Previous work has shown that the Discrete Element Roughness Method (DERM) can accurately model surface roughness without explicitly resolving the roughness. In this work, the underlying models of the roughness are evaluated. DERM theory relies on correlation of momentum and energy loss, which, create effort terms that couple to the governing equations. These effort terms can then be implemented into Computational Fluid Dynamics (CFD) simulations, which are used to model the heat transfer of surface roughness created from surface roughness. In this effort, these underlying models are directly evaluated using resolved roughness elements in a CFD simulation. The results are then used to improve the underlying correlations.