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You searched for subject:(Ultrasonic anemometers). Showing records 1 – 2 of 2 total matches.

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1. Van Overbeke, Philippe. Development of a reference method for ventilation rate measurements in a naturally ventilated test facility.

Degree: 2015, Ghent University

Gases produced in animal houses, such as NH3 and CO2, are not only harmful to the animals and farmers, but can also have negative effects on the environment. An optimum has to be found between maintaining a suitable indoor climate and preventing excessive emissions. For indoor climate control and especially emission measurements a reliable estimate of the airflow rate is essential. However, for naturally ventilated animal houses, no generally accepted reference technique exists to measure the airflow rate. Most existing techniques fail to account for the heterogeneous airflow patterns caused by the constantly changing external conditions of wind speed and direction. A new measuring method was developed through a stepwise approach starting from steady state measurements in wind tunnels up to measurements in a real size naturally ventilated test facility. This method, based on the automated traverse movement of a 3D ultrasonic anemometer across a rectangular vent, delivered detailed velocity profiles from which the airflow rate could be calculated. It was proven that the method accounts for both the temporal and spatial variability of the velocity profiles which are characteristic of naturally ventilated openings. The relative measurement error between the total building inflow and outflow rates remained within the range of ±20%. Due to the extensiveness of the experiments under a large range of wind incidence angles and speeds, a unique reference testing platform was created. The in depth knowledge of the velocity profiles and the associated in- and outflow rates through each vent, create possibilities for the development, the calibration and the validation of new and existing airflow rate measurement techniques for natural ventilation. Advisors/Committee Members: Pieters, Jan, Demeyer, Peter.

Subjects/Keywords: Agriculture and Food Sciences; Ultrasonic anemometers; Animal houses; Natural ventilation; Emissions; Ventilation rate

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Van Overbeke, P. (2015). Development of a reference method for ventilation rate measurements in a naturally ventilated test facility. (Thesis). Ghent University. Retrieved from http://hdl.handle.net/1854/LU-6995644

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Van Overbeke, Philippe. “Development of a reference method for ventilation rate measurements in a naturally ventilated test facility.” 2015. Thesis, Ghent University. Accessed March 28, 2020. http://hdl.handle.net/1854/LU-6995644.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Van Overbeke, Philippe. “Development of a reference method for ventilation rate measurements in a naturally ventilated test facility.” 2015. Web. 28 Mar 2020.

Vancouver:

Van Overbeke P. Development of a reference method for ventilation rate measurements in a naturally ventilated test facility. [Internet] [Thesis]. Ghent University; 2015. [cited 2020 Mar 28]. Available from: http://hdl.handle.net/1854/LU-6995644.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Van Overbeke P. Development of a reference method for ventilation rate measurements in a naturally ventilated test facility. [Thesis]. Ghent University; 2015. Available from: http://hdl.handle.net/1854/LU-6995644

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Universidade Federal do Maranhão

2. Will Ribamar Mendes Almeida. Anemômetro Baseado no Método de Tempo de Trânsito: Estudo comparativo de arquiteturas, avaliação de incertezas e implementação.

Degree: 2004, Universidade Federal do Maranhão

Anemometers are instruments, simply, for measuring the velocity of fluids and, in some cases, its direction. Particularly, the measurement of the air velocity extends to applications like: windmills, wind tunnels, electricity generation from Aeolian energy and meteorology. Among the most used methods for the wind velocity determination, the method based on the transit time of ultrasonic waves is stressed for being more suitable to the measurement of the velocity of gases, and which is based on the time required for an ultrasonic wave emitted from a transmitter to reach a receptor. Among the techniques for implementing the transit time the Difference of Time (DT) and Difference of Phase (DP) are emphasized, and both are addressed ins this work. A comparative study, with experimental verification, between the two techniques (DT and DP) is presented in this work, using techniques for compensating the effects of temperature variation on the sound velocity. It was taken into consideration the implementation of the measurement circuits and the propagation of uncertainties with respect to the variables that interfere in the measurement process. From the analyses carried out, the most suitable method for measuring the wind velocity was chosen, and a prototype was developed based on this method. The most suitable method is the Difference of Phase, because the observed uncertainty, in both simulations and experiments, was much smaller than for the DT method.

Anemômetros são instrumentos que, de maneira simplificada, têm a finalidade de medir velocidade de fluidos e, em alguns casos, a sua direção. Em particular a medição da velocidade do ar estende-se a aplicações como: moinhos de vento, túneis de vento, geração de energia elétrica a partir da energia eólica e meteorologia. Dentre os métodos mais comuns de determinação da velocidade de vento destacam-se os que se baseiam no Tempo de Trânsito de ondas ultra-sônicas, por serem mais adequadas para medição de velocidade de gases, e que se baseiam no tempo levado para uma onda ultra-sônica emitida por um transmissor atingir um receptor. Dentre as técnicas usadas para implementar o método do Tempo de Trânsito destacamse a Diferença de Tempo (DT) e a Diferença de Fase (DF), ambas abordadas neste trabalho.. Um estudo comparativo, com verificação experimental, entre as duas técnicas (DT e DF) é apresentado neste trabalho, usando técnicas para compensar os efeitos da variação da temperatura na velocidade do som. Foi levado em consideração na comparação à implementação dos circuitos de medição e a propagação de incertezas com relação as variáveis que interferem no processo de medição. A partir das análises realizadas escolheu-se o método mais apropriado para estimação da velocidade do vento, tendo sido desenvolvido um protótipo baseado nesse método. O método mais apropriado foi o da diferença de fase, pois foi observado, tanto por simulação quanto por experimentação, que a incerteza na estimação da velocidade do vento foi bem maior para o método DT.

Advisors/Committee Members: Sebastian Yuri Cavalcanti Catunda.

Subjects/Keywords: Anemometers; Ultrasonic transducers; Medidores de fluidos; Fluid measurers; Transdutores ultra-sônicos; Anemômetros; MODELOS ANALITICOS E DE SIMULACAO

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Almeida, W. R. M. (2004). Anemômetro Baseado no Método de Tempo de Trânsito: Estudo comparativo de arquiteturas, avaliação de incertezas e implementação. (Thesis). Universidade Federal do Maranhão. Retrieved from http://www.tedebc.ufma.br//tde_busca/arquivo.php?codArquivo=235

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Almeida, Will Ribamar Mendes. “Anemômetro Baseado no Método de Tempo de Trânsito: Estudo comparativo de arquiteturas, avaliação de incertezas e implementação.” 2004. Thesis, Universidade Federal do Maranhão. Accessed March 28, 2020. http://www.tedebc.ufma.br//tde_busca/arquivo.php?codArquivo=235.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Almeida, Will Ribamar Mendes. “Anemômetro Baseado no Método de Tempo de Trânsito: Estudo comparativo de arquiteturas, avaliação de incertezas e implementação.” 2004. Web. 28 Mar 2020.

Vancouver:

Almeida WRM. Anemômetro Baseado no Método de Tempo de Trânsito: Estudo comparativo de arquiteturas, avaliação de incertezas e implementação. [Internet] [Thesis]. Universidade Federal do Maranhão; 2004. [cited 2020 Mar 28]. Available from: http://www.tedebc.ufma.br//tde_busca/arquivo.php?codArquivo=235.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Almeida WRM. Anemômetro Baseado no Método de Tempo de Trânsito: Estudo comparativo de arquiteturas, avaliação de incertezas e implementação. [Thesis]. Universidade Federal do Maranhão; 2004. Available from: http://www.tedebc.ufma.br//tde_busca/arquivo.php?codArquivo=235

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.