3 resultados para Transporte urbano - Planejamento - Modelos matemáticos
em Repositório Institucional da Universidade Tecnológica Federal do Paraná (RIUT)
Resumo:
The urban mobility has in the bicycle its symbol of the most environmentally sustainable modal of transportation of the planet, title conferred by the United Nations Organization (ONU). Nevertheless, the cities suffer with the traffic jam caused by the automobile fleet growth, what implies in a larger displacement time, injuries to the environment, to financials and to the quality of life. In order to build in a sustainable way the urban mobility, public policies are necessary to encourage the preferential usage, by the society, of the mass transit or the non-motorized type of transportation. Objecting cooperate with the public power and the civil society, this study intents to, through an analysis about the UFPR Extension Program - CICLOVIDA, propose a sustainable urban mobility public policy development, with emphasis in the bicycle´s usage. eferentially, it is discussed concepts such as Society, State and Government as well as public policies, which go in cycles to the State´s and Government´s responsibilities; and are presented the Sustainable Urban Mobility Public Policies (PPMUS) in Brazil. Also, it is debated about the transport by bicycle as an option to the sustainable mobility. Methodologically, the study is of an empiric-social nature, with the application of both qualitative and observational methods, what characterizes as an exploratory level of research, with the researcher´s involvement in the participant form, due to her acting on the Program. Regarding the research lineation, it was used the bibliographic and documental form as well as case study, by means of the nonparametric sampling by accessibility or convenience. Related to the data collection technique, it was used structured interviews with self-applied questionnaires and natural participant observation. Aligned with the research´s objective and matter, the outcome confirmed that the Extension Program CICLOVIDA of the Federal University of Paraná (UFPR) may effectively contribute in the development of a PPMUS proposal with emphasis in the bicycle usage. Thus, it was built a political proposal with a free form writing, objecting subsidize policies both institutional as public MUS through the bicycle usage and therefore, support the mobility, also contributing to the sustainability and to the public development planning.
Resumo:
Gas-liquid two-phase flow is very common in industrial applications, especially in the oil and gas, chemical, and nuclear industries. As operating conditions change such as the flow rates of the phases, the pipe diameter and physical properties of the fluids, different configurations called flow patterns take place. In the case of oil production, the most frequent pattern found is slug flow, in which continuous liquid plugs (liquid slugs) and gas-dominated regions (elongated bubbles) alternate. Offshore scenarios where the pipe lies onto the seabed with slight changes of direction are extremely common. With those scenarios and issues in mind, this work presents an experimental study of two-phase gas-liquid slug flows in a duct with a slight change of direction, represented by a horizontal section followed by a downward sloping pipe stretch. The experiments were carried out at NUEM (Núcleo de Escoamentos Multifásicos UTFPR). The flow initiated and developed under controlled conditions and their characteristic parameters were measured with resistive sensors installed at four pipe sections. Two high-speed cameras were also used. With the measured results, it was evaluated the influence of a slight direction change on the slug flow structures and on the transition between slug flow and stratified flow in the downward section.
Resumo:
Centrifugal pumps are vastly used in many industrial applications. Knowledge of how these components behave in several circumstances is crucial for the development of more efficient and, therefore, less expensive pumping installations. The combination of multiple impellers, vaned diffusers and a volute might introduce several complex flow characteristics that largely deviate from regular inviscid pump flow theory. Computational Fluid Dynamics can be very helpful to extract information about which physical phenomena are involved in such flows. In this sense, this work performs a numerical study of the flow in a two-stage centrifugal pump (Imbil ITAP 65-330/2) with a vaned diffuser and a volute. The flow in the pump is modeled using the software Ansys CFX, by means of a multi-block, transient rotor-stator technique, with structured grids for all pump parts. The simulations were performed using water and a mixture of water and glycerin as work fluids. Several viscosities were considered, in a range between 87 and 720 cP. Comparisons between experimental data obtained by Amaral (2007) and numerical head curves showed a good agreement, with an average deviation of 6.8% for water. The behavior of velocity, pressure and turbulence kinetic energy fields was evaluated for several operational conditions. In general, the results obtained by this work achieved the proposed goals and are a significant contribution to the understanding of the flow studied.