Wind turbines installed in the open atmosphere experience much more complex and highly-varying flow than their counterparts in wind tunnels or numerical simulations. In particular, aerodynamic stall—which occurs often on stall-regulated wind turbines in such variable flow conditions—can affect both wind turbine blade lifespan and noise generation. A field test site was therefore installed at the outer limits of the city of Waterloo, Ontario to study a small-scale 30 kW stall-regulated wind turbine. Experimental equipment was installed to monitor parameters such as wind speed and direction, electrical power output, blade pitch angle, rotor rotational speed, and wind turbine yaw orientation. Extensive hardware and software was developed and installed to wirelessly collect data from all instrumentation. Tufts and a remote-operated camera were also installed on one of the two blades of the 10 m diameter horizontal-axis turbine. In a variation on the tuft flow visualisation technique, video files were analysed using a novel digital image processing code. The code was developed in MATLAB to calculate the fraction of the blade which was stalled by determining the position and angle of each tuft in every video frame. The algorithm was able to locate on average 85% of the visible tufts and correctly tagged those which were stalled with a bias of only −5% compared to the typical manual method. When the algorithm was applied to 7 h of tuft video at the outboard 40% of the blade, the total average fraction of stalled tufts varied from 5% at 5 m/s to 40% at 21 m/s. This trend was expected for the stall-regulated design since, as the wind speed is increased, the stall progresses from inboard to outboard regions and from trailing edge to leading edge. The 7 h time period represents at least a two order-of-magnitude increase compared with time periods analysed using previous manual methods. This work has demonstrated a digital implementation of tuft flow visualisation which lends statistical validity (through long-time-period averaging) to a common tool for researching wind turbine stall. The speed and ease with which the tuft method can be implemented, combined with the high cost per energy of small-scale wind turbines, suggest that this digital algorithm is a highly beneficial tool for future studies.

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 52-54). Also available on the World Wide Web.

Nesta pesquisa foram realizados levantamentos geofísicos utilizando os métodos eletromagnético indutivo - EMI (equipamento EM38) e GPR - Ground Penetrating Radar, visando localizar redes de interferências, tais como, tubulações metálicas, cabos elétricos e conduítes de plástico instalados nas linhas 6 e 7 do Sítio Controlado de Geofísica Rasa do IAG/USP. Os dados EMI foram afetados pelo drift instrumental devido à variação de temperatura. A sua correção foi efetiva por meio do uso de uma função quadrática, realçando os alvos mais profundos. A aquisição em distância permitiu detectar alvos metálicos no subsolo com boa precisão e a aquisição em tempo permitiu fazer um mapeamento regional de alvos metálicos no subsolo. Os melhores resultados foram obtidos com a aquisição em distância, com os sensores posicionados a 10 cm de altura, devido às anomalias ficarem mais nítidas, onde a influência da condutividade do background foi reduzida. Os perfis GPR 2D obtidos com a antena de 400 MHz permitiram detectar os alvos até 1 m de profundidade e com a antena de 200 MHz foi possível detectar quase todos os alvos metálicos e não-metálicos instalados nas linhas estudas do SCGR. Para o GPR quase-3D, na forma de depth slices, foram importantes para estimar as dimensões dos alvos e melhorar a visualização dos resultados. Os resultados obtidos com os métodos EMI e GPR são complementares, sendo ambos recomendados no mapeamento de interferências no subsolo, tendo aplicações diretas nas áreas de planejamento urbano e infra-estrutura nos grandes centros urbanos. / This research was conducted geophysical surveys using inductive electromagnetic - IEM (EM38 equipment) and GPR - Ground Penetrating Radar methods, to locate network interference, such as metal pipes, electric cables and plastic conduit installed in lines 6 and 7 of test site of the IAG/USP (SCGR). IEM data were affected by instrumental drift due to temperature variation. The correction was effective through the use of a quadratic function, highlighting the deeper targets. The acquisition targets identified in the distance underground metal with good accuracy and acquisition time allowed to make a survey of regional targets metal underground. The best results were obtained with the acquisition in distance with the sensors placed at 10 cm in height, due to deficiencies become more clear, where the influence of the background conductivity was reduced. The 2D GPR profiles obtained with the antenna of 400 MHz to detect the target by 1 m depth and the antenna of 200 MHz was possible to detect almost all metal targets and non-metallic lines installed in the study SCGR. GPR to the quasi-3D in the form of depth slices, were important for estimating the size of the targets and improve the visualization of results. The results obtained with the IEM and GPR methods are complementary, and both are recommended in mapping interference underground, with direct applications in the areas of urban planning and infrastructure in urban centers.

Nesta pesquisa foram realizados levantamentos geofísicos utilizando os métodos eletromagnético indutivo - EMI (equipamento EM38) e GPR - Ground Penetrating Radar, visando localizar redes de interferências, tais como, tubulações metálicas, cabos elétricos e conduítes de plástico instalados nas linhas 6 e 7 do Sítio Controlado de Geofísica Rasa do IAG/USP. Os dados EMI foram afetados pelo drift instrumental devido à variação de temperatura. A sua correção foi efetiva por meio do uso de uma função quadrática, realçando os alvos mais profundos. A aquisição em distância permitiu detectar alvos metálicos no subsolo com boa precisão e a aquisição em tempo permitiu fazer um mapeamento regional de alvos metálicos no subsolo. Os melhores resultados foram obtidos com a aquisição em distância, com os sensores posicionados a 10 cm de altura, devido às anomalias ficarem mais nítidas, onde a influência da condutividade do background foi reduzida. Os perfis GPR 2D obtidos com a antena de 400 MHz permitiram detectar os alvos até 1 m de profundidade e com a antena de 200 MHz foi possível detectar quase todos os alvos metálicos e não-metálicos instalados nas linhas estudas do SCGR. Para o GPR quase-3D, na forma de depth slices, foram importantes para estimar as dimensões dos alvos e melhorar a visualização dos resultados. Os resultados obtidos com os métodos EMI e GPR são complementares, sendo ambos recomendados no mapeamento de interferências no subsolo, tendo aplicações diretas nas áreas de planejamento urbano e infra-estrutura nos grandes centros urbanos. / This research was conducted geophysical surveys using inductive electromagnetic - IEM (EM38 equipment) and GPR - Ground Penetrating Radar methods, to locate network interference, such as metal pipes, electric cables and plastic conduit installed in lines 6 and 7 of test site of the IAG/USP (SCGR). IEM data were affected by instrumental drift due to temperature variation. The correction was effective through the use of a quadratic function, highlighting the deeper targets. The acquisition targets identified in the distance underground metal with good accuracy and acquisition time allowed to make a survey of regional targets metal underground. The best results were obtained with the acquisition in distance with the sensors placed at 10 cm in height, due to deficiencies become more clear, where the influence of the background conductivity was reduced. The 2D GPR profiles obtained with the antenna of 400 MHz to detect the target by 1 m depth and the antenna of 200 MHz was possible to detect almost all metal targets and non-metallic lines installed in the study SCGR. GPR to the quasi-3D in the form of depth slices, were important for estimating the size of the targets and improve the visualization of results. The results obtained with the IEM and GPR methods are complementary, and both are recommended in mapping interference underground, with direct applications in the areas of urban planning and infrastructure in urban centers.

This presentation is a project overview and discussion of Native American participation in preparing documents for the Greater Than Class C Environmental Impact Statement. Tribal representatives were involved in the assessments at the Hanford Site, Nevada Test Site, and Los Alamos National Lab.

Master’s thesis is focused on making the acquaintance of EMC issues and ways of electromagnetic field scanner RS321 utilization for pre-compliance measurements. First part contains analysis of available equipment’s influence on measurement results on the basis of gathered specification. Next part includes an example measurement used as operational manual for scanner and its controlling program. The most important part is correction evaluation for performed EMI measurement of signal generator using its EMC certification protocol and application of gained correction curve on independent EMI measurement of device tested by EMC testing laboratory. Other possibilities of scanner utilization are mentioned in the next chapters. Last part of the thesis contains suitability evaluation of EMC scanner on the basis of findings from performed measurements.