published_or_final_version / Mechanical Engineering / Master / Master of Philosophy

The research focusses on computational analysis of vortex generation behind A-Pillar of simplified model derived from Jaguar XF that excludes air from the underside of vehicle. This vortex formation contributes in generating wall pressure fluctuations especially at speeds higher than 100km/hr. It is a collaborative work between Cranfield University and Jaguar Land Rover. Three dimensional pressure based incompressible flow using Large Eddy Simulation turbulence model is selected for computational analysis in FLUENT v14. This used high parallel computing systems available in Cranfield University. In the initial phase, three grid resolutions (coarse, medium and fine) were prepared in ICEM CFD with fine case consisting of 10 million cells. Qualitative analysis includes extraction of slices, 3-D and surface streamlines and pressure and velocity contours for capturing the unsteadiness due to the vortex formation over the front side glass surface. The iso-surface of Q captures the unsteadiness at the A-Pillar wake and side mirror wake over front side glass surface. It also reveals that the range of length scales captured were limited even at the finest grid resolution. Quantitative analysis compares the mean pressure (Cp) data with JLR results. Probes were located at 51 locations over the front side glass window that showed a good comparison; specifically for the fine grid; with maximum variation incurred at probes located in separation areas. For predicting the wall pressure fluctuations, a total of ten probes were located over the front side glass window surface. The surface pressure (static) data was recorded for 1 sec of flow-time and later imported in MATLAB for post-processing. The results obtained in 1/3rd octave band showed that the large scales were too energetic and small scales are not captured. However, comparing sound pressure levels with the Aero-acoustic Wind Tunnel (AWT); provided by JLR; it is concluded that either the grid is too coarse to resolve higher frequencies or the numerical modelling used is too dissipative to benefits the use of LES.

Thesis (M.S. in Engineering Acoustics)--Naval Postgraduate School, December 1990. / Thesis Advisor(s): Atchley, Anthony A. ; Hofler, Thomas J. "December 1990." Description based on title screen as viewed on March 31, 2010. DTIC Descriptor(s): Heat Transfer, Coupling (Interaction), Peak Values, Ratios, Temperature, Thermodynamics, Edges, Isolation, Sensitivity, Regions, Short Range (Time), Profiles, Plates, Internal, Acoustic Arrays, Pressure, Drives, Leading Edges, Mean, Amplitude, Sound Pressure, Stacking, Thermopiles. DTIC Identifier(s): Heat Pumps, Energy Conversion, Energy Storage, Heat Transfer, Thermoacoustic Couples, Theses Author(s) subject terms: Acoustics, Thermoacoustics, Thermoacoustic Heat Transport. Includes bibliographical references (p. 34). Also available in print.

Thesis (M. Phil.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 187-190).

Thesis (Ph. D.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xviii, 193 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 191-193).

Sound pressure level (SPL) is known to cause stress in cattle but is often overlooked as a potential source of fear for cattle when designing handling equipment. Current literature does not offer guidelines for the design of equipment with regard to SPL. It is, however, recommended that handling equipment should be designed to minimize the SPL during handling. The purpose of this experiment was to measure stress levels in a group of cattle which were subjected to a series of varying sounds in order to determine a design threshold limit for handling equipment. Treatments included two frequencies, 1 kHz and 8 kHz, and three intensities, 40, 80, and 120dB. These treatments were assigned to the cattle using a completely randomized two by three factorial design replicated three times for a total of 18 animals being tested. A computer generated noise at each level was played back to the animals once a week for 6 weeks. Stress levels were measured using both physiological (heart rate and eye temperature) and physical (sudden movement) measures. Experiments yielded mixed results and did not prove that any of the sound pressure levels tested had any great effect on the stress level of the cattle.

Submitted by Victor Manieri Schutzer null (victor_schutzer@hotmail.com) on 2018-04-05T01:19:20Z No. of bitstreams: 1 Dissertação completa - victor manieri schutzer.pdf: 2057859 bytes, checksum: 965ab65ab6bb0942e2639d8fdfbafe05 (MD5) / Approved for entry into archive by Lucilene Cordeiro da Silva Messias null (lubiblio@bauru.unesp.br) on 2018-04-05T12:41:58Z (GMT) No. of bitstreams: 1 schutzer_vm_me_bauru.pdf: 2057859 bytes, checksum: 965ab65ab6bb0942e2639d8fdfbafe05 (MD5) / Made available in DSpace on 2018-04-05T12:41:58Z (GMT). No. of bitstreams: 1 schutzer_vm_me_bauru.pdf: 2057859 bytes, checksum: 965ab65ab6bb0942e2639d8fdfbafe05 (MD5) Previous issue date: 2018-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A crescente mecanização na agricultura mundial foi acompanhada do aumento do número de acidentes e fez com que elevasse a preocupação com a saúde de seus operadores, já que tais trabalhadores estão expostos aos riscos que esse tipo de atividade proporciona. Alguns dos graves problemas que são gerados pelos equipamentos agrícolas é a alta vibração e ruído a que os operadores ficam expostos na sua jornada de trabalho. A vibração que atinge os trabalhadores pode ser considerada como um distúrbio, já que é responsável por grandes prejuízos à saúde do ser humano, estando diretamente relacionada com a fadiga do trabalhador. O ruído, considerado como um som indesejável, é outro problema gerado por máquinas motoras e responsável por lesão no aparelho auditivo e, até mesmo, por estresse psicofisiológico. Para o presente trabalho, analisou-se os riscos físicos que a vibração e o ruído causam em operadores de roçadoras motorizadas. Foram feitas análises de situações reais que os usuários deste tipo de máquina enfrentam no seu dia a dia de trabalho, para que se possa tirar conclusões da possibilidade de efeitos danosos. Para a pesquisa utilizou-se um acelerômetro de três eixos - HVM 100, marca Larson Davis, para mensurar a vibração captada pela mão do operador e um medidor de pressão sonora, marca Instrutherm, modelo DEC-460 para mensurar o ruído causado pela roçadora. Para a análise da vibração captada pela mão dos operadores foi utilizada a norma internacional ISO 5349 (2001) – Vibração Mecânica – Medição, Avaliação da Exposição Humana da Vibração Transmitida à Mão e Diretiva Europeia 2002/44/EC que estabelece os limites de exposição à vibração. As análises do ruído foram feitas a partir da Norma Regulamentadora – NR-15 – Atividades e Operações Insalubres. Os resultados de vibração e ruído apresentados em alguns testes ficaram acima do que estabelece a norma para que não haja prejuízo à saúde dos operadores deste tipo de equipamento durante uma exposição equivalente a uma jornada de trabalho de 8 horas. Além disso, mostra a importância do estudo, escolha e, principalmente, da correta utilização de EPI (Equipamento de Proteção Individual) para que minimize a vibração e o ruído que chegam ao organismo humano. É importante, ainda, a manutenção periódica dos equipamentos mecânicos para que os mesmos funcionem corretamente, evitando quebras das máquinas e danos aos operadores de tais equipamentos. / The increasing mechanization in world agriculture was accompanied by an increase in the number of accidents has caused concern about the health of its operators, as these workers are exposed to risks that this type of activity provides. Some of the serious problems that are generated by agricultural equipment are the high vibration and noise to which operators are exposed in their work. The vibration that affects the workers can be considered as a disorder, since it is responsible for major damages to the health of human beings, being directly related to worker fatigue. Noise, regarded as an unwanted sound, is another problem caused by motorized machines and responsible to hearing damage and even to psychophysiological stress. For this study, a physical risks analysis was made. So it is possible to determine the damage that vibration and noise can cause in motorized brushcutter’s operators. Real situations of the daily work that these users go through were analyzed, so that conclusions can be made of the possibility of harmful effects. For the research, an accelerometer of three axes - HVM 100, Larson Davis brand, was used to measure the vibration captured by the hand of the operator and a sound pressure meter, Instrutherm brand model DEC-460, was used to measure the noise caused by brushcutters. For the vibration analysis captured by the hand of the operators, the international standard ISO 5349 (2001) - Mechanical Vibration - Measurement and Evaluation of Human Exposure to Hand-Transmitted Vibration and the European Directive 2002/44/EC establishing the exposure limits for vibrations were used. Noise analysis was made based on the Regulatory Standard - NR-15 - Unhealthy Activities and Operations. The noise and vibration results in some tests were above the standard so that there is no damage to the health of the operators of such equipment during an exposure equivalent to an 8 hours working day. This also shows the importance of the study, choice and especially the proper use of PPE (Personal Protective Equipment) to minimize vibration and noise coming to the human body. The regular maintenance of mechanical equipment is also important so that they function properly, avoiding machinery breakages and damage to operators of such equipment.

Submitted by LAÍS MONIQUE MENDES SALLES (laismoniquems@gmail.com) on 2018-05-29T14:47:15Z No. of bitstreams: 1 Dissertação_Laís_Salles.pdf: 3116151 bytes, checksum: a926dc1c26c90b48c73a7ebf5d913a93 (MD5) / Approved for entry into archive by Cristina Alexandra de Godoy null (cristina@adm.feis.unesp.br) on 2018-06-04T11:58:55Z (GMT) No. of bitstreams: 1 salles_lmm_me_ilha.pdf: 3116151 bytes, checksum: a926dc1c26c90b48c73a7ebf5d913a93 (MD5) / Made available in DSpace on 2018-06-04T11:58:55Z (GMT). No. of bitstreams: 1 salles_lmm_me_ilha.pdf: 3116151 bytes, checksum: a926dc1c26c90b48c73a7ebf5d913a93 (MD5) Previous issue date: 2017-08-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho tem como proposta o desenvolvimento de um dispositivo de medição de ruído utilizando componentes e dispositivos eletroeletrônicos de baixo custo para uso no monitoramento de ruído em ambientes de trabalho. No desenvolvimento e implementação do sistema de medição foram estudas duas proposta de dispositivos, uma com base na plataforma Arduino e outra com base no sistema OpenWrt em conjunto com um roteador. Os circuitos de captação do ruído foram desenvolvidos com base em circuitos de captação de sinais já existentes, identificando o que melhor se adaptou a proposta. O sistema de medição contempla ainda a proposta de operação remota, por meio da telemetria, de forma que o operador possa controlar as medições sem estar no local. Para isso, foi utilizado um módulo Wireless no Arduino e o próprio roteador usado sistema OpenWrt. Os dispositivos de medição propostos podem ser usados tanto para o monitoramento do ruído, como para o registro dos níveis de ruído de forma continua ou em intervalos de tempo predefinidos, possibilitando assim, a obtenção do histórico do ambiente. Para avaliação de desempenho dos dispositivos foi utilizado um sistema de medição de ruído comercial e as especificações e requisitos de normas técnicas. Os resultados mostraram que o dispositivo implementado com base no sistema OpenWrt apresentou um melhor desempenho, principalmente, em relação sua taxa de amostragem que é maior, não necessitando ajustes e a busca de soluções para aumentar da taxa de amostragem verificados no Arduino. / The present work proposes the development of a noise measurement device, using components and electronic devices of low cost for use in the monitoring of noise in work environments. In the implementation of the measuring system were studied two proposals of devices one based on the platform Arduino and another based on the OpenWrt system together with a router. The noise pickup circuits were developed based on existing signal pickup circuits, identifying what best suited the proposal. The measurement system also contemplates the proposal of remote operation, by telemetry, so that the operator can control the measurements without being in place. For this, a wireless module was used in the Arduino and the router itself in the OpenWrt system. The proposed devices can be used both for noise monitoring and recording of noise levels continuously or at predefined time intervals, thus enabling the achievement of environmental history. For performance evaluation of the devices a commercial noise measurement system was used and the specifications and requirements of technical standards. The results showed that the system implemented based on the OpenWrt system presented a better performance, mainly in relation to its sampling rate that is higher, requiring no adjustments and the search for solutions to increase the sampling rate verified in the Arduino.

Orientador: João Antônio Perreira / Resumo: O presente trabalho tem como proposta o desenvolvimento de um dispositivo de medição de ruído utilizando componentes e dispositivos eletroeletrônicos de baixo custo para uso no monitoramento de ruído em ambientes de trabalho. No desenvolvimento e implementação do sistema de medição foram estudas duas proposta de dispositivos, uma com base na plataforma Arduino e outra com base no sistema OpenWrt em conjunto com um roteador. Os circuitos de captação do ruído foram desenvolvidos com base em circuitos de captação de sinais já existentes, identificando o que melhor se adaptou a proposta. O sistema de medição contempla ainda a proposta de operação remota, por meio da telemetria, de forma que o operador possa controlar as medições sem estar no local. Para isso, foi utilizado um módulo Wireless no Arduino e o próprio roteador usado sistema OpenWrt. Os dispositivos de medição propostos podem ser usados tanto para o monitoramento do ruído, como para o registro dos níveis de ruído de forma continua ou em intervalos de tempo predefinidos, possibilitando assim, a obtenção do histórico do ambiente. Para avaliação de desempenho dos dispositivos foi utilizado um sistema de medição de ruído comercial e as especificações e requisitos de normas técnicas. Os resultados mostraram que o dispositivo implementado com base no sistema OpenWrt apresentou um melhor desempenho, principalmente, em relação sua taxa de amostragem que é maior, não necessitando ajustes e a busca de soluções para aumentar da ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present work proposes the development of a noise measurement device, using components and electronic devices of low cost for use in the monitoring of noise in work environments. In the implementation of the measuring system were studied two proposals of devices one based on the platform Arduino and another based on the OpenWrt system together with a router. The noise pickup circuits were developed based on existing signal pickup circuits, identifying what best suited the proposal. The measurement system also contemplates the proposal of remote operation, by telemetry, so that the operator can control the measurements without being in place. For this, a wireless module was used in the Arduino and the router itself in the OpenWrt system. The proposed devices can be used both for noise monitoring and recording of noise levels continuously or at predefined time intervals, thus enabling the achievement of environmental history. For performance evaluation of the devices a commercial noise measurement system was used and the specifications and requirements of technical standards. The results showed that the system implemented based on the OpenWrt system presented a better performance, mainly in relation to its sampling rate that is higher, requiring no adjustments and the search for solutions to increase the sampling rate verified in the Arduino. / Mestre

This thesis focuses on the noise pollution in sow farming. The first part of the thesis theoretically examines topics concerning noise, sow farming and a proper agricultural practice. The other part of the thesis introduces the aim of the work, describes the measuring technology, the locations objects and the method of the whole measuring process. The obtained values are later on shown in the form of graphs and compared with the hygienic limits. With the occurrence of any violation of these limits, an anti-noise action is suggested.