Week 5 Challenge : Surface wrap on Automotive Assembly

Aim:

Surface wrapping on Automotive Assemblies of Engine, Transmission & Gearbox Model after merging them.

Objective:

For the given models, check for the geometrical errors and delete surfaces which are unwanted for Surface wrap as shown in the videos. After clearing geometry, Merge all 3 models and perform surface wrap.

Target length for Wrap = 3 mm
Write a detailed report on steps followed to finish this challenge.

Answer:

Surface wrap is the process of meshing where the designer is only interested in the outside surface & the components or surfaces located inside the components will be kept as it is. The external flow simulations which are performed only on outside surfaces without affecting or affected by the inside components are using surface wrapp meshing method.

Received Models:

Engine:

Transmission:

Gearbox:

The received model has many unwanted surfaces & CONS which are not associated with the assembly. These unnecessary things are required to removed from the geometry before proceedings to Meshing.

Topo Cleanup of Engine:

From the model, unwanted parts has been found after hiding all important components & deleted them carefully. This unwanted parts can be rings, balls, small surfaces & other elements which are might be used to create slots, profile curvature or just for reference.

Uncheked ELements, which are deleted using universal delete command.

After hiding some of the components, following unwanted items were found.

As objective of this project is to surface wrap of engine, transmission & gearbox assembly, the triple CONS are not the concern, but the error of single CONS need to be resolved. At following places single CONS errors were found which are resolved by removing duplicate or overlapping surfaces, using TOPO command and by deleting small surfaces or uneanted elements inside that place.

At last to prepare it for CFD meshing, it is required to make the assemblies as closed volume. For this all the holes were closed by creating New surfaces. 

As per objective, the surface wrap will be done by constant element size and because of that parts which are in smaller in size, with very small thickness has been deleted. These parts are belts. Also the pipes, coming of the cylinder & going into the turbocharger were deleted because of very bad & impossible to resolved the surface inssues, were also deleted.

Topo Cleanup of Transmission & Gearbox Assembly:

The assembles were in good condition & they didnt have unwanted items to delete or single CONS to resolve. Following images are showing the condition after converting into close volume. 

Transmission

Gearbox

After performinh topo cleanup, the transmission & gearbox assemblies are merged into the engine assembly using "Merge" option.

After merging them, the complete assembly was checked to make the close volume & at some places new surfaces were also created. 

Before procceding to meshing step, the empty PIDs were removed using "Compress" command. The final list of PIDs is showing in below image.

Surface Wrap:

To create surface wrap, the "Wrap" available in Elements toolbar has been used.

The procedure shown in below image is taken to assigned element size, type, properties to elements and to apply surface wrap to assembly.

Using "Run" option shown in above image is used to apply surface wrap. The following image shows the complete assembly with surface wrap using tria elemens.