Blade design and forming for fans using finite elements

The necessity of adapting the standardized fan models to conditions of higher temperature has emerged due to the growth of concerning referring to the consequences of the gas expelling after the Mont Blanc tunnel accident in Italy and France, where even though, with 100 fans in operation, 41 people died. However, since then, the defied solutions have pointed to aerodynamic disadvantages or have seemed nonappropriate in these conditions. The objective of this work is to present an alternative to the market standard fans considering a new technology in constructing blades. This new technology introduces the use of the stainless steel AISI 409 due to its good adaptation to temperatures higher than 400°C, particularly exposed to temperatures of gas exhaust from tunnels in fire situation. Furthermore, it presents a very good resistance to corrosion and posterior welding and pressing, due to its alloyed elements. The innovation is centered in the process of a deep drawing of metallic shells and posterior welding, in order to keep the ideal aerodynamic superficies for the fan ideal performance. On the other hand, the finite element method, through the elasto-plastic software COSMOS permitted the verification of the thickness and structural stability of the blade in relation to the aerodynamic efforts established in the project. In addition, it is not advisable the fabrication of blades with variable localized thickness not even, non-uniform ones, due to the verified concentration of tensions and the difficulties observed in the forming. In this way, this study recommends the construction of blades with uniform variations of thickness. © 2007 Springer.

A methodology and a tool to design of mixed-signal technology

This paper presents a tool box developed to read files describing a SIMULINK® model and translates it into a structural VHDL-AMS description. In translation process, all files and directory structures to simulate the translated model on SystemVision™ environment is generate. The tool box named MS2SV was tested by three models of commercially available digital-to-analogue converters. All models use the R2R ladder network to conversion, but the functionality of these three components is different. The methodology of conversion of the model is presents together with sort theory about R-2R ladder network. In the evaluation of the translated models, we used a sine waveform input signal and the waveform generated by D/A conversion process was compared by FFT analysis. The results show the viability of this type of approach. This work considers some of challenges set by the electronic industry for the further development of simulation methodologies and tools in the field of mixed-signal technology. © 2007 IEEE.

Power losses analysis and cooling system design of three topologies of multilevel inverters

This paper presents the comparison of three topologies of multilevel inverters applied to drive an induction motor of 500 kVA/4.16 kV. The multilevel inverters analyzed are: a neutral point clamped inverter, a symmetrical cascaded multilevel inverter and a hybrid asymmetrical cascaded multilevel inverter. The performance indexes used in the comparison are total harmonic distortion, first order distortion factor, semiconductors power losses distribution and heat-sink volume. The comparison is developed with the purpose of finding the efficiency and the heat-sink volume where the three systems present the same output filter. ©2008 IEEE.

Chaos suppression in NEMs resonators by using nonlinear control design

In this work the chaotic behavior of a micro-mechanical resonator with electrostatic forces on both sides is suppressed. The aim is to control the system in an orbit of the analytical solution obtained by the Method of Multiple Scales. Two control strategies are used for controlling the trajectory of the system, namely: State Dependent Riccati Equation (SDRE) Control and Optimal Linear Feedback Control (OLFC). The controls proved effectiveness in controlling the trajectory of the system. Additionally, the robustness of each strategy is tested considering the presence of parametric errors and measurement noise in control. © 2012 American Institute of Physics.

Design of a labVIEW system applied to predictive maintenance

The implementation of vibration analysis techniques based on virtual instrumentation has spread increasingly in the academic and industrial branch, since the use of any software for this type of analysis brings good results at low cost. Among the existing software for programming and creation of virtual instruments, the LabVIEW was chosen for this project. This software has good interface with the method of graphical programming. In this project, it was developed a system of rotating machine condition monitoring. This monitoring system is applied in a test stand, simulating large scale applications, such as in hydroelectric, nuclear and oil exploration companies. It was initially used a test stand, where an instrumentation for data acquisition was inserted, composed of accelerometers and inductive proximity sensors. The data collection system was structured on the basis of an NI 6008 A/D converter of National Instruments. An electronic circuit command was developed through the A/D converter for a remote firing of the test stand. The equipment monitoring is performed through the data collected from the sensors. The vibration signals collected by accelerometers are processed in the time domain and frequency. Also, proximity probes were used for the axis orbit evaluation and an inductive sensor for the rotation and trigger measurement. © (2013) Trans Tech Publications, Switzerland.

Intencionalidade e indeterminação interpretativa no design de produto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise da percepção de desconforto/conforto e antropometria em calçados femininos: uma abordagem do design ergonômico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Variações nos níveis de elementos minerais após aplicações de 2,4-D em progênies de Eucalyptus grandis

Pós-graduação em Ciência Florestal - FCA

Intervenção ergonômica e o uso da simulação computacional na concepção de produtos: o design de uma plantadora mecanizada de mandioca

Pós-graduação em Design - FAAC

Economic design of Shewhart control charts for monitoring autocorrelated data with skip sampling strategies

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cogeneration design problem Computational complexity analysis and solution through an expert system

Purpose - The purpose of this paper is twofold: to analyze the computational complexity of the cogeneration design problem; to present an expert system to solve the proposed problem, comparing such an approach with the traditional searching methods available.Design/methodology/approach - The complexity of the cogeneration problem is analyzed through the transformation of the well-known knapsack problem. Both problems are formulated as decision problems and it is proven that the cogeneration problem is np-complete. Thus, several searching approaches, such as population heuristics and dynamic programming, could be used to solve the problem. Alternatively, a knowledge-based approach is proposed by presenting an expert system and its knowledge representation scheme.Findings - The expert system is executed considering two case-studies. First, a cogeneration plant should meet power, steam, chilled water and hot water demands. The expert system presented two different solutions based on high complexity thermodynamic cycles. In the second case-study the plant should meet just power and steam demands. The system presents three different solutions, and one of them was never considered before by our consultant expert.Originality/value - The expert system approach is not a "blind" method, i.e. it generates solutions based on actual engineering knowledge instead of the searching strategies from traditional methods. It means that the system is able to explain its choices, making available the design rationale for each solution. This is the main advantage of the expert system approach over the traditional search methods. On the other hand, the expert system quite likely does not provide an actual optimal solution. All it can provide is one or more acceptable solutions.

The study of cardiovascular risk in adolescents - ERICA: rationale, design and sample characteristics of a national survey examining cardiovascular risk factor profile in Brazilian adolescents

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Design de Relações entre tecnologias amigáveis e sociabilidades virtuais: um novo campo de investigação para o Design

The Digital Age, with its new interactive and converging technologies, stimulates original forms of sociability, which are interconnected, intercommunicating and virtualized through hyperscreens. Another kind of interaction arises from the digitization and new speeds of contemporary communicative process. With the new order of knowledge, it is now possible to transgress the limits of physical space and linear time sequence, through the collective development of content through such telematics networks. Youth gives voice to a new type of user, or a social actor, whose thinking is connected to other communication habits, consolidating singular cultural standards, demanding new languages and skills. Here, we address the nature of this Design of new relations, interactions, behaviors and social systems that emerge in the so called Information Society.

Laboratório de design solidário - LABSOL: projeto de extensão em design na perspectiva da geração de trabalho e renda

Introdução: Na sociedade contemporânea costuma-se associar Design ao consumo de luxo, entretanto o design encontra-se aplicado a todos os objetos, do automóvel ao clips, todavia o Design parece estar sempre atrelado à sociedade de consumo, à indústria a serviço do capital e das relações de subordinação e expropriação a ele atrelado. Assim faz-se necessário despertar no aluno do curso de Design a possibilidade da aplicação de seu conhecimento a serviço de uma sociedade mais democrática e solidária, de não apenas produzir a serviço do capital, mas pensar de forma mais abrangente, considerando o bem comum. Objetivos: O Labsol, desde 2007, procura: Otimizar, revitalizar e qualificar a produção artesanal através dos conceitos de ecodesign, sustentabilidade e economia solidária, tendo em vista a auto sustentabilidade das comunidades produtoras. Desenvolver projetos e ações que promovam encontros entre o Design e o patrimônio cultural do artesanato. Preocupar-se com a qualificação do produto artesanal e sua inserção no mercado, tendo em vista a auto sustentabilidade das comunidades produtoras. Métodos: A formação dos integrantes do LabSol é continua e baseada em três conceitos fundamentais: sustentabilidade, economia solidária e eco design. As ações se dão a partir do convite de uma comunidade de artesãos na perspectiva da qualificação estética ou produtiva de seus trabalhos e a melhoria da geração de renda. Utiliza-se o método empírico, de caráter prático, através de estudo de caso. Em uma visita aprende-se métodos e técnicas utilizados pela comunidade, e de volta à sede, faz-se revisão bibliográfica e utiliza-se a metodologia do projeto em design para melhoria das técnicas produção, o redesenho de produtos e a geração de novos objetos de design. Construídos modelos e protótipos e avaliado seu potencial de comercialização são submetidos a aprovação da comuni-dade através de oficinas. O diferencial no trabalho do LabSol se dá na maneira que os projetos são entregues aos grupos. Entende-se todo o processo como um aprendizado de mão dupla, da troca de saberes, onde os membros do laboratório aprendem da comunidade dados de sua cultura e de seus modos de fazer, em contrapartida novos produtos são levados de volta a comunidade, entendidos como mais um dado cultural posto a disposição da comunidade podendo ou não ser por ela incorporado. Resultados: Com mais de 20 grupos atendidos, e centenas de produtos de eco design, as ações o LabSol resultam na pesquisa de eco design, materiais, técnicas, métodos e de novas tecnologias sociais, gerando um número significativo de publicações e exposições de divulgação. Tem recebido graduandos de relações públicas e engenharia de produção, a junção de saberes tem permitido um aprimoramento na qualidade de atendimento ás comunidades.