Key areas of noise sources are investigated through comparison of eddy convection velocity and turbulence measurements in three-stream nozzles. A Time-Resolved Doppler Global Velocimetry (TR-DGV) Instrument was applied to the Nozzle Acoustic Test Rig (NATR) at NASA's Aero-Acoustic Propulsion Lab (AAPL) to measure convection velocity. Particle image velocimetry (PIV) measurements provided mean velocity and turbulence intensity. Eddy convection velocity results were obtained from the TR-DGV data for three-stream nozzle configurations using a cross-correlation approach. The three-stream cases included an axisymmetric and an asymmetric nozzle configuration. Results of the VT TR-DGV convection velocity were compared to NASA PIV mean and turbulence intensity data. For the axisymmetric case, areas of high convection velocity and turbulence intensity were found to be from 4 to 6 diameters downstream. Comparison of convection velocity between the axisymmetric and offset case show this same region as the greatest reduction in convection velocity due to the offset. These findings suggest this region along the centerline near the end of the potential core is an important area for noise generation with jets and contribute to the noise reductions seen from three stream offset nozzles. An analysis of a one-dimensional wavepacket model was completed to provide understanding of the effect of the various convection velocities seen in the flow. Comparison of a wavepacket with a convection velocity of 0.6Uj to a wavepacket with a convection velocity of 0.8Uj showed that an increase in convection velocity shifts the wavenumber spectrum to higher wavenumbers as expected. It was also observed that for the higher convection velocity wavepacket, higher frequencies are more acoustically efficient, while mid frequencies are the most efficient radiators in the lower convection velocity case. Using mean velocity, turbulence intensity, and convection velocity areas of likely to generate noise are identified and possible fundamental mechanisms responsible for the noise generation are discussed. / Master of Science

This thesis describes the development and implementation of new computational techniques to predict installation losses for mixed compression inlets and a study of advanced technology nozzles. The new computational techniques have been created to predict drag and total pressure recovery for both axisymmetric and 2-D mixed compression inlet configurations. These inlets are designed for use in aircraft with sustained supersonic cruise capabilities such as the HSCT. The drag and pressure recovery prediction methods have been added to ACSYNT, an aircraft conceptual design program. Also included in this thesis is a survey of the performance of advanced technology nozzles. Axisymmetric and nonaxisymmetric geometries are considered, as are non thrust-vectoring nozzles. Only the internal losses of these nozzles are considered, and these losses are characterized by the thrust coefficient. The results of this survey have also been added to ACSYNT to extend the thrust prediction capabilities of the code. / Master of Science

An important consideration in the design of military aircraft is observability, or how visible an aircraft is to hostile weapons. One area of great importance to overall observability is an aircraft’s infrared signature, particularly the infrared emissions from the exhaust nozzle and plume. This creates the need for accurate modeling of the infrared signatures from these sources as a design aid or for comparison of candidate designs. To that end, a parametric model has been developed based on the General Electric F110-GE-129 jet engine. The basis of the model is a highly flexible Monte-Carlo ray-trace formulation which is capable of simulating real surface behavior, such as specular reflections, and allows for variation of input parameters such as temperature, surface properties, and geometry. For given input parameters, the model predicts the overall infrared signature due to surface radiation from the exhaust nozzle and interior components. It also indicates the relative contribution of each interior surface to the overall signature and predicts the image that would be seen using infrared imaging equipment. The basic principles of the simulation method and the theory behind the application are discussed. Results are presented, primarily in graphical format, and recommendations are made for further work. / Master of Science

A supersonic ejector is used to pump a secondary gas using a supersonic primary gas flow by augmentation of momentum and energy in a variable area duct. The internal compressible flow through an ejector has many complex gas dynamic features, like compressible shear layers and associated shock interactions. In many practical applications, ejectors are operated in the choked flow regimes where higher operating pressure ratios and mass flow rates are encountered. On the other hand, rather low entrainment and subsonic secondary flow dynamics (referred as the mixed regime of operation) dominate the dilution and purging applications of ejectors. The fundamental understanding of the flow dynamics associated with gaseous mixing process in the ejector especially in the mixed operational regime is still unclear. Obtaining a comprehensive understanding of the flow through a supersonic ejector in the mixed regime through experimental investigations is the prime focus of the present study. A new supersonic ejector test facility is designed, fabricated and established in the laboratory during the course of this study. The effects of using different gases in the secondary flow have been investigated. Two novel methods to improve the ejector by enhancing mixing are also implemented. Optical diagnostic tools (Time-resolved Schlieren and laser scattering) and wall static pressure measurements are used to investigate the dynamics of mixing process inside the ejector. State of the art image processing codes are developed to determine the length in the ejector for which the primary and the secondary flows are separate, referred here as the non-mixed length from the results of the flow visualization studies. Exhaustive experiments are carried out on the two dimensional rectangular supersonic ejector by varying the mass flow rates of primary and secondary flows, primary stagnation pressure, for two locations of the nozzle in the ejector. The non-mixed length determined from quantitative flow visualization tools is found to lie within 4.5 to 5.2 times the height of the duct (20 mm). The non-mixed flow length determined from flow visualization studies corroborates well with the wall static pressure measurements. A significant reduction of non-mixed length of about 46.7% is caused by shock wave-boundary layer interactions in the supersonic nozzle at over-expanded conditions. Further, the effects of differences in molecular weight and ratio of specific heats on the performance are also studied using cylindrical supersonic ejector at low entrainment ratios (0.008 to 0.06). In these studies air is used as the primary fluid while argon and helium are used in the secondary flow segment of the ejector. The results indicate that Argon has better entrainment characteristics compared to helium. Two novel supersonic nozzles (the tip rig nozzle and Elliptic Sharp Tipped Shallow lobed nozzle) are also devel- oped to enhance mixing in the ejector. About 30% enhancement of entrainment ratio is observed with the newly designed nozzle geometries. Illustrative numerical simulations are also carried out to complement the experimental studies.

Um método original para a fabricação de microbocais de diamante com perfil convergente-divergente foi desenvolvido neste trabalho. O método de fabricação desenvolvido utiliza deposição de diamante policristalino sobre moldes que posteriormente são removidos. Os moldes utilizados são fios de tungstênio submetidos a um processo de corrosão eletrolítica para gerar o perfil convergente-divergente de bocal. O microbocal de diamante foi fabricado para ser utilizado como controlador e medidor passivo de vazão de fluidos, quando operando em condições críticas de escoamento. Testes de vazão de gás foram realizados, utilizando os microdispositivos fabricados, para determinar os parâmetros de escoamento necessários para a utilização dos microdispositivos como controladores e medidores de vazão de gás. Os parâmetros críticos de escoamento, a saber, a vazão mássica crítica, a razão crítica de pressão e a vazão volumétrica crítica, bem cmo a faixa do número de Reynolds do escoamento e o coeficiente de descarga, foram determinados para todos os microdispositivos. A faixa de variação do número de Reynolds dos escoamentos obtidos foi de 1x10 POT.3-7x10 POT.4. Por exemplo, o microbocal de diamante com o menor diâmetro de garganta (16+/-1)x10mum apresentou vazão mássica crítica de (0,344+006)g/min, vazão volumétrica crítica de (314+/-5)cm POT.3/min e coeficiente de descarga de (1,27+/-0,19). Assim, foram fabricados com sucesso microbobais de diamante com perfil convergente-divergente e foram determinados os parâmetros críticos de escoamento que possibilitam a estes microbocais atuarem como controladores e medidores passsivos de baixo vazão de gás. / In this work an original method for the fabrication of diamond micronozzles with converget-divergent profile is presented. The method uses the deposition of polycrystalline diamond over a mold, which is subsequently removed. The referred molds are tungsten wires patterned by means of an electrolytic etching procedure in a way that the divergent-convergent profile is generated. The main motivation for producing such micronozzles is its application as passive flow controllers and flow meters elements when operating under critical flow conditions. The micronozzles produced here were tested in order to determine the critical flow parameters that are necessary for its operation, as passive flow controllers and flow meters elements. The critical flow parameters (critical mass flow rate, critical pressure ratio and critical volumetric flow rate), the Reynolds number range and the discharge coefficient were determined for all the microdevices produced. The Reynolds number for the microdevices was found to be in the range of 1x10 POT.3-7x10 POT.4. For instance, the diamond micronozzle with smaller throat diameter, (16+/-1)x10mum, presented critical mass flow rate of (0,344+0,006)g/min, critical volumetric flow rate of (314+/-5)cm POT.3/min and discharge coefficient of (1,27+/-0,19). Therefore, diamond micronozzles were successfully fabricated with convergent-divergent profile and the critical flow parameters necessary for its operation, as passive flow controllers and flow meters elements, were determined.

Made available in DSpace on 2017-07-10T17:37:07Z (GMT). No. of bitstreams: 1 Laercio Boschini.pdf: 240477 bytes, checksum: 28b927e334f14c71cfc93aaf1d7a37de (MD5) Previous issue date: 2006-09-29 / The soybean has great economical importance in Brazilian agribusiness, and the cultivation with high profitability, it is necessary the use all available technologies in the market and, among them, it is the application technology of agricultural pesticide, that it looks tirelessly for the best technique of the product biologically active it reaches the objective, providing for the effective control of the harmful plant, insect or mushroom, allowing the plant express all the productive potential, when appropriately nurtured and in good environmental conditions. Due to those needs the present work was carried out in Cascavel PR, in the harvest 2004/2005, using the soybean cultivar CD 202, with the objective evaluating the amount spray deposited on the soybean leaves, varied the flow rate applied and the nozzles types used in the spraying boom, used tracer substance, simulating the physical characteristics of the solutions of the products. To evaluate the spraying distribution, fifteen leaves were collected per plant in different extracts (upper, medium and lower), with the purpose of evaluating the syrup penetration, in agreement with the different beaks and applied volumes. The experimental design was arranged in randomized complete blocks, in factorial arrangement, with four beaks and point of the type single fan, double fan, double fan with air induction and rollowcone and 3 syrup volumes (100, 200 and 300 L ha-1). In agreement with the results obtained and in the conditions that the present work was carried out. - The syrup volume that presented larger depositions, in the different levels was 300 L ha-1. - The spraying that presented larger depositions, in the higher levels plants was the double fan nozzles and, for the medium and lower extracts, was the rollowcone nozzle. - The depositions happened in the thirds medium and lower of the soybeans plants were lower significantly to obtained them in the upper third, independently the and the flow rate that was used. - For larger depositions in the upper third of the soybeans plants, the best combination is to use of double plane jet, with of 300 L. - For larger depositions in the medium and lower third of the soybeans plants, the best combination is to use of rollowcone, with flow rate of 200 or 300 L ha-1 / A cultura da soja tem grande importância econômica no agronegócio brasileiro, sendo que, para seu cultivo com alta rentabilidade, faz-se necessário o uso de todas as tecnologias disponíveis no mercado e, dentre elas, está à tecnologia de aplicação de defensivos agrícolas, que busca incansavelmente a melhor técnica para que o produto biologicamente ativo atinja o alvo, proporcionando controle eficaz da planta daninha, inseto ou fungo, permitindo à planta expressar todo o seu potencial produtivo, quando adequadamente nutrida e em boas condições ambientais. Diante dessas necessidades foi conduzido o presente trabalho no município de Cascavel PR, na safra de 2004/2005, utilizando o cultivar de soja CD 202, com o objetivo de avaliar a quantidade de calda depositada nas folhas da soja, variando o volume de calda aplicada e os tipos de pontas utilizados na barra de pulverização, utilizando-se substância traçadora, simulando as características físicas das soluções de produtos fitossanitários. Para avaliar a distribuição da pulverização, foram coletadas três folhas por planta em diferentes extratos (superior, mediano e inferior), com a finalidade de avaliar a quantidade de depósito de calda, de acordo com as diferentes pontas e volumes aplicados. O delineamento experimental constituiu-se de blocos ao acaso, em arranjo fatorial, compreendendo 4 pontas de pulverização (leque simples, duplo leque, duplo leque com indução de ar e cone vazio) e 3 volumes de calda (100, 200 e 300 L ha-1 ). De acordo com os resultados obtidos e nas condições em que o presente trabalho foi conduzido, concluiu-se que: o volume de calda que apresentou maiores deposições, nos diferentes extratos das plantas de soja foi o de 300 L ha-1; a ponta de pulverização que apresentou maiores deposições no extrato superior das plantas, foi a de duplo leque e, para os extratos mediano e inferior, a ponta cone vazio; as deposições ocorridas nos extratos mediano e inferior das plantas de soja foram significativamente inferiores às obtidas no extrato superior, independentemente da ponta e do volume de aplicação utilizado; para maiores deposições no extrato superior das plantas de soja, a melhor combinação é utilizar pontas duplo leque, com volumes de calda de 300 L ha-1; para maiores deposições no extrato mediano e inferior das plantas de soja, a melhor combinação é utilizar pontas de cone vazio, com volumes de calda de 200 ou 300 L ha-1

Šiame darbe tiriama švarių paviršių paruošimo sūkuriniu pulsuojančiu srautu galimybė. Darbo tikslas: išsiaiškinti švarių paviršių paruošimo galimybę, naudojant vandens srautą, kuriame turbulencijos lėtėjimo dėka sukeliama kavitacija. Darbas sudarytas iš keturių dalių. Pradžioje apibūdinami švarūs paviršiai, jų klasifikacija. Toliau apžvelgiami švarių paviršių paruošimo metodai, problemos. Po to, skaitmeninės simuliacijos būdu, tiriamos sūkurinį pulsuojantį srautą generuojančių purkštukų konstrukcijos. Eksperimentinėje dalyje pateikiami bandymo rezultatai, kuomet iš aliumininės plokštelės šalinamos abrazyvo liekanos, įstrigusios paviršiuje šlifavimo metu. Darbo pabaigoje pateikiamos išvados. Darbo apimtis – 51 psl. teksto be priedų, 36 iliustracijos, 3 lentelės, 13 bibliografinių šaltinių. Atskirai pridedami darbo priedai. / This study investigates the preparation of clean surfaces with pulsating vortex flow option. The aim of work: to determine the possibility of clean surface preparation using a water flow with generated cavitation. The work consists of four parts. At the start of the work characterized clean surfaces and their classification. The following provides an overview of clean surface preparation methods, problems. After that, the digital simulation method investigated vortex-generating jets pulsating flow structures. In the experimental part are presented the test results, when the aluminum plate is disposed abrasive residues trapped on the surface of the grinding time. At the end of the work there are given conclusions. Work size - 51 text pages without appendixes, 36 figures, 3 tables, 13 bibliographical sources.

Submitted by Matheus Mereb Negrisoli (matheusmnegrisoli@gmail.com) on 2018-09-20T20:48:08Z No. of bitstreams: 1 DISSERTAÇÃO FINAL - MM NEGRISOLI.pdf: 2968166 bytes, checksum: 8b6262aac754b787c2215852bc6fca23 (MD5) / Approved for entry into archive by Maria Lucia Martins Frederico null (mlucia@fca.unesp.br) on 2018-09-21T12:07:59Z (GMT) No. of bitstreams: 1 negrisoli_mm_me_botfca.pdf: 2968166 bytes, checksum: 8b6262aac754b787c2215852bc6fca23 (MD5) / Made available in DSpace on 2018-09-21T12:07:59Z (GMT). No. of bitstreams: 1 negrisoli_mm_me_botfca.pdf: 2968166 bytes, checksum: 8b6262aac754b787c2215852bc6fca23 (MD5) Previous issue date: 2018-07-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Para o controle da ferrugem asiática da soja (FAS) é necessário a otimização da tecnologia de aplicação de modo a promover incrementos na cobertura da pulverização na região do baixeiro da cultura e melhorar a distribuição das gotas no dossel. Assim, o objetivo deste trabalho foi avaliar o efeito de pontas de jato plano com diferentes inclinações e volumes de calda na otimização da pulverização de fungicidas na cultura da soja, no controle da FAS e sobre a produtividade da cultura. Para isso, foram conduzidos três experimentos durante as safras 2016/17 e 2017/18 em Botucatu, SP envolvendo três pontas de pulverização: jato plano (AXI), jato plano duplo (JGT) e jato plano inclinado (Defy3D) em dois volumes de calda (125 e 250 L ha-1). No experimento 1 foi avaliado em mesa de distribuição volumétrica a uniformidade da distribuição volumétrica dos tratamentos e o espectro das gotas da pulverização pelo medidor de tamanho de partículas em tempo real. No experimento 2 foi realizado a análise quali-quantitativa da pulverização, por meio da deposição da calda na cultura com o marcador Azul Brilhante, e a cobertura da pulverização dos tratamentos em alvos artificiais e natural. Por fim, no experimento 3 foi avaliado a severidade e incidência da FAS, de modo a se determinar a eficácia de controle dos tratamentos, assim como seu efeito sobre a produtividade da cultura da soja. Em ambos os volumes de calda, a ponta JGT obteve menor coeficiente de variação e melhor distribuição da pulverização. Todas as pontas nos volumes de calda mantiveram valores de CV abaixo de 7%, considerado aceitável para os padrões internacionais. O DMV (µm), SPAN e porcentagem de gotas inferiores a 100 µm foram influenciados pela adição do fungicida associado ao adjuvante à calda. Independente da ponta de pulverização e volume de calda, a penetração das gotas da pulverização no dossel foi prejudicada em R2, com baixos valores de deposição e cobertura na parte inferior da planta. Todas as pontas e volumes avaliados promoveram controle eficaz da doença, não havendo incremento no controle com a utilização de um volume de calda maior ou inclinação do jato. Mesmo com redução significativa da deposição e cobertura na região inferior, os tratamentos foram eficazes na redução da severidade da doença. O nível de controle, apesar de parecer eficaz quanto ao número de pústulas e cálculo da área abaixo da curva de progresso da doença (AACPD) pode não ser suficiente para assegurar maior produtividade. A correta definição do volume de calda, principalmente com relação aos diferentes estádios fenológicos da cultura, influencia grandemente a deposição e cobertura da pulverização. / For the control of Asian soybean rust (SBR), an optimization of the application technology is necessary in order to improve spray coverage in the lower part of the crop as well as the spray drops distribution uniformity. Thus, the objective of this study was to evaluate the effect of flat fan nozzles with different inclinations and spray volumes on the optimization of fungicide spraying in the soybean crop, as well as on the ASR control and its effect on the crop yield. For this purpose, three experiments were conducted during 2016/17 and 2017/18 crop seasons in Botucatu, SP. Three spray nozzles were evaluated: flat fan (AXI), double flat fan (JGT) and inclined flat fan (Defy 3D) with two spray volumes (125 e 250 L ha-1). In Experiment 1, the spray distribution uniformity of the treatments was evaluated in a patternator table and the spray droplet spectrum was assessed by a real-time particle size analyzer. In Experiment 2, a quali-quantitative analysis of the spraying was evaluated, assessing spray deposits on the crop with Brilliant Blue tracer, and the spray coverage of the treatments on artificial and natural targets. Lastly, in Experiment 3, ASR incidence and severity were evaluated, in order to determine the treatment control efficacy and its effect on the soybean yield. In both spray volumes, the JGT nozzle provided lowest variation coefficient and better spray distribution. All the spray nozzles and volumes kept CV values below 7%, considered acceptable by international standards. The VMD (µm), SPAN and percentage of droplets smaller than 100 µm were influenced by the addition of fungicide associated with adjuvant to the spray mixture. Irrespective of the spray nozzle and volume, the penetration of the spray droplets into the crop canopy was impaired at R2, with low deposition and coverage in the lower part of the plant. All the spray nozzles and volumes promoted effective control of the disease, with no increment in function of a larger spray volume or spray inclination. Even with significant reduction on deposition and spray coverage on the lower region, the treatments were efficient reducing the disease severity. The level of control, although it seems effective regarding pustules number and area under the disease progress curve calculation, might not be enough to ensure greater productivity. The correct spray volume definition, especially in respect to the different crop phenological stages influences greatly in the deposition and spray coverage.

Made available in DSpace on 2014-10-09T12:43:43Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:05Z (GMT). No. of bitstreams: 1 06657.pdf: 7227137 bytes, checksum: 98d04613dee6fef51753ac299fba0661 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Um método original para a fabricação de microbocais de diamante com perfil convergente-divergente foi desenvolvido neste trabalho. O método de fabricação desenvolvido utiliza deposição de diamante policristalino sobre moldes que posteriormente são removidos. Os moldes utilizados são fios de tungstênio submetidos a um processo de corrosão eletrolítica para gerar o perfil convergente-divergente de bocal. O microbocal de diamante foi fabricado para ser utilizado como controlador e medidor passivo de vazão de fluidos, quando operando em condições críticas de escoamento. Testes de vazão de gás foram realizados, utilizando os microdispositivos fabricados, para determinar os parâmetros de escoamento necessários para a utilização dos microdispositivos como controladores e medidores de vazão de gás. Os parâmetros críticos de escoamento, a saber, a vazão mássica crítica, a razão crítica de pressão e a vazão volumétrica crítica, bem cmo a faixa do número de Reynolds do escoamento e o coeficiente de descarga, foram determinados para todos os microdispositivos. A faixa de variação do número de Reynolds dos escoamentos obtidos foi de 1x10 POT.3-7x10 POT.4. Por exemplo, o microbocal de diamante com o menor diâmetro de garganta (16+/-1)x10mum apresentou vazão mássica crítica de (0,344+006)g/min, vazão volumétrica crítica de (314+/-5)cm POT.3/min e coeficiente de descarga de (1,27+/-0,19). Assim, foram fabricados com sucesso microbobais de diamante com perfil convergente-divergente e foram determinados os parâmetros críticos de escoamento que possibilitam a estes microbocais atuarem como controladores e medidores passsivos de baixo vazão de gás. / In this work an original method for the fabrication of diamond micronozzles with converget-divergent profile is presented. The method uses the deposition of polycrystalline diamond over a mold, which is subsequently removed. The referred molds are tungsten wires patterned by means of an electrolytic etching procedure in a way that the divergent-convergent profile is generated. The main motivation for producing such micronozzles is its application as passive flow controllers and flow meters elements when operating under critical flow conditions. The micronozzles produced here were tested in order to determine the critical flow parameters that are necessary for its operation, as passive flow controllers and flow meters elements. The critical flow parameters (critical mass flow rate, critical pressure ratio and critical volumetric flow rate), the Reynolds number range and the discharge coefficient were determined for all the microdevices produced. The Reynolds number for the microdevices was found to be in the range of 1x10 POT.3-7x10 POT.4. For instance, the diamond micronozzle with smaller throat diameter, (16+/-1)x10mum, presented critical mass flow rate of (0,344+0,006)g/min, critical volumetric flow rate of (314+/-5)cm POT.3/min and discharge coefficient of (1,27+/-0,19). Therefore, diamond micronozzles were successfully fabricated with convergent-divergent profile and the critical flow parameters necessary for its operation, as passive flow controllers and flow meters elements, were determined.