Turbo

Objective:

To learn how to clean the given geometry and mesh it as per the volume of the turbocharger.

Procedure:

1. First import the model from the system and while opening the ANSA software choose the CFD option from the layout menu.
2. Next thing we have to do is eliminate the single cons and those gliching parts (two parts overlapping).
3. Select the crossed hatches option and by using not option hide the upper surface of the gliching part, use the delete option and select PId region tool and clean the under part of the geometry.
4. Coming to the second error that is the single cons which are seen by the red lines around them. to eliminate this go to faces=>new=>loop option on the bottom=>click on the single con=>fitted option til appropriate option is avaliable=>click the middle mouse button and face will be created.
5. To clear this error no previous ways can clear it in order to do so we have to perform a diffent procedure where in we have to create hot points. To do so go to options Hot points=>parametrical=>edge from where hot point has to be placed=>put 0.5 in the dialogue box and make selection. DO this procedure on the other side of the structure aswell.Try out creating surfaces we can notice intersection so to remove that create two more hot points following the same procedure.
6. Now create the surface using tools surface=>coons=>ENT option=>place where surface has to created as shown in the figure. Do this procedure on the right hand side of the structure aswell to obtain this figure and fill the remaining single con in the figure using the Faces=>New=>coons=>the single con=>click the middle mouse button for confirmation.
7. Now we have to isolate this surface to do so go to Cons=>project=>select con=>Select face to have a split. Now to perform deletion process select faces=>topo=>edge of the half ring=>make selection to create a tripple con.Now delete the extra part to obtain this figure
8. Now holding Ctrl+Shift check for any remaining single cons and we obtain a single con over here ,to delete this, follow this procedure- Faces=>Intersect=>first surface=>second surface=>confirm the selection, now delete the surfaces shown in the figures to obtain a clean structure Now check the geometry using Ctrl+Shift buttons and we can find only double cons and one tripple con as in the fig..
9. Now we have to set PId to the Turbo structure and we can to so by following this procedure- Faces=>Set PId=>surface to be named=>new=>shell property=>rename=>give name accordingly.
10. THe shaft assenmbly has to combined as to have different PIds but single volume in order to do so selet this assembly .
11. Go to the impeller side and create triple cons at the shown place by using options - faces=>topo=>edge of impellerand shaft=>middle mouse button and we get triple con but there is error over there i.e to clear this error go to Faces=>Cut=>join all the points one by one to obtain this- .Now there are two faces at the triple con one from the impeller and one from the shaft ,delete the faces to obtain the volume required..
12. Now coming at the three blades parts, create a triple con at the edges as shown in the figure select \'not\' option=>PId region=> middle mouse button and we obtain this make selection and delete these extra faces. Now isolate the 4 blades and follow the same process and delete these faces that are shown inthe figure- .
13. The error now visible is the glitch at the blade to remove this go to Cons=>project=>select the con=>select the face=>middle mouse button and you obtain this structure- .You can observe the difference in the geometry this is due to meshing to remove this go to mesh=>perimetre=>length=> select this part shown in the figure- =>copy the parameter of the adgecent part=>middle mouse button and make a triple con by going to faces=>topo=>middle mouse button.
14. As there is a triple con we can delete the extra part so as to obtain required volume now delete the face in between- using the previous process delete the face to obtain this-. do this to both the sides and now we can see that there is a single volume for the shaft assembly-.
15. As every error is deleted now we have to compress the structure which will help to remove unwanted parts of the structure, to do so go to Compress=>all deck=>ok this will delete the unwanted parts.
16. Now the structure has to meshed to do so go to mesh=> Perimeter=>length=>Selet the entire geometry=>5mm=>click ok=>mesh generation=>free mesh=>tria,reconstruct=>select he whole geometry.
17. Each part has to meshed with different length so to do so :now we have to erase the mesh by using the erase option in the mesh generation tab.
18. Go to properties and select the parts one by one and give length accordingly , Blade stage 1,Blade stage 2,Shaft rotor all should be of 1mm; Impeller should be of 2mm;Turbo casing,inlet casing cover,compressor casing all should be 5mm.this can done by using the previous used process. at the end check that all parts are meshed if not meshed ,mesh them using the free mesh option.
19. Now we can see that there is a glitch at the shaft and the casing and that should be removed to do so go to faces=>delete=>the part to be deleted=>ok .now we can see that there is a single con left behind .Now the single con has to be removed so go to Cons=>project=>split original curve,paste,connect with faces=>loop option=>the single con=>face of the shaft=>click ok.Do this to all the parts where the glitch took palce , you will get the follow in result .
20. Now the previous meshed part is not meshed because of the newly deleted glitchs.now to mesh the parts again the rotor shaft has to be defined with length again and meshed afterwards using the previous process.
21. Now we can see that there is a noticiable difference in the mesh of the shaft and the casing to reduce this we can create a small area where in we can give mesh of intermideate valve so that the mesh is gradually reduces,to do so follow this process- Macros=>cut=>join the points around the shaft in a closed loop manner as shown in the figure- =>perimeters=>length=>select the new area =>3mm length=>click ok. Do this on the inside as well as shown in the figure-.
22. To create a volumetric mesh the structure has to be closed so we have to close the etries and exits. Close the Inlet and outlets of both the casings as shown in the figure- Set PIds for the parts and mesh these newly created parts.Check that there are no unmeshed parts if there are mesh them accordingly.
23. Now the volume mesh has to be done to do so go to V-mesh on the top and select the following options - Define=>whole.db=>Click ok.
24. Delete the unwanted volume and keep only the volume required;the required parts are shown in the figure-
25. To volume mesh go to unstructured mesh=>Tetra CFD=>Volumes=>select the parts =>click ok and you a meshed figure as shown in the figure-.
26. The inside of the mesh looks like the following figures- , , .

Outcome:

We come to know about the volume meshing of a geometry and learn minute details about surface meshing and learn to rectify the problems faced during the meshing.

Conclusion:

The turbocharger given to us is cleaned appropriately and volume meshed as per the requirement.