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AIM will prompt you to fix the boundary layer before generating the mesh. Click on Boundary Layer under Mesh Controls. Select the faces of the volume in contact with the Ahmed body, as shown below. The simplest way to do this is to drag a box around the Ahmed body, from the upper left to the lower right. AIM will select all faces that are completely enclosed.
Generate Mesh
Return to the Mesh panel, then click Generate Mesh under Output or at the top of the screen by the status window for Mesh. AIM will detect that you are ready to generate the mesh and highlight the buttons in blue.
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