Week 4 Challenge : CFD Meshing for BMW car

AIM:

     FOR THE GIVE MODEL, CHECK AND SOLVE ALL GEOMETRICAL ERRORS ON HALF PORTION AND ASSIGN APPROPRITATE PIDS. PERFORMS MESHING WITH GIVEN TARGET LENGTH AND ELEMENT QUALITY CRITERIA. AFTER MESHING THE HALF MODEL,DO SYMMETRY TO THE OTHER SIDE.

PRODECURE:

• INITIALLY, OPEN THE GIVEN BMW MODEL IN ANSA SOFTWARE.
  
  
• THEN, AS THE MODEL IS SYMMETRY WE CAN DELETE THE ONE OF THE HALF PART FROM THE WHOLE, BUT THE LOGO IS NOT SYMMETRY SO, WE CAN ISOLATE THE LOGO AND DELETE IT OTHER HALF ON THE BMW MODEL.
  
  
  
• AFTER DELETING IT WE CAN DO THE GEOMETRIC AND INTERSECTION CLEAN UP.
• NOW, WE CLEAN THE RED AND BLUE COONS FROM EACH PART SEPERATELY.
• NOW WE TAKE THE LIGHT OF THE BMW MODEL.
  
• HERE IN BMW  MODEL WE GOING FOR THE EXTERNAL SURFACE SO WE NOT WORRIED ABOUT THE INTERNAL PART IN THE CAR.
• HERE THE BLUE COONS ARE PRESENT BECAUSE THE OVER LAPPED SURFACE ARE PRESENT OVER THERE. SO,WE CAN DELETE IT DIRECTLY. THEN  FOCUS LAMP ARE THERE THAT ALSO WE NO NEED.
• NOW, WE MOVE TO THE GRILL 1 
  
• HERE THERE IS BLUE COONS AS SAME BEFORE SAID WE CAN DELETE IT DIRECTLY AND NOW WE NEED THE FINS SHAPE BECAUSE IT IS VISIBILE FROM OUT SIDE SO,NEED TO CLEAR RED OVER THERE, USING THE CUTTING THE SURFACE CREATING THE NEW SURFACE THE GRILL 1 IS COMFORMTABLLY COMPETED.
  
• BELOW SHOWN SNAP IS THE CLEAN UP 
  
  
  
  
• NOW WE CAN GO TO GRILL 2
  
• HERE THE BLUE COONS PRESENT IN FRONT OF THE SURFACE OF CAR.
• WE CAN DELETE IT DIRECTLY AND WE NO NEED EXTRA VOLUME OR SURFACES IN INNER SIDE OF THE CAR SO, WE CAN DELETE IT.
  
  
• WE CAN CREATE A SURFACE FROM INNER SURFACE AND DELETE IT.
  
• NOW WE CAN GO TO GRILL 3.
  
• FROM INSIDE THE GRILL UNWANTED SURFACE ARE THERE WE CAN DELETE IT.
  
  
  
  
  
• DELETE IT SURFACE
  
• FOR PROJECTING THE COONS IN THE FINS AND TO DELETE IT.
  
• WE CREATE PROJECT PLAN TO PROJECT COON ON FINS. 
  
• DELETE ABOVE  SURFACE AND CREATE THE NEW SURFACE IT BE FILLED.
• NOW WE CAN GO TO LOGO OF THE BMW MODEL.
  
  
• HERE THE OVER LAPPING SURFACE THERE SO, BLUE ARE PRESENT SO, WE DELETE IT DIRECTLY.
  
• HERE SMALL SURFACE IS IN UNEVEN SURFACE SO, DELETE IT AND CREATE IT NEWLY. 
  
• HERE IS THE INTERSECTION SURFACE IS THERE WE SOLUTE IT.
• NOW, WE CAN GO TO THE OPTICAL REAR VIEW MIRROR.
  
• HERE THERE IS BLUE COON PRESENT OVER THERE. AND DELETE IT DIRECTLY.
• NOW WE GO OTHERS RED AND BLUE COONS 
  
  
• NOW THE RED COONS ARE CLEARED.
  
• HERE ALSO, SAME RED COON AND BLUE ARE CLEARED.
  
• HERE ALSO, THE SAME BLUE COONS ARE CLEARED 
  
  
• IN TYRES ALSO THERE IS BLUE INTERSET IN RIMS.
  
• BLUE ARE DELETED.
  
• HERE ALSO A RED COONS ARE THERE NEW SURFACE IT CREATE.
  
  
  

• NOW ALL THE GEOMETRIC AND INTERSECTION ARE CLEANED UP.
• CHECK ALSO DONE ONLY SINGLE COON PRESENT OVER THE HALF OF THE MODEL.
• NOW WE GO TO MESHING, IN MESHING THE QUALITY CRITIRA IS GIVEN TO MODEL WHICH TO GET VERY FINED MESH IN MODEL.
  

MESHING:

THE QUALITY CRITERIAS:

• WARPING 
• SKEWNESS
• ASPECT RATIO
• MINIMUM LENGTH
• MAXIMUM LENGTH

WARPING

DIFFERENT BETWEEN MESH CRITERIAS AND QUALITY CRITERIAS ARE:

MINI LENGTH AND MAXI LENGTH IN THE MESH CRITERIA IS GIVEN ONLY FOR POARTICULAR PART ONLY.

BUT IN MINI LENGTH AND MAXI LENGTH IN THE QUALITY CRITERIAS ARE FOR THE WHOLE MODEL IT IS FIXED FOR THE MODEL WHICH CANNOT BE CHANGE TIMELY.

IN ABOVE BMW MODEL THE CRITERIA IS HAS PER THE CONSIDER ALL THE MESH TARGET ARE TAKEN.

1. Body - 3 mm
2. Lights - 4 mm
3. Grills - 1 mm
4. Rims and Tyres - 2 mm
5. Optical Rear view mirror - 2 mm
6. Window - 2 mm
7. Silencer - 3 mm
8. Logo - 1 mm

SO, FROM THIS MINI AND MAXI LENGTH ARE TAKEN 0.1 AND 7.THIS FIXED.

NOW, WE CAN GO THE MESH CRITERIA HAS PER THE GIVEN MESH TARGET LENGTHS.

FIRST FOR THE LOGO AND ALL GRILLS ARE 1MM SO, WE COMBINE IT.

AS THE OFF ELEMENT SHOWS SO, WE CLEAR IT BY RIGHT CLICK ON OFF NUMBERS.

CLEARING IT OFF ELEMENT ARE CLEARED 

NEXT FOR WINDOW,OPTICAL REAR WINDOW,TYRES AND RIMS MESH LENGTH IS 2MM.

THEN OFF ELEMENT ARE ALSO CLEARED.

NOW WE GO FOR THE BODY AND SILENCER ARE 3MM.

THEN ALL OFF ELEMENT ARE CLEARED.

NOW WE GO FOR THE LIGHTS THE MESH TARGET IS 4MM.

THEN OFF ELEMENT ALSO CLEARED.

WHILE DOING EACH MESHING WE SHOULD DO THE FREEZE OPTION IN ALL PARTS WHILE OTHER MESHING THE MESHING ERROR WILL ERROR TO AVOID WE FREEZE THE MESHED PART EVERY TIME.

AFTER MESHING THE ALL PARTS THE MESHED MODEL ARE

AFTER UN FREEZE ALL PART IF THERE IS ANY OFF ELEMENT IS THERE CLEAR IT.

NOW WE SHOULD DO THE MIRROR THE MESHED PART INTO OTHER SIDE.

FOR THE MIRROR THE TRANSFORM TOOL IS USED 

FORM THIS THERE IS NO GOEMTRIC AND INTERSECTION ERROR AFTER MIRROR ALSO IF THERE WE SHOULD CLEAR IT.

NOW FOR THE CREATING THE WIND TUNNEL , USING THE RELATIVE THE PIONTS ARE CREATED.

FROM ABOVE POINT THE OTHER POINT ARE CREATED. 

THE DIMENSIONS OF THE WIND TUNNEL,

'X' IS THE LENGTH OF THE CARS

• FRONT IS 4X MM
• BACK IS 6X MM
• SIDE ARE X MM FROM ANY WHERE FROM THE SIDE SURFACE.
• BOTTOM IS SHOULD NOT INTERSECT THE TYRES.

FROM THE ABOVE DIMENSION THE WIND TUNNEL IS CREATED.

THE ABOVE BOTTOM SURFACE OF THE WIND TUNNEL IS MESH WITH TARGET LENGTH OF THE 20 MM

THEN TOP IS MESHED WITH TARGET LENGTH OF THE 100MM 

NOW THE SIDE SURFACES ARE MESH BY THE LENGTH FROM BOTTOM 20 TO TOP 100 

FOR THIS WE USE THE SPACING MANUAL 

FROM THE DMIN IS THE STARTING THE LENGTH AS 20 AND THE DLIMIT IS 100

THEN SELECT THE ALL SIDE CONERS AND WHICH SHOW THE ARROW UPWARD

HERE THE DIMINESION INDICATES THE MESHED PART MESHED GRADUALLY FROM 20 TO 100 

NOW WE CAN GO TO VOLUME MESHING

FROM THIS SELECT THE DEFINE

FROM THIS WHOLE DATA BASE 

THE FIRST PART SHOW ONLY THE VOLUME BETWEEN THE CAR AND WINDTUNNEL ONLY 

ABOVE SHOW ONLY THE CAR INSIDE VOLUME SO, WE NO NEED OF THIS VOLUME BECAUSE WE NEED ONLY THE EXTERNAL ANALYSIS OF THE CAR.

SO, WE CAN DELETE IT.

FOR THE VOLUME BETWEEN THE WIND TUNNEL AND CAR IS DIFENED BY THE TYPE OF TETRA CFD. 

NOW ALL WORK AS DONE SO, IF WE DO THE REMESH THE STAUTS THE VOLUME MESH WILL DONE BUT WE CANNOT DO THIS IT GOES UPTO 2 DAYS IN THE SUPER COMPUTER 

AS WE DON'T HAVE HIGH CONFIGURATION COMPUTER CANNOT DO THE VOLUME MESH.

RESULT:

AS PER GIVEN MODEL THE GEOMETRIC AND INTERSECTION IS CLEANED UP AND MESHED AS PER THE GIVEN TARGET LENGTH AS PER GIVEN LENGTH EACH PART IS DONE,WIND TUNNEL ALSO CREATED AND MESH.

LEARN OUTCOMES

• SYMMETRY TOOL
• QUALITY CRITERIAS
• MESH CRITERIAS 
• FREEZE AND UNFREEZE 
• RELATIVE POINT CREATION
• IMPROVE  THE OFF ELEMENT LIKE RECONSTRUCT, RESHAPE,SMOOTH,FIX QUALITY.
• SKEWNESS 

THE ANSA MODEL OF THE BMW MODEL IS SHOWN BELOW:

CLICK HERE FOR DOWNLOAD THE BMW MODEL