Week 5 Challenge : Surface wrap on Automotive Assembly

AIM : To perform surface wrap on automotive assembly in ANSA.

OBJECTIVES :

• To do the Geometry Preparation using TOPO Tools in ANSA
• To perform surface wrapping of the Geometry for the CFD with target length of 3mm.

INTRODUCTION :

Surface wrapping in CFD meshing is used to create a simplified, watertight surface mesh around complex geometries, making it easier to perform simulations. This method is particularly useful for handling intricate or dirty CAD data that would otherwise be difficult to mesh.

The process involves generating a “wrapper” around the geometry, focusing on the external surfaces (Or can be internal surfaces depending on study and input), and ignoring internal details. This results in a clean, closed surface mesh suitable for external flow simulations, such as aerodynamics studies in the automotive and aerospace industries.

Surface wrapping significantly reduces the complexity of the meshing process, and the time required for preprocessing. Surface wrapping, allowing engineers to prepare models for computational fluid dynamics analyses efficiently. By simplifying the geometry, surface wrapping ensures that the mesh accurately represents the physical model while maintaining computational efficiency.

STEPS / PROCEDURE :

1) Loading Geometry

We have given 3 geometries for the Powertrain assembly -

i. Engine

ii. Gearbox

iii. Transmission.

We will go through geometries one by one for the geometry cleanup and then merge the geometries together.

1) Imported Model :-

2) Geometry Cleanup -

Before proceeding to surface wrapping and meshing, we will improve the geometry using tools in TOPO deck.

The first thing to do is to check the single cons and triple cons in the model. These are identified using geometric check tool.

As Shown below we got this much singles cons after performing the geometric check.

We can see from the following image there are lot unwanted surfaces which are not required for the analysis.

We can hide the required surfaces and then delete all the unwanted interfering surfaces. Therefore, we will delete these pipes and close the inlet holes with the surfaces.

Here is the completely closed geometry ready to merge.

Now we will go to the transmission part.

After that Transmission Part looks fine for merge.

Let's move to the Gearbox part

Deleting overlapping surfaces and correcting the surfaces of the part

Before doing surface wrap we should merge all models by following these steps.

Click on File__ > click on Merge __ > Select the model which must merge with the current model present in the workspace __ > Later a pop will show that we should check whether the merge option is selected or not __ > Click OK

For doing the surface wrapping, it is important to close the medium and big holes. we can see the complete assembly After filling all holes.

For surface mesh,

Delete the unwanted PID with the help of compress

Go the mesh tool__ > Classic Mesh __ > Elements__ > Long press on the wrap __ > It’s shows Constant length and Variable length __ > Select the Constant length __ > New pop up appears in that if we Double click on the empty which is present in the status then new tab will gets open [ both tab image as shown below ] __ > Once the tab open if the parameters are untitled the double click on it __ > In that Castellation we had to input the target length, but in this if we choose the large number of target length then most of the surface will not be properly wrap and vice versa for small target length __ > In content the value is seen zero double click on it __ > In that we can see the PID was present in left hand side as shown below in picture, we shall select the whole PID with the help of control + A and after selecting all we should click on the green arrow which is present in the tab itself you can see in the image, once this step has been done all PID has moved from left hand side to right hand side as shown below. Click OK __ > return that tab gets open in which the contents was zero now its shows 101 __> for surface wrap that last tab was open in that RUN button showed just click and it will get started and ends in 15-20 minutes depend on the laptop configuration. __ > Once its completed you can see the ready in status.

Surface Wrap Mesh:-

CONCLUSION :

We have successfully created the mesh wrap for the Engine Assembly.