I thought Discovery Live is capable of working with faceted geometries directly? Below is a video for an earlier version of Discovery Live where the simulation was done on the faceted geometry. However the interface seems to have changed and the options are not shown when I double click on a boundary when I am in Design/Facets tab. However when I select Fluid Flow from Simulation tab, I no longer can select the faceted face.
My geometry is extremely complex with upwards of few hundred thousand faces, so if possible I would like to avoid converting to CAD. This is also the reason why I use fault tolerant workflow in FLUENT as it helps me extract the fluid domain from STL files using wrapper.