An intercomparison study between RAMS and CRES-Flow-NS models and evaluation with wind tunnel experimental data: Toward improving atmospheric modeling for wind resource assessment

Abstract

The use of atmospheric models for wind resource assessment in complex terrain is limited by their coarse resolution. Using non-hydrostatic mesoscale models such as RAMS, fine resolution grids and a proper turbulent closure scheme such as the k–ε, it is theoretically possible to describe orographic shear-induced turbulence at microscale level with certain accuracy. In such cases, microscale CFD models modified to represent the interaction of the atmospheric boundary layer with the local orography are proven to show accurate results in idealized cases such as neutral stratification. On the other hand, their limitation in representing real atmospheric interaction between large scale structures and thermal stratification with the flow pattern can introduce significant errors in evaluating wind energy potential. In this work, proper modifications of the RAMS model were performed to simulate 2D wind flow over an isolated hill at high resolution configuration. The results have been compared with the CFD model CRES-Flow-NS and with wind tunnel experimental data. It is found that RAMS is able to reproduce basic flow features with comparable accuracy as the CFD model. This work is part of a major effort to make RAMS a reliable tool for atmospheric flow simulations of various complexity.