once surface is created , to correct it Go to Mesh UI set perimeter/length .
• we will get the desired surface.

• Now to Avoid Segregation Seperate parts of model according to PID\'s.
• Go to Model Browser>>New>>Set part>>sdrag on part>>Double click on EMPTY.

• Then to distinguish parts, Save them in One folder.
• Model browser>>New>>Group from visible>>move.
• Done

• To move some part in any othee folder
• Set part>>select part>>select folder>>double click.

• Now we have to fix the Exhaust, and create Surface arround it.
• So first create Offset curve. i.e by usinf Zone cut command Facees>>Zone cut.
• Select curve to be offset, then enter length of offset and Done.
• Then delete the excess part.
• create Surface using Surface>>Extrude>>Glide.
• And patch all other surface using Faces>>New>>coons.

Then Seperate the PID\'s and group them

• Model Browser>>Pid Properties
• Click on small arrow >>Visible
• Make Group and Assign PID\'s

Then Compress all uneccesary properties using Compress tools.

Then Run Geometry Check and eleiminate all the errors.

Then Mesh the Model .

1. Body - 3mm
2. Lights-4mm
3. Tyres-2mm
4. Ovrm-2mm
5. Windows-2mm
6. Silencer-3mm
7. logo-1mm
8. elements - Triangle

• Set the perimeters one by one of given length.
• Go to MESH tab>> Perimeter>>length(set length)
• Then go to Mesh>>Free mesh>>select visible Done

Set the Mesh Parameters.

.

Mesh parameter>>Basic>>General

1. Target length= Perimeter
2. Min target length = 1(As per given)
3. Max target length = 5(As per given)
4. Distortion Angle = 15%

• Then Perform Surface Mesh Check.
• And eleiminate All the errors.

Then Check Quality .go to Quality Criteria

Enable necessary parameters to find errors like

• Skewness
• Warping
• Min length
• Max length

• Then Eliminate the Errors one by one.
• To eliminate Skewness, Go to elements>>Split OR Grids>>Mv Surf
• To eliminate Min & Max length error use Shell mesh>>Reconstruct.

• Once this is done we have eliminated all the errors.
• Then make Symmetry of one side, to get complete geometry of Car.
• Transform>>Copy>>select entities>>mirror 3 points plane>>Done

Then we will get complete Geometry of BMW M6.

Simillarly, Make Symmetry of Tyres.

• Transform>>Copy>>select entities>>mirror 3 points plane>>Done
• Then we can observe the tyre Front tyres markings are different then other .
• so to correct that

1. Delete the Tyre mark
2. then go to Transform>>copy
3. select reference point
4. And done.

• Then go to topo mode and select single coon and correct it to double con.

Once this is done we have to create Wind tunnel as per dimension

1. front windtunnel = 4x front of car
2. Rear windtunnel = 6x rear of car
3. Top windtunnel = 3x top of car
4. Bottom windtunnel = Close proximity with tyre
5. Side windtunnel = From center plane from left & right

Measue the length of car.

• then to create front wind tunnel , create point using
• Points>>Relative and give length 5200 (4x front of car)
• Simillarly for Rear, Top , Bottom and Side.

• Then create Curve in between two points using Curves>>New >> select initial and target.
• And then Create Plane on created points. But to create plane we need atleast 3 points.
• So create 2 more points respectively on Front, Rear, Top , Bottom and Side.

• Then create the plane using Surfaces>>Plane>>select 3 points. and DOne.
• Once all planes are created, Intersect them all to delete all uneccesary planes.

• Then Go to mesh mode >> assign perimeter>>length.
• For base plane Assign length of 100
• For top assign length of 20
• And for middle portion assign length from 20 to 100 using
• Perimeter>>spacing
• Assign lower limit and upper limit.
• then we will get propeer spacing in between 20 to 100.

• Finally Mesh all the surfaces.
• And we will get the desired output for BMW M6.

Result : Hence by performing all above operations we get the desired Mesh for BMW M6

.

Conclusion : From this we have learnt new techniques like

• to remove topo errors
• to remove Quality errors.
• Also we have learnt how to use symmetry options.
• Then we have also learn how to Seperate the PID\'s and group them.

Link : https://drive.google.com/file/d/1R2e16a4eQP42D9oK3mHQG-owQUnVzwpw/view?usp=sharing