Week 3 Challenge : CFD meshing on Turbocharger

AIM: Eliminate the topological errors and mesh the turbo charger using ansa.

INTORODUCTION TO TURBO CHARGER:

turbocharger is a turbine-driven forced induction device that increases an internal combustion engine's efficiency and power output by forcing extra compressed air into the combustion chamber.it consists of just 3 major components they are turbine,compressor and the turbine shaft, connecting the turbine and compressor wheels together.the impeller in the turbine gets rotated by the exhaust gases passing through it, hence the shaft attaches to the impeller rotates as a result the blades in the compressor gets rotates hence the inlet air is compressed and send to the combustion chamber.

PROCEDURE:

STEP 1:Eliminating the topological errors

error 1:we delete the surface under the compressor casing.

error 2:we create the surface at the inlet of compressor casing by using the fitted option in the new face tab.

error 3:we create the surface on the turbo casing by creating hotspots using parametrical option and coons

hence all the single cons in the model are converted to double cons we now assigining the pids to the model.

STEP 2:Settings the pid's-

we just the assign the pids to the model in the properties tab to

1. blade stage 1
2. blade stage 2
3. shaft rotor
4. turbo casing
5. inlet compressor casing
6. compressor casing
7. impeller

STEP 3:Converting the individual entities into volumes-

we convert the individual entities into seperate volumes by using topo and cut tools.we delete the some entities and overlapping surfaces to make the volumes. we project the cons by using the project option.

STEP 4:Compress the model

Before meshing we need to compress the model in order to delete the unwanted faces,nodes,points empty parts and pids.

properties before compressing

after copressing the model it deleted

• faces :61
• no.of nodes :2660
• no.of properties : 2
• no.of sets :1
• no.of ansa parts :1

STEP 5:Meshing(creating 2d mesh):

we meshed the model by using free mesh tool using the element shape as tria.

The mesh length for different pids are

1. blade stage 1:1mm
2. blade stage 2:1mm
3. shaft rotor:1mm
4. impeller :2mm
5. compressor casing:5mm
6. turbine casing:5mm
7. internal compressor casing:5mm

after meshing due to difference in the mesh lengths at the intersection of shaft rotor with impeller and compressor casing and turbo casing at that intersection points the mesh is not accurate so we just create the hot points at the intersection and cut the area with length of 3units.then the mesh at the intersection tranfers from 5mm to 1mm graduall

STEP 6: 3D MESH(Creating volumetric mesh)

After completion of the surface mesh in order to create the volumetric mesh first we created the volumes at the openings asiigining pids to them and we meshed them.the volumes that are created are:

• inlet compressor casing
• outlet compressor casing
• inlet turbine casing
• outlet turbine casing

now the model is ready for 3d meshing.now we get into v mesh option and we perform volume detecting option hence 8 volumes are created as shown below

after creating the tetra cfd mesh the no.of volumes created are 9891105.

LEARNING OUTCOMES: From this project i have learn how to perform the surface meshing and volumetric meshing and gets exposed different tools in ansa.

CONCLUSION:The given model of turbo charger is made error free and a proper volumetric meshing is created while a total of 9891105volumes are created.