Harry Schulz

No presente trabalho foram realizadas simulacoes numericas, para um ciclo de mare semidiurna, do escoamento de um trecho do rio Matapi, afluente do rio Amazonas, proximo as cidades de Santana e Macapa. O objetivo geral foi avaliar o comportamento espacial e temporal do escoamento e de potenciais fontes poluentes na foz do rio Matapi e confluencia com o rio Amazonas. O trecho em questao envolve o Distrito Industrial de Santana, regiao de potencial ocorrencia de derrames de compostos poluentes. Foram simuladas as condicoes dos escoamentos naturais causadas por movimentos de mares e que influenciam fortemente o comportamento dos constituintes passivos da agua. Os resultados sao apresentados na forma de campos hidrodinâmicos em regime transiente e campos de concentracao de poluentes associados aos primeiros. As informacoes sao uteis para observar a permanencia de poluentes no trecho e devem servir de base para o planejamento de disposicao de aguas residuarias industriais nessa regiao, o...

No presente trabalho foram realizadas simulacoes numericas, para um ciclo de mare semidiurna, do escoamento de um trecho do rio Matapi, afluente do rio Amazonas, proximo as cidades de Santana e Macapa. O objetivo geral foi avaliar o comportamento espacial e temporal do escoamento e de potenciais fontes poluentes na foz do rio Matapi e confluencia com o rio Amazonas. O trecho em questao envolve o Distrito Industrial de Santana, regiao de potencial ocorrencia de derrames de compostos poluentes. Foram simuladas as condicoes dos escoamentos naturais causadas por movimentos de mares e que influenciam fortemente o comportamento dos constituintes passivos da agua. Os resultados sao apresentados na forma de campos hidrodinâmicos em regime transiente e campos de concentracao de poluentes associados aos primeiros. As informacoes sao uteis para observar a permanencia de poluentes no trecho e devem servir de base para o planejamento de disposicao de aguas residuarias industriais nessa regiao, o...

This paper presents results of experimental studies on the behavior of free surface flows in a stepped chute and in a hydraulic jump. The proposed methodology involves the acquisition of high frequency data by means of ultrasonic sensors. This proposal allowed to assess mean profiles of the free surface, characteristic quantities of the profiles (inception point, depth at the inception point, transition length, etc.) and quantities that characterize the turbulence near the free surface. The method provided excellent results for the monophasic and biphasic flows. It was possible to establish relationships between different variables such as the inception points of aeration, mean depths, and maximum depth. The results concerning the turbulence regions showed growth and decay of turbulence. Evaluations of constants related to the turbulence model k were also obtained

This paper presents results of experimental studies on the behavior of free surface flows in a stepped chute and in a hydraulic jump. The proposed methodology involves the acquisition of high frequency data by means of ultrasonic sensors. This proposal allowed to assess mean profiles of the free surface, characteristic quantities of the profiles (inception point, depth at the inception point, transition length, etc.) and quantities that characterize the turbulence near the free surface. The method provided excellent results for the monophasic and biphasic flows. It was possible to establish relationships between different variables such as the inception points of aeration, mean depths, and maximum depth. The results concerning the turbulence regions showed growth and decay of turbulence. Evaluations of constants related to the turbulence model k were also obtained

RESUMO – Uma armadilha de sedimentos foi construída em laboratório, com o objetivo de auxiliar no estudo de transporte de sedimentos e assoreamento de reservatórios. O sistema de lançamento de sedimentos desenvolvido permite uma descarga constante de até 15 g/s; e as paredes de acrílico da armadilha possibilitam acompanhamento e filmagem da evolução do assoreamento de diferentes pontos de vista. O comportamento do fluido no interior da armadilha, para a vazão afluente estabelecida de 2 L/s e ainda sem adição de sedimentos, deve ser analisado para que o início do processo do assoreamento seja entendido. Com esse objetivo, o escoamento é visualizado através de campos de velocidade horizontais obtidos com técnica de velocimetria a laser. Esses campos têm também como propósito a validação da simulação numérica hidrodinâmica do escoamento na armadilha, etapa seguinte a este trabalho e fundamental para o início da simulação do assoreamento. ABSTRACT – A sand trap was built in a laboratory...

RESUMO – Uma armadilha de sedimentos foi construída em laboratório, com o objetivo de auxiliar no estudo de transporte de sedimentos e assoreamento de reservatórios. O sistema de lançamento de sedimentos desenvolvido permite uma descarga constante de até 15 g/s; e as paredes de acrílico da armadilha possibilitam acompanhamento e filmagem da evolução do assoreamento de diferentes pontos de vista. O comportamento do fluido no interior da armadilha, para a vazão afluente estabelecida de 2 L/s e ainda sem adição de sedimentos, deve ser analisado para que o início do processo do assoreamento seja entendido. Com esse objetivo, o escoamento é visualizado através de campos de velocidade horizontais obtidos com técnica de velocimetria a laser. Esses campos têm também como propósito a validação da simulação numérica hidrodinâmica do escoamento na armadilha, etapa seguinte a este trabalho e fundamental para o início da simulação do assoreamento. ABSTRACT – A sand trap was built in a laboratory...

Este trabalho expõe o uso de velocimetria a laser no estudo de detalhes do fenômeno da turbulência e na obtenção de padrões do escoamento de fluidos. A descrição dessa técnica não intrusiva é feita a partir de sua aplicação em duas pesquisas desenvolvidas: a turbulência gerada por grades oscilantes e o assoreamento de um modelo físico de reservatório. No tanque de grades oscilantes, a velocimetria possibilitou a observação e a quantificação de características importantes da turbulência. No reservatório, a técnica auxiliou na comparação dos dados de assoreamento com sua simulação feita em um modelo computacional. A concordância dos resultados apontou para as vantagens do uso de procedimentos numéricos para estudo e estimativa de assoreamento em reservatórios. Tanto na pesquisa acadêmica de turbulência, como na pesquisa aplicada de sedimentação, ambas desenvolvidas em laboratório, a velocimetria a laser mostrou-se uma ferramenta essencial. Palavras-chave: Velocimetria a laser. Velocim...

Este trabalho expõe o uso de velocimetria a laser no estudo de detalhes do fenômeno da turbulência e na obtenção de padrões do escoamento de fluidos. A descrição dessa técnica não intrusiva é feita a partir de sua aplicação em duas pesquisas desenvolvidas: a turbulência gerada por grades oscilantes e o assoreamento de um modelo físico de reservatório. No tanque de grades oscilantes, a velocimetria possibilitou a observação e a quantificação de características importantes da turbulência. No reservatório, a técnica auxiliou na comparação dos dados de assoreamento com sua simulação feita em um modelo computacional. A concordância dos resultados apontou para as vantagens do uso de procedimentos numéricos para estudo e estimativa de assoreamento em reservatórios. Tanto na pesquisa acadêmica de turbulência, como na pesquisa aplicada de sedimentação, ambas desenvolvidas em laboratório, a velocimetria a laser mostrou-se uma ferramenta essencial. Palavras-chave: Velocimetria a laser. Velocim...

Results generated by solving the one-dimensional mass transfer equation for gas transfer in the near-surface region of water bodies are compared with experimental data The data were obtained in temperature controlled cylindrical water tanks in which agitation was induced by propellers. Mass transfer was studied for methane, eurylene, and acetylene The results show good agreement between theory and data for a broad range of agitation conditions A theoretical power law approach between two relevant nondimensional groups is observed in this range, but deviations from this trend may be observed for both very low and very high agitations. The fact that theory and data coincide within a range of agitation conditions induces one to calculate theoretical trends for other relevant parameters for mterfacial mass-transfer, as boundary layer thickness and concentration fluctuation peak position Results are compared with propositions of other sources, showing that the formulation leads to conclu...

Food residues from residential waste were obtained through curbside collection in te City of São Carlos, SP, Brazil, and were processed and characterized chemically and microbiologically. The results showed absence of mycotoxins, heavy metals, organochlorine pesticides and pathogenic microorganisms. The nutritional composition, granulometry, smell and taste of the resulting component, termed as "Feed on Ingredient from Food Residues (FIFR)", show its potential as an ingredient in brolier chicken feed, in association with other ingredients, such as corn bran and soy bean bran.

The behavior of the free surface in skimming flows along stepped chutes is investigated for the step ratio 1V:1H. Data were collected using high frequency ultrasound probes. The measurements included mean surface profiles, statistical parameters related to the surface position, aeration inception point, water depth at the inception point and transition length. The measurements were related to turbulence parameters at the free surface. The measurement methodology was adequate for both the black-water and the white-water regions. Characteristic relations are developed for different variables defined for skimming flows. The results demonstrate regions of increasing and decreasing turbulence in the transition between the black-water and the white-water flows, and a region of decay of turbulence, related to the distance needed to attain the quasi-uniform flow of the white-water.

O presente estudo versa sobre a variação espacial-temporal de parâmetros da qualidade da água e foi realizado em quatro rios estuarinos próximos às cidades de Macapá e Santana (AP) - Brasil, e trata especialmente de poluição microbiológica (coliformes fecais - CF), delineada em pesquisa de campo ocorrida entre o período de setembro de 1999 a setembro de 2002. A análise espacial-temporal dos parâmetros bacteriológicos mostrou um significativo grau de comprometimento e degradação ambiental em algumas seções de coleta. A obtenção de faixas de concentração mostrou-se importante para avaliar as freqüências e distribuições estatísticas de parâmetros da qualidade da água, principalmente para indicar riscos à saúde pública e aos ecossistemas aquáticos. Finalmente, devido a quase completa ausência de informações hidrodinâmica e climática sistematizada, a abordagem fundamentou-se na utilização de análise estatística. Contudo, verificou-se uma tendência de aderência dos dados a uma distribuiçã...

The prediction of sedimentation is an important aspect of reservoir planning and design. Such prediction can be supported by detailed analyses of flow patterns and sediment transport inside reservoirs, usually conducted through numerical simulation. This research compares laboratorial sedimentation experiments in a shallow reservoir and predictions using a 2D numerical model with depth-average Navier-Stokes equations and a sediment transport code. A number of sediment transport equations were tested, among which the Engelund and Fredsøe formulation better represented the measured data. Flows without sediment transport or without bed dunes could be simulated using Smagorinski's turbulence model, while flows with sediment occurring over dunes needed the use of a constant turbulent viscosity. The similarity obtained between experimental data and numerical results, for both flow pattern and sediment deposition, confirms that the models and numerical codes used in this work are usef...

... f = − 4Dh k1L + 4Dh k1L ( )2 + 64 k1k2 sina F4 1 hc h1 ( )2 sina + Dh L ( ) √ , (9) ... III 267.76 6.87 254.20 215.62 Figure 3 Stilling basin lengths, data of Peterka (1984) and Eq. (7b) adjusted for j ¼ I, II, III, IV 332 ALA Simo˜es et al. Journal of Hydraulic Research Vol. 48, No. ...

ABSTRACT The purpose of this study was to evaluate the use of leftover food as chicken feed destined for poultry farms, obtained through selective collection in a popular neighborhood in the city of São Carlos, SP, Brazil, ground up, sterilized, dried and characterized chemically and microbiologically. The final component, called food leftover feed ingredient (FLFI), was tested on chickens as a chicken feed ingredient in proportions of 5, 10, 15, 20 and 25% mixed with corn and soybean bran and other ingredients. The characterization of the FLFI revealed the absence of mycotoxins, heavy metals, organochlorined pesticides and pathogenic microorganisms. The product showed a high metabolizable energy value (3.483 kcal kg-1), good protein value (12%) and various minerals. The vitamin content was found to be low, as were some minerals and amino acids. The results revealed that the inclusion of up to 20% of FLFI did not modify the chickens' performance, as indicated by the indices of feed consumption, weight gain and food conversion.

The mathematical treatment of phenomena that oscillate randomly in space and time, generating the so called “statistical governing equations”, is still a difficult task for scientists and engineers. Turbulence in fluids is an example of such phenomena, which has great influence on the transport of physical proprieties by the fluids, but which statistical quantification is still strongly based on ad hoc models. In turbulent flows, parameters like velocity, temperature and mass concentration oscillate continuously in turbulent fluids, but their detailed behavior, considering all the possible time and space scales, has been considered difficult to be reproduced mathematically since the very beginning of the studies on turbulence. So, statistical equations were proposed and refined by several authors, aiming to describe the evolution of the “mean values” of the different parameters (see a description, for example, in Monin & Yaglom, 1979, 1981). The governing equations of fluid motion are nonlinear. This characteristic imposes that the classical statistical description of turbulence, in which the oscillating parameters are separated into mean functions and fluctuations, produces new unknown parameters when applied on the original equations. The generation of new variables is known as the “closure problem of statistical turbulence” and, in fact, appears in any phenomena of physical nature that oscillates randomly and whose representation is expressed by nonlinear conservation equations. The closure problem is described in many texts, like Hinze (1959), Monin & Yaglom (1979, 1981), and Pope (2000), and a general form to overcome this difficulty is matter of many studies. As reported by Schulz et al. (2011a), considering scalar transport in turbulent fluids, an early attempt to theoretically predict RMS profiles of the concentration fluctuations using “ideal random signals” was proposed by Schulz (1985) and Schulz & Schulz (1991). The authors used random square waves to represent concentration oscillations during mass transfer across the air-water interface, and showed that the RMS profile of the concentration fluctuations may be expressed as a function of the mean concentration profile. In other words, the mean concentration profile helps to know the RMS profile. In these studies, the authors did not consider the effect of diffusion, but argued that their equation furnished an upper limit for the normalized RMS value, which is not reached when diffusion is taken into account. The random square waves were also used by Schulz et al. (1991) to quantify the so called “intensity of segregation” in the superficial boundary layer formed during mass transport, for which the explanations of segregation scales found in Brodkey (1967) were used. The time constant of the intensity of segregation, as defined in the classical studies of Corrsin (1957, 1964), was used to correlate the mass transfer coefficient across the water surface with more usual parameters, like the Schmidt number and the energy dissipation rate. Random square waves were also applied by Janzen (2006), who used the techniques of Particle Image Velocimetry (PIV) and Laser Induced Fluorescence (LIF) to study the mass transfer at the air-water interface, and compared his measurements with the predictions of Schulz & Schulz (1991) employing ad hoc concentration profiles. Further, Schulz & Janzen (2009) confirmed the upper limit for the normalized RMS of the concentration fluctuations by taking into account the effect of diffusion, also evaluating the thickness of diffusive layers and the role of diffusive and turbulent transports in boundary layers. A more detailed theoretical relationship for the RMS of the concentration fluctuation showed that several different statistical profiles of turbulent mass transfer may be interrelated. Intending to present the methodology in a more organized manner, Schulz et al. (2011a) showed a way to “model” the records of velocity and mass concentration (that is, to represent them in an a priori simplified form) for a problem of mass transport at gas-liquid interfaces. The fluctuations of these variables were expressed through the so called “partition, reduction, and superposition functions”, which were defined to simplify the oscillating records. As a consequence, a finite number of basic parameters was used to express all the statistical quantities of the equations of the problem in question. The extension of this approximation to different Transport Phenomena equations is demonstrated in the present study, in which the mentioned statistical functions are derived for general scalar transport (called here “scalar-velocity interactions”). A first application for velocity fields is also shown (called here “velocity-velocity interactions”). A useful consequence of this methodology is that it allows to “close” the turbulence equations, because the number of equations is bounded by the number of basic parameters used. In this chapter we show 1) the a priori modeling (simplified representation) of the records of turbulent variables, presenting the basic definitions used in the random square wave approximation (following Schulz et al., 2011a); 2) the generation of the usual statistical quantities considering the random square wave approximation (scalar-velocity interactions); 3) the application of the methodology to a one-dimensional scalar transport problem, generating a closed set of equations easy to be solved with simple numerical resources; and 4) the extension of the study of Schulz & Johannes (2009) to velocity fields (velocity-velocity interactions). Because the method considers primarily the oscillatory records itself (a priori analysis), and not phenomenological aspects related to physical peculiarities (a posteriori analysis, like the definition of a turbulent viscosity and the use of turbulent kinetic energy and its dissipation rate), it is applicable to any phenomenon with oscillatory characteristics.

The behavior of the free surface in skimming flows along stepped chutes is investigated for the step ratio 1V:1H. Data were collected using high frequency ultrasound probes. The measurements included mean surface profiles, statistical parameters related to the surface position, aeration inception point, water depth at the inception point and transition length. The measurements were related to turbulence parameters at the free surface. The measurement methodology was adequate for both the black-water and the white-water regions. Characteristic relations are developed for different variables defined for skimming flows. The results demonstrate regions of increasing and decreasing turbulence in the transition between the black-water and the white-water flows, and a region of decay of turbulence, related to the distance needed to attain the quasi-uniform flow of the white-water.

In this study recent equations for the main geometrical characteristics of hydraulic jumps are applied to experimental data of several sources, to verify the adjustment of the equations and eventual trends observed for the adjusted parameters. The equations reflect the conservation principles of mass, momentum and energy for a hydraulic jump. They are presented in non-dimensional form, and admit ad-justment through few coefficients, defined while modelling the energy dissipation in the jump. The ad-justments highlighted here are of good quality. The adjusted coefficients are analyzed in the sense to compute the effect of roughness. It is seen that this effect may be adequately quantified and that a com-prehensive study of the coefficients is welcomed for the use of the formulation as pre-design tool for hy-draulic structures like dissipation basins. Complementing the information, the shape of the surface of the air-water mixture is also discussed, considering predictive equations, in the sense of furnishing a complete picture of the geometrical properties of hydraulic jumps. Experimental and numerical results are used.

The flow in pipes for non-Newtonian fluids is considered using a truncated series relating the shear stresses whit the radial velocity gradient. This approximation is used as an alternative way for the quantification of velocity profiles, and a lower order theoretical solution for the velocity is presented. It is observed that the calculated profiles allow approximations to pseudoplastic and to dilatant behaviors, approaching the Newtonian (parabolic) profile from the “inner side” or the “outer side”, respectively. This suggest that power series may be used to quantify aspects of non-Newtonian fluids. In the sequence, the possibility of turbulent flows in pipes was considered, and a qualitative view of the velocity profiles and the turbulent shear stresses is then presented here. This study was conducted theoretically, aiming the obtainance of solutions that allow verifying mathematical possibilities and impossibilities (such as discontinuities). The results suggest further numerical studies to evidence the possibilities of this kind of approximation.

Because the hydraulic jump is a dissipative singularity, it is used to dissipate energy for example in stilling basins downstream of spillways. On the other hand, concerns about stilling basins are the possibility of cavitation and uplift of baffle blocks, which are mainly related to pressure fluctuations, and the water depths along the hydraulic jump, relevant for the design of the walls of the stilling basins. Interestingly, pressure fluctuations and depth fluctuations are caused by the same turbulence in the roller. So, both phenomena may present similar behaviors for the statistical properties. This paper analyzes instantaneous water depth data, measured using ultrasonic sensors, for inflow Froude numbers from 2.8 to 5.3. Statistical parameters of the water depth data were obtained and compared to data of pressure fluctuations found in the literature. As ex-pected, it is shown that there are similarities between the behavior of both phenomena.

Vertical tubes are usual components of water distribution systems and of drainage systems (collecting tubes and manholes, for example). Drainage systems may be subjected to flooding events, which generate water columns with free surfaces in the vertical tubes. The water level corresponds, in these cases, to the hydraulic head where the vertical tube is located. Depending on the conditions of the flow in the system, pressure pulses may induce oscillations of the water level in the vertical tubes, eventually also generating phenomena like geysering. Oscillations may subject the buried structures to efforts not necessarily considered in the design phase. Eventual checking thus needs the periods of the oscillations. The amplitude of the oscillations may imply in spilling of water from the top section of the tube, or a momentary ejection above the outer ground level. The study of the conditions of possible spilling events is necessary to allow preventive measures. This study considers the dynamics of oscillating flows in vertical tubes. The governing equation for the flow is presented having the pressure imposed by the hydraulic head as the main impulsive factor of the movement. The resistive factors are taken into account through local and distributed losses. The equation is presented in normalized form, and predictions are compared with proper experimental data. Results obtained in adequate experimental devices, for different diameters of the vertical tube, were analyzed together. Conclusions about the different measured periods and the damping of fluctuations are presented.

The stability of humans partially immersed in risky open water flows, resulting from urban flooding caused for example by dam breaks, or failures in drainage systems, or natural extreme events, is a topic of increasing interest because it involves the human safety in an environment that is more and more subjected to extreme events of hydraulic nature. The studies in this field of the applied fluid mechanics generally present equations that handle the results through dimensional quantities. These results were generally obtained in specific experiments for the evaluation of the stability of models of the human body. Intending to advance in the direction of a more general formulation, a dimensional analysis for the problem of human stability in open flows is presented here, showing dimensionless groups that represent the mentioned problem. Equations using these nondimensional groups were then developed using statistical analyses and approximations based on principles of physics and on data of the human body. The results obtained with the proposed methodology are of very good quality, presenting high correlation coefficients and good agreement between measured and calculated data.