{"title":"湍流估计对机舱激光雷达扫描策略的依赖性","authors":"Wei Fu, A. Sebastiani, A. Peña, J. Mann","doi":"10.5194/wes-8-677-2023","DOIUrl":null,"url":null,"abstract":"Abstract. Through numerical simulations and the analysis of field measurements, we investigate the dependence of the accuracy and uncertainty of turbulence\nestimations on the main features of the nacelle lidars' scanning strategy, i.e., the number of measurement points, the half-cone opening angle, the\nfocus distance and the type of the lidar system. We assume homogeneous turbulence over the lidar scanning area in front of a Vestas V52 wind\nturbine. The Reynolds stresses are computed via a least-squares procedure that uses the radial velocity variances of each lidar beam without the\nneed to reconstruct the wind components. The lidar-retrieved Reynolds stresses are compared with those from a sonic anemometer at turbine hub\nheight. Our findings from the analysis of both simulations and measurements demonstrate that to estimate the six Reynolds stresses accurately, a\nnacelle lidar system with at least six beams is required. Further, one of the beams of this system should have a different opening angle. Adding one\ncentral beam improves the estimations of the velocity components' variances. Assuming the relations of the velocity components' variances as\nsuggested in the IEC standard, all considered lidars can estimate the along-wind variance accurately using the least-squares procedure and the\nDoppler radial velocity spectra. Increasing the opening angle increases the accuracy and reduces the uncertainty on the transverse components, while\nenlarging the measurement distance has opposite effects. All in all, a six-beam continuous-wave lidar measuring at a close distance with a large\nopening angle provides the best estimations of all Reynolds stresses. This work gives insights on designing and utilizing nacelle lidars for inflow\nturbulence characterization.\n","PeriodicalId":46540,"journal":{"name":"Wind Energy Science","volume":" ","pages":""},"PeriodicalIF":3.6000,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Dependence of turbulence estimations on nacelle lidar scanning strategies\",\"authors\":\"Wei Fu, A. Sebastiani, A. Peña, J. Mann\",\"doi\":\"10.5194/wes-8-677-2023\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract. Through numerical simulations and the analysis of field measurements, we investigate the dependence of the accuracy and uncertainty of turbulence\\nestimations on the main features of the nacelle lidars' scanning strategy, i.e., the number of measurement points, the half-cone opening angle, the\\nfocus distance and the type of the lidar system. We assume homogeneous turbulence over the lidar scanning area in front of a Vestas V52 wind\\nturbine. The Reynolds stresses are computed via a least-squares procedure that uses the radial velocity variances of each lidar beam without the\\nneed to reconstruct the wind components. The lidar-retrieved Reynolds stresses are compared with those from a sonic anemometer at turbine hub\\nheight. Our findings from the analysis of both simulations and measurements demonstrate that to estimate the six Reynolds stresses accurately, a\\nnacelle lidar system with at least six beams is required. Further, one of the beams of this system should have a different opening angle. Adding one\\ncentral beam improves the estimations of the velocity components' variances. Assuming the relations of the velocity components' variances as\\nsuggested in the IEC standard, all considered lidars can estimate the along-wind variance accurately using the least-squares procedure and the\\nDoppler radial velocity spectra. Increasing the opening angle increases the accuracy and reduces the uncertainty on the transverse components, while\\nenlarging the measurement distance has opposite effects. All in all, a six-beam continuous-wave lidar measuring at a close distance with a large\\nopening angle provides the best estimations of all Reynolds stresses. This work gives insights on designing and utilizing nacelle lidars for inflow\\nturbulence characterization.\\n\",\"PeriodicalId\":46540,\"journal\":{\"name\":\"Wind Energy Science\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":3.6000,\"publicationDate\":\"2023-05-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Wind Energy Science\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.5194/wes-8-677-2023\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Wind Energy Science","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.5194/wes-8-677-2023","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY","Score":null,"Total":0}
Dependence of turbulence estimations on nacelle lidar scanning strategies
Abstract. Through numerical simulations and the analysis of field measurements, we investigate the dependence of the accuracy and uncertainty of turbulence
estimations on the main features of the nacelle lidars' scanning strategy, i.e., the number of measurement points, the half-cone opening angle, the
focus distance and the type of the lidar system. We assume homogeneous turbulence over the lidar scanning area in front of a Vestas V52 wind
turbine. The Reynolds stresses are computed via a least-squares procedure that uses the radial velocity variances of each lidar beam without the
need to reconstruct the wind components. The lidar-retrieved Reynolds stresses are compared with those from a sonic anemometer at turbine hub
height. Our findings from the analysis of both simulations and measurements demonstrate that to estimate the six Reynolds stresses accurately, a
nacelle lidar system with at least six beams is required. Further, one of the beams of this system should have a different opening angle. Adding one
central beam improves the estimations of the velocity components' variances. Assuming the relations of the velocity components' variances as
suggested in the IEC standard, all considered lidars can estimate the along-wind variance accurately using the least-squares procedure and the
Doppler radial velocity spectra. Increasing the opening angle increases the accuracy and reduces the uncertainty on the transverse components, while
enlarging the measurement distance has opposite effects. All in all, a six-beam continuous-wave lidar measuring at a close distance with a large
opening angle provides the best estimations of all Reynolds stresses. This work gives insights on designing and utilizing nacelle lidars for inflow
turbulence characterization.