Week 4 Challenge : CFD Meshing for BMW car
AIM:- To Perform CFD Meshing for BMW car.
OBJECTIVE:-
For the given model, check and solve all geometrical errors on half portion and Assign appropriate PIDs. Perform meshing with the given Target length and element Quality criteria. After meshing the half model, Do symmetry to the other side.
Target lengths for the different parts of a model are as follow:
- Body - 3 mm
- Lights - 4 mm
- Grills - 1 mm
- Rims and Tyres - 2 mm
- Optical Rear view mirror - 2 mm
- Window - 2 mm
- Silencer - 3 mm
- Logo - 1 mm
PROCEDURE:-
importing the geometry :-
PID mode
topo clean up done for the geometry
ENT mode
single cons present in the geometry (wire frame mode )
we can see the some surface of the model is not having prefect shape this we need to correct
to make surface much more finer we have to go to the meshing mode in that we need to select the length option and set the perimeter and macro length to 1mm and come back to topo mode see the much more refuned surface of the geometry
model as been cutted in half for correction
all the single cones are cleard in grilled area after removal of unwnated surface and hot points
logo area has been clened from single cons and triple cons
next step is to remove the unwanted surface from the window area
gril part as been cleared from single and triple cons
tyre geometry clean up done and geometry check up done for cones found okay.
all the geomatry clean up done and removed all the single cons and double cons from the body except in the cutted region.
after clearing all the single and double cones and geometry check up this all the error arised. (we need to solve only triple cons)
clearing all the triple and collapsed cones we get below geometry
named selection after asigning the pid to different region we have deleted all the unwanted pid using compressed option
MESHING THE SURFACE
quality critera
LOGO:-
meshing the logo with target length 1mm. min length 0.1 mm and max length is 2mm
SCILENCER
meshing doen to scilencer with target length 3mm
WINDOW
meshing doen to window part with mesh target length 2mm
rear view mirror
meshing done to rear view mirror with 2mm target length.
RIMS AND TYRES
meshing of rims and tyres are done with mesh target length 2mm
GRILLS
meshing of grill is done for a target length of 1mm
LIGHTS
meshing of ligths done with the target length of 4mm.
CAR BODY
meshing as done to the car body with mesh target length 3mm.
after meshing the whole body of the car we have able to get the 469378 tria elements
after doing symmetry for the selected body and solveing all the single cons we have this below model
after completing the meshing we need to do checking for the geometry for any single cones and triple cons. but we can see that from the geometry check there is no error.
wind tunnel creating
we need to create a wind tunnel for the the car body the buttom surafec is just below the body, the top surface is 3X times the whole length of the car body (1300mm) , the front surface is 4X times the car length, and back surface is of 6X the car length.
all the sides of the wind tunnle faces are created.
PID as assined to all the surfaces
we need to asign the top surface with the value 100mm mesh length and the buttom surafec is set to 20mm mesh length, for the front and and back surface we have to set the spaceing option to do the step increse of the mesh length over a tunnel.
below figure shows the spacing parameters
we have isolated the buttom face and done with the mesh target length of 20mm
top surface is isolated and meshed with the target length 100mm
spacing is used to jsut to stady the surroundung area around the car body
volumetric meshing
after doing all the steps we need to do volumetric meshing for the whole. after doing the auto detect we have found that below mentions undifined unmeshed parts in this we need to delet the unwanted volume
after deleting the unwanted volume we have left with this below shown volume.
MODEL LINK :-
https://drive.google.com/file/d/1NuW8xf82t-9-k3xdLvlSosj3F2pI6-z2/view?usp=sharing