Week 3 Challenge : CFD meshing on Turbocharger

https://drive.google.com/drive/folders/1Yp5uyyFqfROItnBWTtCLFIGEHEmmSLxA

Aim: Perform volumetric mesh on Turbocharger

Objectives:

1. To check for the geometrical errors to make appropriate volumes.
2. To Create and assign PIDs.
3. To Perform surface mesh with the given target lengths as per PIDs

1. Blade stage-1 = 1 mm
2. Blade stage-2 = 1 mm

• Impeller = 2 mm

1. Shaft rotor = 1 mm
2. Turbo casing = 5 mm
3. Compressor casing = 5 mm

• Inlet casing cover = 5 mm

Procedure

Step 1. Import the geometry and create the new faces

TOPO- faces-new face option or Fill hole depending on the type of Surface

Step 2. Check the mesh

Checks Manager- Geometry check (we observed geometrical and intersection errors).

We observed some overlapping surfaces (need to delete), triple cons, and single cons errors that need to be solved. Figure 1 shows a clear wireframe model without triple cons, single cons errors. Figure 2 represents the Wireframe model of blade stage 1 and blade Stage 2 and Fig. 3 for clean geometry representation of the overlapping Surface.

Fig. 1 Wireframe model without any overlapping, single cone and triple cone error

Fig.2 Wireframe model of blade stage 1 and blade Stage 2

Fig.3 Wireframe model for clean geometry representation

Step 3. Select the rename the one PID as shaft, then apply and select all shaft components.

Step 4. To delete the unnecessary PID, select the compress option

Step 5: Close the opening to generate the control volume and check whether they in attached with respective PIDs

Select TOPO

Meshing

(Note: Watertight model: We will go with watertight mesh means there should not be leakage through mesh. )

Step 6: Mesh parameters- minimum target length and maximum target length

Step 7: Mesh- Spacing – Auto CFD for parameters and Macros

Step 8: Mesh generation- CFD-Visible

To solve this problem, select unfreeze option and select the geometry

Step 9: Select PID- CFD mesh- Perimeters- Spacing Auto- CFD Visible- Freeze option to freeze the meshing for those components. After completion of Surface, mesh go for the volume mesh, but before that, remove the freeze mesh condition.

Generate the volume mesh (Fig. 5-

Step 10. Volume mesh- define

Step 11. As we need the volume of the fluid domain, therefore delete the volume occupied by the Solid parts. Then define the type of mesh –Tetra CFD and re-mesh

Learning Outcomes

1. For new face creation-
2. Can able to find the errors, both geometrical and intersecting errors, and able to remove those errors.
3. Able to remove/ delete Overlapping surface deletion utilizing Project Option
4. Able to generate the mesh of defined target length, both Surface mesh an Volume mesh

Result:

We gave the meshing for perimeters common to two components, resulting in an unmeshed region. If provided with the free mesh, it gives very fine mesh (Fig.4), which is not required. Figure 5 shows the surface mesh generated for various components.

Fig. 4 Surface mesh with free option

Fig. 5 Surface meshing of various components

Fig. 6 and 7 shows the volume meshing with tetras and cut section of model showing the volume mesh, respectively.

Fig. 6 Volume mesh

Fig.7 Cut Section of the volume meshed model

Conclusion

The second useful for understanding on the surface mesh and volume, mesh generation. For various components, target lengths were used, which helped to analyze the flow behavior within the turbocharger.