Offshore wind simulations using a mesoscale meteorological model WRF (Weather Research and Forecasting) for six months were conducted at a coastal research platform in Ibaraki Prefecture. The simulated offshore wind speeds were validated with results from a dual vertical LiDAR (Light Detection and Ranging) measurement campaign at HORS (Hazaki Oceanographic Research Station). WRF simulations with 500 m and 100 m grid resolutions were run while testing the effects of the observational nudging option on the WRF offshore wind simulations. As a result, the accuracy of the simulated wind speed was found to be slightly improved by just increasing the horizontal resolution from 500 m to 100 m grids. Moreover, a bigger impact was observed when the LiDAR vertical wind profiles above surface layer was nudged to the high-resolution WRF simulation every 10 minutes.

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Our study is for the performance improvement of cross-flow wind turbine by wind collector casing. This casing consists of two flow deflectors and one direction tail blade and can be used without mechanical direction control by the tail blade. Two flow deflectors are used to improve ambient wind environment of the cross-flow wind turbine1). This study is focused on the upscaling of the cross-flow wind turbine with wind collector casing. Therefore, three types of cross-flow wind turbine test models with and without two flow deflectors are investigated by experimental performance tests and numerical 2D flow analyses. One was the base model (D114n12) with 114 mm swept diameter and 12 blades and other two were up-scaled 1.5 times in swept diameter (171 mm). The shape of one up-scaled model (D171n12) is similar to that of D114n12 and another up-scaled model (D171n19) has smaller 19 blades which cross-sectional sizes are same as those of D114n12. The results showed that the up-scaled wind turbine model (D171n19) showed higher performance than other two models and the flow fluctuation around flow deflectors caused by blade passing of D171n19 was smaller than that in case of D171n12 and these were considered to be due to the smaller blades of D171n19 compared to the flow deflectors and the blades of D171n12.

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