Project 1 : CFD Meshing for Tesla Cyber Truck

AIM: -

To perform volumetric (CFD Meshing) on the given Tesla truck

->ANSA- (Automatic net generation for structural analysis) is a computer-aided engineering tool for Finite Element Analysis and CFD Analysis widely used in the automotive industry. It is developed by BETA CAE Systems [Source: - Wikipedia]

->It is used for pre-processing task and it includes proper clean-up like a geometric clean up.

-> 2D & 3D it is very widely used in CA applications.

->ANSA maintains the association between CAD geometry and the FE mesh.

Objective: -

For the given model, check and solve all geometrical errors and assign appropriate PIDs. Perform meshing with the given Target length and element Quality criteria.

Target lengths for the different parts of a model are as follow:

1. Body - 3 mm
2. Rims and Tyres - 2 mm
3. Window - 2 mm

Element type = Tria

Procedure: -

Step 1: - Importing the CAD Model

Go to the file - > open the file - > Search the location, where the CAD model is present- >Supposed another model is open in workspace then it will be discarded or saved - >Certain path where we had download or save the model, It can be identified by ‘’Turbocharger ANSA’’ - >Select it & click on enter.

Step 2: - Geometry clean-up

As we can see in above figure that the whole model surface is not in uniform/accurate. For that we can use FIT tool that is present in the TOPO_ > AUXILIARIES _ > FINE but this is a long method we will be using MESH _ > PERIMETERS_ > LENGTH _ > PERIMETERS & MACROS tool with the length 2mm. before doing this step we will be using TOPO clean up so that the some of the single cons gets converted in to double cons.

Now we can see single cons by using wire mode [ control+shift] & also triple cons, since once we solve both single cons as well as triple cons then we can go for a meshing mode.

__ > we will be using the tool to create a new faces where required after doing this will be checking the geometry errors

Step 3: - Assign PID

Steps for PID assign…. Properties _ > Click _ > New pop-up box, It will shows the Pshell contain or PID

How to create a new PID?

To create a new PID_ > Right click _ > New _ > Pshell _ > new box will come up _ > Name (e.g.:- Body) _ > OK _> Properties new PID present _ > we can also change the colour by clicking twice on this □

To assign PID _ > Click on the PID, which must apply on our model _ > Right click _ > Apply _ > Go to the model _ > Take the cursor to the Cross edge / face and click centre button.

How to delete extra PID _ > Select the PID _ > Go to the compress tool which is present in upper row, as shown below.

Step 4: - Meshing

Using Quality Criteria tool for adding or removing Criteria we are going to follow some step i.e. Click on Quality criteria __ > Tab open __ > In section SHELLS in that if we would like to add or remove, we will be using edit criteria option __ > for Changing the criteria values we need to select or tick the box

In Quality criteria if we are choosing 2D elements we will be going for Shells similarly for 3D elements we will be going for solid.

Since in this model we will be using quality criteria, if the assume length of minimum value observed is less then we will be using the cut tool to increase the distance between the nodes or cons.

The below picture represents the PID of body, in these the length observed is less than the minimum length so used he cut tool

Step 5: - Wind Tunnel

In wind tunnel first we have to measure the length of the car with the help of measure tool as shown below, the car total length approximately is 5950mm

Since X=5950 mm Car length

Let’s create a points which is present in TOPO __ > POINTS __ > Relative__ > Click the centre of the car from the bottom side as shown below in picture & later we had put the values in Y-axis as -75mm because the “ – “ sign indicate downwards axis as we are aware about quadrants.

Since WKT front side of the wind tunnel is 4x + the distance of the half car and the total values occurs is 26775mm and uses the same method to create the points as shown below,

Similarly, we will be doing for back side or rear side of wind tunnel i.e., 6x + the distance of the half car and the total values occurs is 38675mm and uses the same method to create the points as shown below,

For top surface the distance is 3x for the wind tunnel randomly insert the hot points at the top surface to take a reference of +3x

For the side wind tunnel surface, we had to use the top view of the model use to 2x as a distance from the front point 4x and the back point value i.e., 6x since the value will be

Now will be connecting those points with the help of curve which is present in TOPO__ > Curve __ > Create

Now we had to create the new faces and to assign the PID

After assigning the PID we are deleting that upper point because we will be using the offset tool which is present in TOPO __ > Faces __ > Offset __ > Value for upper surface, since we are inserting the value in negative since the arrow direction is in negative quadrant

Once the above surface has appeared we going to delete the curve and the points which are created for the references & going to crated all the surfaces and assign the PID

Now we are moving towards the meshing since for top surface target length 100 mm & Base surface target length 20 mm and for front and back surface we will be using spacing tool which is present in perimeters, since the values we are taking is Dstart is 20 mm because it starting from base surface and gradually increases the Dlimit is 100 mm ending at top surface, since in this we will not be considering the quality criteria and mesh perimeter because it gradually increasing

Now Volumetric mesh

Before using V-mesh, we had to mesh the whole model.

V-mesh _ > Volume _ > Defence _ > Ask whole DB[data base] or visible , Go for whole DB _ > Click OK _ > Volume list appears or volume list can be select under the volumes