wind energy resource evaluation in a site of central italy ... - WindSim

it is possible to forecast a climatology in a new position B inside the map. It meansthat is possible to “transfer” experimental data from the original position (A) toanother one (B).The procedure that allows to build a “transferred climatology”, making use of theCFD simulations, is explained in the following lines.1) CFD simulations are carried out using boundary conditions somehowdifferent from the actual ones, in order to obtain a better convergence of thesimulations as will be explained in chapter 5.2) As a result of the CFD calculation the speed-up map is found, in a zone wherethe experimental climatology can be placed. The speed-up is defined as theratio between the wind velocity in one point of the map and the windvelocity in a particular reference point.3) This map can be modified (with a linear scaling operation) in the way to havethe speed-up value equal to 1 in the location where the climatology isknown. A new speed-up map is generated.4) Finally, the scalar value of the experimental velocity in the climatologyposition must be multiplied per every value of the CFD speed-up map, inorder to generate a new velocity map, that simulates the “real” velocity inthe numerical domain.5) This procedure is repeated for each sector of the wind rose (12 in the specificcase) and for each velocity bin defined in the frequency table of theclimatology.The use of the “transferred climatologies” is needed when doing a “cross checking”of experimental data, for example when inside the map more than one climatologyis present. In this way, it is possible to use experimental data of one station andforecast CFD wind data in an other position. Then, it is possible a comparisonbetween the data forecasted by simulations and the experimental data, in a secondstation.11