Step 1: Preparing the Geometry

In most cases, you would put the parts comprising the helicopter fuselage into a single part. In this tutorial, separate parts will be retained to support localized mesh density settings.

Build Topology is used to check surface connectivity, and a Material Point will be added to identify the volume mesh region.

Check surface conectivity using Build Topology.
Geometry > Repair Geometry > Build Topology
1. Enable Filter points and Filter curves in the Filter by angle group box.
2. Leave the default values in all other settings.
3. Click Apply.
Most curves turn red indicating a boundary between two surface parts.
Examine the helicopter body parts.
1. Enable Surfaces under Geometry in the display control tree.
  Geometry > Surfaces
2. Zoom in to the helicopter fuselage and examine the geometry.
  Two curves within the tail part are yellow indicating attachment to a single surface. The problem is due to an overlapping sliver surface as shown in Figure 203: Overlapped Sliver Surface.
Figure 203: Overlapped Sliver Surface
Delete the small overlapped surface.
Geometry > Delete Surface
1. Click (Select surface(s)) and click the small triangular surface within the yellow curves.
2. Click the middle mouse button to accept.
3. Click Apply.
Recheck surface connectivity using Build Topology. Use the same settings as before.
Now all curves are red including where the overlapped surface was removed.
Create a Material Point
Geometry > Create Body
1. Enter FLUID for Part.
2. Retain the selection of Centroid of 2 points for Location.
3. Click (Select location(s)) and select two locations such that the midpoint lies within the volume (one on the symmetry surface and other on the far-field surface, see Figure 204: Selection of Points for Creating Material Point). Click the middle-mouse button to accept the selection of the points.
  Figure 204: Selection of Points for Creating Material Point
4. Click Apply so that FLUID appears under Parts in the display control tree.