As I mentioned earlier, we find that the First Layer thickness option is the best place to start, especially when you are trying to achieve a particular y+ value as this value can be parametrised in ANSYS Workbench so that any changes to the First Layer Thickness parameter will be proportional to the y+ values that you expect in your solution. The first layer thickness that you choose should be used to obtain the correct y+ value for the turbulence model and flow behaviour that you are dealing with, which we will discuss in a future post.