Week 3 Challenge : CFD meshing on Turbocharger

Aim: CFD Meshing onTurbocharger

1. To Check for the geometrical errors to make appropriate volumes for the given model.
2. To create and assign PIDs for the various components of the geometry.
3. To perform surface mesh with the given target lengths as per PIDs.

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

                      Note:

                                . To Perform Volumetric mesh for the required volumes.

                                . To Write a detailed report on your surface meshing & volume meshing process.

      Procedure:

1. Patch the missed surfaces:

. First, we need to import the geometry model from the source folder.

. The geometry file contains lot of irregularities, discontinuities, so we need to patch all the missing and open surfaces in the geometry.

. This can be done by the following procedure;

                 TOPO => Faces => New => Here we can select any method => Select the cons (This can be done by entity or PID method) => Middle click or surface click

2. Removing overlapped surfaces:

             . At some areas of the geometry, we need to clear the overlapped surfaces.

             . This can be done by following procedure;

                            TOPO => Delete => Select the surface to be deleted by using entity or PID mode.

                                     . Sometimes we need t project the cons to make the single cons into triple cons.

                                     . This can be done by the following procedure;

                           TOPO => Delete => Select the surface to be deleted by using entity or PID Mode.

                                   . Sometimes we need to project the cons to make the single cons into triple cons.

                                   . This can be done by the following procedure;

                          TOPO => Cons => Project => Select the Cons => Middle Click => Select the face where the cons have to be projected => Middle click.

3. PID Assigning:

 

.

 Now we need to create PID (Property ID) for all the surfaces like inlet, outlet, spring, Column, Base and Value head.

         . This can be done by the following procedure;

                          Properties => Right click on the properties screen => New => P Shell => P Shell => Box pops-up => Name has to be given

                                         . Similarly, we need to create as many as required.

                                         . Now we need to assign the created PID’s to the respective Surfaces required and we need to makes sure that cross-hatches option is enabled.

                                          . This can be done by the following procedure;

                      Properties => Right Click on the PID => Apply => Select the cross-hatch present in the surface of the geometry => middle click on the mouse.

                                           . Similarly, we need to do for all the required surfaces.

   Fig .

4. Surface mesh process:

                                . Now we need to mesh the geometry.

                                . This can be done in two ways.

1. Meshing the whole geometry in one shot. (Only with single element length can be done at a time)
2. Meshing the geometry part by part individually. (Each part or component can be given different element length)

. The first method is employed in this challenge, however the second is highly beneficial when meshing distinct pieces with varying target lengths.

. Meshing can be done by following procedure;

                       Mesh (Right side on the screen) => Perimeters => Length => perimeters => Give the target length => ok

                       Mesh (Right side on the screen) => perimeters => length => macros => give the target length => ok.

Fig …………

                       Mesh Parameters (Top of the screen) =>Give the target length, min and max length in that dialog box.

                       Quality Criteria (Top of the screen) => Give the target length, min and max length in that dialog box.

Fig…..

                       Mesh Generation (Right side on the screen) => Spot mesh => Select the geometry to be meshed.

Fig…

5. Volume Mesh process:

          . Now we need to move to volume mesh.

Volume => Define => Work on => Whole db

    . Now we need to drop volume mesh to the geometry.

    . This can be done by following procedure:

                      Volume => List => Here we need to select the component to do volume mesh => Right Click => Re Mesh => Fluent Method.

Fig......

                      Conclusion:

                             . The above figures are surface, volume mesh of all the components in the geometry

                             . The last two pictures show the cut section of the volume mesh.

                             . We may also deduce from the final two figure that the shaft, first and second stage blades have 1mm element sizes, while the compressor casing has a 5mm element size, resulting  in a transition from 1mm to 5mm, as shows in the diagram.

Fig

Solve the Turbocharger ansa.

Properties

              TOPO Clean-up: overlap bleaching