Meshing of car Engine Intake Manifold using ANSA
AIM :
To check for geometrical errors in the given component (Engine Intake Manifold) and mesh it using tria/ortho tria elements on the surface and tetra elements to fill the volume.
THEORY :
In automotive engineering, an intake manifold or inlet manifold is the part of an engine that supplies the fuel/air mixture to the cylinders. The word manifold comes from the Old English word manigfeald and refers to the multiplying of one (pipe) into many.
The primary function of the intake manifold is to evenly distribute the combustion mixture (or just air in a direct injection engine) to each intake port in the cylinder head(s). Even distribution is important to optimize the efficiency and performance of the engine. It may also serve as a mount for the carburetor, throttle body, fuel injectors and other components of the engine.
PROCEDURE :
- The CAD model is imported in ANSA.
- The face orientation is done. Topology and geometric cleanup is performed to remove any surface irregularities.
- In order to reduce the complexity of mesh, small areas are defeatured by uncutting unnecessary cons.
- In order to account for the minimum length criteria, the DACH divide operation is performed at some fillet regions.
- After the geometry cleanup, the body is ready to be meshed.
- Accordingly, the quality criteria is provided.
- The mesh parameters are set up - maximum and minimum target lengths, tria elements for surface meshing.
- By using Spotmesh option under Mesh generation mdoule, the shell mesh is deployed manually.
- Ortho tria elements are deployed over curved faces while normal tria elements are deployed at flat faces in order capture the features properly.
- Also, if possible, fillets are captured with multiple rows of elements rather than one. This results in a better mesh flow.
- The small holes are captured with 4 nodes in order to allow better mesh flow.
- In order to properly access the inside faces, the commands under Faces Draw tab are used (Or, And, Not, etc)
- Now, the off elements are removed by switching ON the hidden mode. The best way to deal with such off elements is by using the MV Surf command under Grids module.
- Finally a fine surface/shell mesh is achieved.
Volume Mesh :
- Now the VMesh tab is opened.
- In order to fill the volume inside with tetra elements, first the volume need to be defined using the Define button under Volumes module. For this, it needs to be ensured that it is a closed volume (if any open faces are present, ANSA won't consider it as a closed volume and thereby volume mesh cannot be deployed).
- After defining the volume, a proper solid(volume) PID is assigned to it.
- Now, the tetra elements are deployed either by Tetra Rapid or Tetra FEM commands under Unstructured Mesh module, each of which gives a slight different mesh flow. Both these use inbulit ANSA algorithms for deploying the tetra mesh.
- In order to get better results, the mesh is reconstructed by using commands under Improve module.
- The view is switched to hidden mode to deal with the off elements. The most important quality that the model needs to be checked for is Collapse or Tet Collapse. The elements failing under this criteria are to be necessarily removed.
- Finally, the model is checked for any irregiularities on the surface such as peaks or kinks. If found, such geometric issues should be removed by using any suitable tricks. e.g. - Align command under Improve module.
LEARNING OUTCOMES : Got to learn quite a few things -
- How to perform a volumetric mesh over a solid body.
- Intake Manifold is a complex part to model. However, it is advisable to be modelled as a solid rather than by midsurfacing.
- What does an unstructured mesh actually comprise of and how does it look like.
- How to remove any surface dents after deploying the volumetric mesh.
sharable google drive link -
https://drive.google.com/file/d/1CBol2WPHyneiGJHqhNfOhs6ojAejdqck/view?usp=sharing