Week 3 Challenge : CFD meshing on Turbocharger

For the given model, check for the geometrical errors to make appropriate volumes. Create and assign PIDs as shown in the video. Perform surface mesh with the given target lengths as per PIDs.

1. Blade stage-1 = 1 mm
2. Blade stage-2 = 1 mm
3. Impeller = 2 mm
4. Shaft rotor = 1 mm
5. Turbo casing = 5 mm
6. Compressor casing = 5 mm
7. Inlet casing cover = 5 mm

Perform Volumetric mesh for the required volumes as shown in the videos.
Write a detailed report on your surface meshing & Volume meshing process.

AIM:
This project aims to mesh a turbo charger for conducting CFD analysis.

STEPS:

1. Import the CAD model
2. Display setup
3. Geometry check-up
4. Creating the PIDs
5. Defining the Element size or length
6. selection of meshing type

OBJECTIVE:

The main objective of the given challenge is to perform surface mesh and volume mesh on turbo charger and also geometry clean up with the surface mesh for the PID's as

Blade stage-1 = 1 mm

Blade stage-2 = 1 mm

Impeller = 2 mm

Shaft rotor = 1 mm

Turbo casing = 5 mm

Compressor casing = 5 mm

Inlet casing cover = 5 mm

STEPS TO OPEN A FILE IN ANSA

• Click on File
• Select Open
• Select File (FORMAT .igs/SLDPRT .ansa etc.)
• Click Open
• A translator window appears CLICK OK

As the part gets opened in ANSA, firstly it is in wire mode and in entity mode, for desirable visualization we have to change it to shadow mode (It is the visualisation of the part in solid 3D) and the ENT Mode to PID Mode.

As we change it to PID Mode we need to change the colour of the edges in model for desirable visualization as for this we need to follow the following steps:

1. Steps To Change The Colour Of The Edges In The Model

• Go to Quality criteria option (F11)
• Select the tab Presentation Parameter
• Under visualisation option select Draw CONS in PID
• Click Apply then click on ok.(Now the edges will be in yellow colour ).

1. Checking The Geometry of the Model

• Goto checks option
• Select Geometry
• An information box will appear
• Click on execute to see the error though it should show no geometrical error for perfect meshing .

as we can see the geometry has errors. we need to clean up the exterior and interior errors. We start with assigning PID colors to the components using the product manager in the top menu.

We can see the purple glitching on the green surface. This means that there are 2 surfaces overlapped on each other at that location we use the PID selection to select that and delete. We use the basic methods like create faces to eliminate all the single cons.

For creating the volumetric mesh. We need to seal the region where the fluids flow, Hence we close all the inlets and outlets.

To mesh we should ensure that there are no single cons. Single cons indicate an opening. Once we seal all the openings the wireframe mode of the geometry will look like this.

The blue circles indicate triple cons. These cons are not errors and are required to make the geometry water tight.

Before going into meshing we just check the geometry for any errors apart from triple cons. This can be done using the ANSA check manager in the top toolbar.

Assinging relevant PID's:

Click on Surfaces > Set PID > click on surface that you want to assign a PID and also make sure that wire option is enabled

Left click on surface to select it and click middle mouse button to assign a new PID to your selected surface

Repeat the same process to assign PID's for remaining surfaces

For creating the volumetric mesh. We need to seal the region where the fluids flow, Hence we close all the inlets and outlets.

To mesh we should ensure that there are no single cons. Single cons indicate an opening. Once we seal all the openings the wireframe mode of the geometry will look like this.

The blue circles indicate triple cons. These cons are not errors and are required to make the geometry water tight.

Surface Meshing:

Select the MESH module button > parameters > length

Drag the cursor to cover the entire model and click middle mouse butto to give the mesh size as 5mm for entire model

Select Mesh generators > Free mesh and drag the cursor to cover the entire model and click middle mouse button

The entire model is meshed with size of 5mm

Similarly Meshing of individual components is done according to th given requirements

Blade stage1 = 1mm

Blade stage2 = 1mm

Impeller = 2mm

Turbocasing = 5mm

Compressor casing = 5mm

Shaft = 1mm

Use the same procedure as of 5mm and apply to individual parts

Use the same procedure as of 2mm and apply to individual parts

Use the same procedure as of 1mm and apply to individual parts

FINALIY

We can see that at the place where the shaft meets the components having different target length. The mesh adapts such that there is a connectivity between the two components.

We can see that the mesh has total 924506 components. All triangles and no quads. This means that we have meshed our geometry correctly.

Volume mesh

For generating a volumetric mesh we go to the right side menu and in the volume tab > Define > use the entire database and press ok.

It should detect a total of 8 volumes. In those 8 volumes we need only 4 volumes. These volumes are the thickness of all the components.

It should be as shown

using tetra cfd mesh to meshing the unmeshed surface

Once the required volumes are extracted we right click on these volumes select remesh and select tetra cfd. This generates 1287717 volumes all tets as shown.

CONCLUSION:

The given geometry is volumetric meshed to have 1287717 tetrahedral elements. All the elements have been surface meshed while only the fluid regions have been volumetric meshed.

And attacted the my project in the google drive in this link

https://drive.google.com/file/d/1JUKYr2MMv0_flUFene7AKMaD1nyjvRcO/view?usp=sharing