Description Of Downscaling Methodologies

Roberto Aurelio Chávez Arroyo, Javier Sanz Rodrigo, Andreas Bechmann, Matias Avila, Herbert Owen, Chi-Yao Chang, Arnaud Candaele
2016 Zenodo  
This report describes the first tasks towards the downscaling methodologies that will be used to link mesoscale outputs from the New European Wind Atlas with microscale models in connection to wind farm design tools. This initial report provides a review of existing downscaling methodologies applied in the context of wind energy applications. This is used to frame the development of the NEWA model-chain which will allow microscale models to be used in connection to input data derived from
more » ... derived from mesoscale models. The mesoscale to microscale methodology will provide means to relate the long-term wind climatology, characterized by a mesoscale model, with the design conditions at site level where wind farm design takes place. This report deals with microscale models, typically implemented on computational fluid dynamic (CFD) solvers. A list of the participating models in NEWA is provided in the Annex. The initial challenge is to make theses codes intercomparable so we can extract meaningful conclusions when we evaluate simulations in connection with validation cases. Before comparing simulations and observational data, we need to assess the numerical error due to the sensitivity of the result to the model set-up. This is particularly important in complex terrain where grid dependencies can be significant. The objective of the initial effort of the NEWA microscale team has been focused on using different methods of assessing grid dependencies. This has been done with different microscale models applied to the three complex terrain test cases where dedicated field experiments are planned: Kassel (forested hill), Perdigao (double-hill) and Alaiz (hill and mountain range). In order to make the results more comparable in terms of numerical errors, the reference physical model adopted in the study has been based on neutral, steady-state, surface-layer conditions. This is a Reynolds-independent model that removes the dependency of the results with the wind speed. The results show significant variability of [...]
doi:10.5281/zenodo.1194733 fatcat:s2uhohpe5reurerjneav6gvgq4