Close the Model Editor, then initiate the meshing process by clicking on Mesh in the workflow.
Set Mesh Size & Controls
Under Global Sizing, change the size function method to Proximity. In the Boundary Layer Settings, under Collision avoidance, choose the Layer compression option.
The boundary layer locations will need to be specified. Click Boundary Layer under Mesh Controls in the Objects section of the Mesh template. Use the face selection tool and select the 3 faces on the bottom of the flow volume as shown below.
It can be anticipated that a high mesh resolution will be necessary in the areas surrounding the step. In order to achieve this, use a Body Sizing control. Body Sizing can be found in the Add drop down menu next to Size Controls. Create a Body Sizing by selecting the solid and using an Element size of 0.02m.
Click Generate Mesh under Output or at the top of the screen by the status window for Mesh, AIM should detect that you are ready to generate the mesh and highlight the buttons in blue. Below is an example of the mesh that is generated.