Week 3 Challenge : CFD meshing on Turbocharger

Aim: The main object is to generate the volumetric mesh on a components like Turbocharger casing, compressor casing, impeller blade, turbocharger blades, etc. according to the engineering standards using ANSA software.

Introduction: Turbocharger is a device used in the internal combustion engine, which operates to compress the gas and deliver in a high speed to the engine in order to obtain more power for the required displacement.

• Turbocharger consists of casing inlet, casing outlet for the flow of gases from inlet to outlet.
• It also consists of compressor which works as to compress the air and deliver in a low-speed high pressure air which will burn in the combustion chamber.
• It also consists of impeller and blades to compress this air fluid in the compressor and in the turbocharger.

Procedure:

• Open the file in ANSA software, and check the geometry for any loop hole surface if any.
• In tools option go to check tool and select geometry tool and select single cons and triple cons and execute so that we can check if any single cons and triple cons are presented in the drawing.
• So, we are getting a number of errors so by using show only option we can see where these errors are located and we need to work on it by using some top option.
• So, there was a bleaching happen in those single cons, means there has generated two surfaces one above the other so we need to delete one surface so that single cons will not be error.

• After deleting the bleaching surface again, we need to create the surface in order to minimize the error as shown in the figure above.
• In some cases, in the drawing the new surface wont seems good by using new cons surface. In that time, we need to generate the new hot-points over the surface and generate the new surface by using the hot-points. This is because of the corner round surface which doesn’t allow to create a new surface over there.

• In order to do a volumetric mesh, the model should be a single geometry then only the volumetric mesh generated. In order do so we need to convert the model to a single geometry wherever required.
• The impeller, blades, and the shaft rotor will be in different geometry so that we can’t generate the volumetric over there. So, we should delete the unnecessary surface in between the shaft rotor and blades, shaft rotor and impeller.
• And also some bleaching is present over the shaft rotor, so in order to delete this bleached surface we need to project the those single con error on the main rotor and we can delete the bleached surface once we project this single cons.

• In between the impeller blade and shaft rotor the surface is not deleting so we should again project these single cons on the impeller and delete this surface to make a single volume though out. When we check in the wireframe mode the there should not be any errors should present over the entire volume.
• After this we need to check any bleaching’s, single cons and triple cons presented.
• Two bleaching’s are presented in between the turbo casing and the shaft rotor in the bottom, so we need to delete the bleached surface. If we delete the bleached surface we will get 2 single cons
• At this point we need to project the cons on the shaft surface and should make the topo over there by doing this we will me getting the triple cons which is needed and it won’t be an error because three surfaces are joining together. In the similar way there is a bleaching present between the shaft rotor and the impeller casing we should minimize this error by doing the same operation as we did before.
• After this we need close the any opening in the model. If any we can close it by selecting new coons’ surface and close the entire model to detect the volumes where we need to mesh it. These are compressor inlet, compressor outlet, turbo casing inlet and turbo casing outlet.
• After minimizing all the single con and bleaching errors we should assign the PID(properties ID) for the respected model and can select proper color between them to recognize the model well in advance.
• After assigning the PID’s we can now very well to generate the surface mesh before moving towards the volumetric mesh.
• As per the given requirements we should generate the surface mesh to the model.

• By changing the quality criteria for different model we should generate the surface mesh as per the requirements.

• At last we should we should each and every corner is mesh has been generated properly. Some of the surfaces are hidden so we need to hide some surfaces to check whether the mesh has been generated wisely. These surfaces are like near impeller and the shaft rotor, blades with the rotor, rotor and the casing etc.
• In some cases if it is not generating the mesh we should provide the perimeter and macros wisely to generate the mesh properly.

• At last, we should end up with zero meshed surface and should not be any error obtain before we should move the volumetric mesh.
• After surface mesh we should move to the volumetric mesh. Here in auto detect option we will obtain 8 different volumes.
• Whenever we should do a volumetric mesh, we should note that only the surface can be volume where the fluid should move in that. We should mesh the model of the thickness of the body it not helpful the analysis.
• These are the turbo charger casing, the blades, impeller blade, compressor casing, casing outlet. Out of eight volumes detected we can generate only four volumes which is helpful for the analysis.

• In order to do a volumetric, one should select the Tetra CFD in unstructured mesh option, and by selecting the volumes we need to again give the remesh option to generate the mesh inside those volumes.
• After completing all the volumetric mesh when we check the list in volumes option it should show it as the mesh has been generated to the above volumes with a Tetra CFD mesh tool option.
• After this by deselecting the Geometry and FE model option we can conquer that the mesh has been successfully generated for the given volumes.
• In order to analyses the mesh generated in the particular volumes we can hide some part of the volume using not option we can see the tetra mesh has been generated to the given volume.

• Not only a small part we can also cut the half section and can see what is behavior of the inside the volume.
• For example, in turbo casing wherever the blades are located there will be a fine mesh can be visualized and wherever there is no any disturbance there will be a very hard mesh is generated over there.

• Similarly in the compressor inside the casing due to the impeller there will be fine mesh generated and beyond the impeller there will be a very large mesh has been generated.

Learning Outcomes:

• Now we can able to check the geometry where the single cons, triple cons and bleaching is presented in the geometry.
• We now able to make the geometry a closed volume to generate the volumetric mesh.
• We now able use different tools like Tetra CFD to mesh the particular volume for the analysis.
• The tools like project in cons is very much helpful to minimize the error obtain due to single cons which than converted into triple cons.

Result:

Volumetric mesh has been generated for the given geometry with the help of ANSA software.

Conclusion:

In order to analysis any flow properties within the geometry we should first check all the loop holes in the geometry and should minimize it by top cleanup the geometry. After topo cleanup we should generate the surface mesh without any errors obtain on the surface in between. Tetra CFD is 3D mesh tool option which is used for the volumetric mesh to analyse the flow in the given geometry.

https://drive.google.com/file/d/1W9MF0IsymJBq6Elm-B7PKZLeznAwQ6fy/view?usp=sharing

**(As the file size is high i cant upload through the file upload option here so i am giving a link to check with the detailed report and the volumetric mesh model through this link.)