Week 3 Challenge : CFD meshing on Turbocharger

AIM:

For the given model, check for the geometrical errors to make appropriate volumes. Create and assign PIDs. 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.

OBJECTIVE:

• Check for the geometrical errors to make appropriate volumes.
• Create and assign PIDs.
• Perform surface mesh with the given target lengths as per PIDs.
• Perform Volumetric mesh for the required volumes

PROCEDURE:

TOPOLOGICAL CLEANUP & PID ASSIGNING

1. Under checks- geometrical checks- template-ANSA[AUTO GENERATED TEMPLATE]-visible
2. Found out several locations of single cons and filled with appropriate fills.
3. In several locations during topo cleanup, intersect and faces and delete where used to convert single cons.
4. In some locations single cons were converted to triple cons by using TOPO.
5. In curved locations, multiple hotpoints was created using parameteric option and connected by coons in faces.
6. Single Cons to triple cons using TOPO.
7. After topocleanup PIDs were assigned.
8. It is necessary to fill all gaps for volumetric meshing. So fills where done to avoid leakage in CFD analysis.
9. All PID’s name is given.

SURFACE MESHING

1. 5mm meshing carried out for turbo casing, inlet cover casing and compressor casing.

5MM TARGET LENGTH

1. Select Mesh parameters and set target length as 5mm and Select Quality Parameter and set minimum length as 3mm and maximum length as 7mm.
2. Select Mesh deck and and select mesh parameters by selecting CONS of each PIDs and set length as 5mm and select macros and set as 5mm.
3. Now select spot mesh and select face and middle click on mouse to see the meshes.
4. Continue for each PID’s by NOT, Neighbour, All, AND, OR options in visibility tab.

2. 2mm meshing carried out for impeller.

2MM TARGET LENGTH

1. Select Mesh parameters and set target length as 2mm and Select Quality Parameter and set minimum length as 1mm and maximum length as 3mm.
2. Select Mesh deck and and select mesh parameters by selecting CONS of each PIDs and set length as 2mm and select macros and set as 2mm.
3. Now select spot mesh and select face and middle click on mouse to see the meshes.
4. Continue for each PID’s by NOT, Neighbour, All, AND, OR options in visibility tab.

3. 1mm meshing carried out for blade stage 1, blade stage 2 and shaft rotor.

1MM TARGET LENGTH

1. Select Mesh parameters and set target length as 1mm and Select Quality Parameter and set minimum length as 0.5mm and maximum length as 2mm.
2. Select Mesh deck and and select mesh parameters by selecting CONS of each PIDs and set length as 1mm and select macros and set as 1mm.
3. Now select spot mesh and select face and middle click on mouse to see the meshes.
4. Continue for each PID’s by NOT, Neighbour, All, AND, OR options in visibility tab.

VOLUMETRIC MESHING

1. Click on V.Mesh and define volumes.It was noted that 9 volumes is autogenerated.
2. Out of all volumes, 4 volumes where found to be perfect suited for CFD analysis.
3. Now each Volume is assigned PID and TETRA CFD meshing is done. But it was found that a leak is observed with unmeshed 1 volume. THIS WAS AN ERROR.
4. I restarted the ANSA by selecting ANSA CFD And repeated the same process.This time I was able to mesh using Tetra CFD on all four volumes.
5. Cut section of a part of Volumetric meshed is shown below.

LEARNING OUTCOME:

1. Lifelong Learning
2. Modern Tool Usage
3. Communication

RESULT:

• Checked for the geometrical errors and made appropriate volumes.
• Created and assigned PIDs to all shells.
• Performed surface mesh with the given target lengths as per PIDs.
• Performed Volumetric mesh for all the required volumes.

ATTACHMENT: GOOGLE DRIVE LINK OF WORKED MODEL:https://drive.google.com/drive/folders/1EK_tNyiiOEeVVLHOU121pkII0U28dwY3?usp=sharing

CONCLUSION:

Best results were obtained when mesh sizes were smaller, but increase in mesh elements is not appreciable as this may leade to more computation times while making volumetric meshes.