In this work is proposed the design of a dynamometer based on Foucault's Current Break for the evaluation of torque and power provided by a Savonius wind turbine model in a wind tunnel. The applied measurement system is of the open source type using the Arduino platform. For the reaction force metering a load cell with converter and amplifier H711 was used as well as a photoelectric sensor with resolution of one pulse per turn for the rotation measurement. Equations available in the literature were used to estimate the wind turbine performance parameters for the dynamometer sizing. The wire applied for magnetic flux generation in the coils is AWG24, to support an electrical current rating of 0.5 A and a voltage of 1.0 V. The coils size are 3.1 cm of diameter and 3.0 cm of length. Two coils were applied in order to satisfy the wind turbine demand. As a result, the dimensional characteristics of an eddy current brake able to measure a power of up to 0.5 W, generated by a Savonius wind turbine, were obtained, with uncertainty of measurement about 0.01 W, being adequate for the analyzed turbine.

Neste trabalho é proposto o dimensionamento de um freio dinamométrico baseado nas correntes parasitas de Foucault para medição de torque e potência disponibilizada por um modelo de uma turbina do tipo Savonius em um túnel de vento. O sistema de medição empregado é do tipo open source utilizando a plataforma Arduino. Para a medição da força de reação foi utilizada uma célula de carga com conversor e amplificador H711 e para a medição de rotação um sensor fotoelétrico com resolução de um pulso por volta. Para o dimensionamento do dinamômetro utilizou-se os parâmetros de desempenho da turbina calculados a partir de equações disponíveis na literatura. O fio empregado nas bobinas para gerar o fluxo magnético é o AWG24, para suportar uma corrente elétrica de 0,5 A e tensão elétrica de 1,0 V. As dimensões das bobinas foram de 3,1 cm de diâmetro e 3,0 cm de comprimento. Para atender a demanda da turbina duas bobinas foram empregadas. Como resultado, foram obtidas as características dimensionais de um freio de Foucault capaz de medir uma potência de até 0,5 W gerada por uma turbina Savonius, com incerteza de medição de 0,01 W, sendo adequada para a turbina analisada.

The paper presents the results of a study with temperature measurements using low cost sensors connected to an Arduino microcontroller. To perform the study, three sensors widely used for monitoring environmental conditions with Arduino. The selected sensors were the LM35DZ (analog sensor) and DHT11 and DHT22 (digital sensors). The LM35DZ sensor is a sensor known to be an analog sensor that has linear temperature response with voltage. The DHT11 sensor measures temperature and humidity simultaneously.  To measure temperature the DHT11 sensor uses a temperature-sensitive resistor and has a measurement range from 0 to 50 °C, with an uncertainty ± 2% ° C. The DHT22 has a measurement range  -40 to 80 ° C and an uncertainty ± 1% ° C.  Simultaneous temperature measurements with the three sensors showed good performance in indoor situations, showing the maximum and minimum temperatures of a daily temperature cycle.

The WRF (Weather Research and Forecast) is a numerical modeling applied to the atmosphere. This model was developed for weather forecasting and investigation of atmospheric mesoscale phenomena. The WRF is a public domain and free distribution, with different applications ranging from the field of meteorology to engineering, and can be applied in situations of idealized atmosphere or real atmosphere. Presently, the wind field simulated by this model has been used as real data. Thus, the WRF model started to be employed in wind analysis for wind power generation. In this work, the wind field was simulated using the WRF model, in Cachoeira do Sul, Rio Grande do Sul, Brazil.