Surface Repair Star-ccm+

Objective- 1. Perform surface repair for a Glider plane model in Star ccm+.

2. Scale the geometry of Ahmed body by 3 times and rotate so that the angle of attack will be 35 degrees.

Types of errors:

1. Pierced face -A Pierced face is a face that is intersected by one or more edges of another surface.This type of errors are shown in red color in starccm+.

2.Face quality -Face quality is the similarity between a face with an ideal face which is an equilateral triangle.This is calculated as the ratio of radius of in-circle to circum-circle (of the triangle) multiplied by 2.Face quality ranges from 0 to 1 ,0 resembling a line and 1 as equilateral triangle.These errors are denoted in yellow color.

3. Face proximity-It is the measure of how close two faces are with each other.It also ranges from 0 - 1 and 0 indicating poor face proximity.These errors are denoted in orange color in surface repair.

4. Free edges - If a edge is joined to only one face then this this type of error is called as free edge.This is shown in green color in surface repair.Can be fixed by patching them.

5. Non-manifold edges - If an edge is shared by three or more faces then it causes non maifold edge.Denoted in blue color.This can be fixed by deleting extra faces.

6. Non-manifold vertices -If there is only one concact between two faces in form of a vertex/point then it is said to be non-manifold edge.Denoted in blue color.

Steps for repair of a Glider model:

1. Launching the surface Repair Tool:

The surface repair tool can be launched by right clicking the body and selecting surface repair.Once the window for surface repair is launched we can dignose the errors by clicking execute button.

So the total number of errors are below for the given glider model is shown in the below figure.The type of errors are classified and denoted in different colors.

2. Fixing the Free edges & non-manifold vertices:

The free edges in the wing region can be fixed by filling the area.This can be done by selecting vertices and creating faces from vertices as shown in the below figure.This step also can be done by selecting edges and filling them.Once the open edges get fixed,automatically the non-manifold vertices also gets fixed.

3. Fixing the Non-manifold edges:

The non-manifold edges are found in the tail end of the glider.This error has occured due to duplicate faces.

The non-maifold edges in this case can be fixed by deleting the duplicate faces that is present as shown in the figure below.

Once the duplicate faces are deleted we can delete the extra faces associated with it a shown.

Once the above steps are done automatically the pirced faces gets fixed.

Final cleaned up model:

From the below figure we can see that the the errors have been reduced to zero after performing the above operations.

The face proximity and face quality errors can be fixed while using surface remesher and surface wrapping.

Scaling the geometry of Ahmed body by 3 times and rotate so that the angle of attack will be 35 degrees.

Model before scaling:

Model after scaling:

1. The ahmed body is scaled to three times using transform option and its transformed to 3 times the original model.

2. The ahmed body is also rotated so that the angle of attack will be 35 degrees.This is done using the transform option and clicking on rotate.

Surface repair file.

https://drive.google.com/file/d/1GMDXzggayQd21f7AAbOt_Z3CxGOmbwZq/view?usp=sharing

Ahmed body file.

https://drive.google.com/file/d/133dNm0oBE2B5v5zvuCfo2WSJJAQBDGOt/view?usp=sharing