Surface wraping mesh of transmission system

Objectives:

• To create surface wrap mesh on the given geometrical model.
• To combine different surface wrap mesh models together using different methods.

Procedure:

Generating mesh for any geometry is a two step proccess

• Cleaning of the given topology
• Mesh generation for different types of application.

In this assignment, a general purpose mesh is generated for different elements sizes.

Topological corrections:

The different tools that were used and there functions are given below:

(1) Delete: This function deletes selected Faces. As the Face is deleted the neighboring topological conditions change. If the picked Face to be deleted serves as a parent Face to other linked Faces, then extra confirmation is required for the deletion, and an option to convert all linked Faces to geometry is given.

(2) TOPO>CONS>Release: This function releases CONS which have been automatically joined (pasted) or were joined by the CONS>Paste function.

(3) Fill Hole: This function fills holes on Faces. The holes can be of any shape. Such internal openings can be selected individually, or automatically among the visible ones if they fall below a user specified diameter value. There is the option to create automatically 3D Curves, Points or Connection Points of the removed holes, in order to mark their shape and position for reference.

Mesh setup:

Different tools that were used to setup mesh were given below:

(1) Wrap [Constant Length]: Constant Length Wrap is a very fast algorithm that can create a watertight triangular surface mesh of uniform size from an assembly of unconnected and intersecting components. It can be used for various analyses like CFD, NVH and more.

(2) Fill [Manual]: This function serves to fill openings on the shell mesh. The gap will be closed with FE that will be created between two sequences of edges or perimeters. By selecting at least one more edges line or perimeter which connects the two opposite ones the resulted mesh will be connected also to those edges.

(3) MESH>Elements>New: This function defines new Elements by selecting nodes, edges, shell Elements or facets.

(4) MESH>Grids>Paste: This function is used to paste nodes. The parameters to handle the pasting procedure are defined in the PASTE window that appears as the function is activated. Two selection modes are available (Nodes and Node Sets). The user may define if the nodes will be pasted in pairs or to the last selected one. Moreover the final position that a pair of pasted nodes will be placed, can be defined parametrically (0 -1). Note that the paste procedure affects the element\'s nodes and not the nodes themselves.

(5) MESH>Grids>MV Surf: This function moves a selected mesh node on the Macro Area\'s surface, or a perimeter node along the perimeter segment on which it lies. Also it moves a node belonging to FE-model mesh on the surface which is defined by the adjacent shell elements.

(6) OPENFOAM>NODE>RELEASE: This function releases a number of selected grid points that belong to more than one FE-MODEL entities.

Initial geometry:

The figure that are given above are the initial geometry for which the wrap mesh is to be generated. The clean up process is done by the following steps:

- The wrap mesh is defined above, therefore the elements that are afloat have to be deleted to reduce uneccessary warping.

- All the holes in the above geometry have to be filled. The fill hole algorithm only fill those holes which are single cons. Therefore, we must release all the double CONs to convert it into single CONs by using split option. Then fill holes tool can be used to create surfaces at all the holes present at the geometry.

Meshed geometry:

The Mesh was not created in the conventional way but a surface wrap mesh was created. The surface wrap mesh is like covering the geometry with a vaccum bag and then sucking the air out of it. The surface wrap gives approximate mesh for the geometry.

The surface wrap mesh for the above models is given below:

These three models have to be joind together so that it can be joined together, to make them a single component. The merging process of these three components is done by:

• First, the faces have to be deleted from each face. The area of the face that has to be deleted should retain the shape of the orignal element.
• To trace out area that comprises the shape of gear box \"Release\" tool is used which under deck section.
• Then the face area is deleted for both transmission and gear box.

• Then the deleted faces can be joined by performing operations like paste, fill, new elements tools

The joined faces of gearbox and trannsmission is given below:

The second method to form connections between the two geometry is:

• The connection are formed using Paste, fill, new elements tools directly without deleting the faces. In this process the triple bounds are formed and thus a seperate PID region is formed.
• Then this PID region can be removed using delete option and thus making perfect bounds.

The figure given below is the completed surface warped mesh with all three components joined together:

Result:

The surface wrap was created for all three components and three components were merged together.