bluuebunny/crossref_metadata_2025 huggingface dataset:
EVALUATION OF THE APPLICABILITY OF A TURBULENT WAKE INLET BOUNDARY CONDITION
Authors: Soliman P. A. , Paula A. V. de , Petry A. P. , Möller S. V.
Published: November 2018

With the objective of reducing the computational cost of the iterative processes of aerodynamic components design, tests were carried out to study under what conditions, and with what difference, only part of the calculation domain can be solved using as input information obtained from complete simulations already solved. An experimental study of an airfoil exposed to the wake interference of an upstream airfoil at a Reynolds number of 150,000 was used to verify the solutions of the Reynolds-Averaged Navier-Stokes equations solved applying the k-ω Shear Stress Transport model for turbulence closure. A Grid Convergence Index study was performed to verify if the solution of the equations for the adopted discretization leads to results within the asymptotic range. With the physical coherence of the numerical methodology verified, comparisons between the simulations with the domain comprising the two airfoils and the domain comprising only the downstream airfoil were performed. Computational time reductions in the order of 40% are observed. The differences in the aerodynamic coefficients for the two types of simulation are presented as a function of distances non-dimensionalized by the characteristic length of the body that disturbs the flow forming the wake, showing that the difference between the two methods was inversely proportional to the distance between the two bodies. Behavior that was maintained until a point where the simulation diverges, equivalent to 25% of the characteristic length of the body that generates the wake.
VELOCITY PROFILE MODELING FOR NON-ISOTHERMAL FLOWS INSIDE A CIRCULAR TUBE
Authors: Gutierrez J. A. , Mendiburu A. A. , Ávila I. , Peréz Edgar Paz
Published: November 2018

This research proposes a new method to establish the velocity field and the dimensionless velocity profile for Newtonian and non-Newtonian flows inside a circular tube. Several studies developed regarding different fluid types (such as potency law fluid, Bingham and Herschel-Bulkley, among others) observed that a rational or irrational polynomial was used for the dependent velocity field variable. Thus, a rational polynomial was established as a starting point for this research as the dependent velocity field variable. Dimensionless velocity profiles obtained from the proposed fluid-dynamics model were experimentally compared only with dimensionless velocity profiles for non-isothermal Newtonian flows of glycerol, in cooling as well as heating. On the other hand, it was possible to calculate that RMS errors found using relative dimensionless velocity data obtained from the proposed fluid-dynamics model creates very small errors, which are comparable to RMS errors found using data obtained from application of a numerical method. Finally, the proposed fluid-dynamics model was validated with a dimensionless velocity profile obtained from the flow of a cooling process, resulting in the validity of the proposed model.
HEAT TRANSFER BETWEEN AN AUTOMOTIVE EXHAUST AND THERMOELECTRIC MODULES
Authors: Silva A. L. C.
Published: November 2018

This work aimed to study the heat transfer between an exhaust pipe of a car and thermoelectric modules. Heat transfer is the energy transport that occurs when quantities of matter that have different temperatures are placed in thermal contact and can occur in 3 different modes: conduction, convection and radiation. Thermoelectrics can convert thermal energy into electrical energy and vice versa. In this work a decision was made to install the Peltier cells in the final part of the exhaust pipe, where the temperature is lower. The temperature difference was 59°C. After calculations were found the values of the heat transfer rate: by conduction 0.164 W, by convection 0.103 and radiation 0.459.
FLAME PROFILE IN A POROUS RADIANT BURNER USING 1/2” AND 1/4” ALUMINA’S SPHERES
Authors: Campos G. P. L. , Duarte J. B. F.
Published: November 2018

Porous burners are known by their high efficiency and low polluting gases emissions. Their high efficiency is given by the great thermal radiation potential, whereas differently a normal burner, the process of combustion happens in the inner of the porous medium, which is compound by spheres of alumina, and the mix air-fuel goes through the preheating zone, potentializing the combustion. The burners are usually used in the industry, in the process of drying of paper and wood, plastic coating, food cooking and ambient heating. In this article, it was studied the behaviour of the flame in a porous radiant burner with alumina’s sphere of 1/2” and 1/4”, using LPG as fuel, compressed air as oxidizing agent and ceramic wool as thermal insulation. The burner was divided in three essential sections with a type K thermocouple in each one, which are: base, middle and top. The flame profile encountered was a floating one, however it is almost stable, presenting low variations of temperature and according to previously tests, less consuming of fuel.
ON THE MONITORING OF THE GAS-SOLID FLOWS IN INDUSTRIAL FLUIDIZED BEDS BY USING ELECTRICAL CHARGE SENSORS
Authors: Andrade M. F. F. de , Reis E. Dos
Published: November 2018

The fluidized bed technology has been used in many industrial processes. It promotes good rates of heat, mass transfer and chemical reaction by generating high level of gas-solid mixture. However, the assurance of quality and efficiency of these processes requires the monitoring of the gas-solid flow. For this propose, there are some sensing techniques that allows generating dynamic signals from cold or hot fluidized beds. They are based on pressure fluctuations, acoustic and mechanical vibrations, electrical capacitance and on electrical charges. Electrical charge sensors were proposed originally for measuring the flow velocity in pneumatic conveying. They are composed of one or more metallic electrodes that detect electrical charges in the gas-solid flow, which are generated by particle-particle and particle-wall interaction due to triboelectric effect. In this work, such sensors are explored as a robust and inexpensive solution for the monitoring of industrial fluidized beds. However, since research investments are requested specially on the design of the sensor, concerning the flow quantity of interest and the electrification processes acting on the sensor, in this work different configurations were classified from information in literature, and other were proposed in this work concerning their use with industrial fluidized beds. Although the relation between magnitude of the detected charges and some physical quantities of the flow, such as concentration, is still not clear, other important information can be obtained by analyzing dynamic signals, as velocity or bubbles frequency, or even for identifying of the fluidization regime. It was stated that each configuration, with its own shape and arrangement, can promote or not one or other electrification process by contact, friction or induction and, therefore, each one has a different perception of the flow.
FUEL CELL: FEASIBILITY ANALYSIS OF ITS APPLICATION IN AUTOMOBILES
Authors: Gontijo R. M. , Silva L. M. , Pereira A. R.
Published: November 2018

The need to reduce the emission of harmful gases into human life, together with the dependence on oil as a primary source of fuel for internal combustion engines (ICE), are part of the current global scenario. This scenario opens space for fuel cells (FC), technology that generates electricity as the main product of oxide-reduction reactions between Hydrogen and Oxygen. An efficient and clean alternative that appears as a possibility for the substitution of ICE. The present article proposes a model of FC and compares it technically with a conventional ICE, in order to prove the efficiency, performance and environmental impact feasibility of the use of this technology in commercial vehicles.
EXPERIMENTAL ANALYSIS OF A SCREEN-COVERED GROOVE HEAT PIPE
Authors: Krambeck L. , Bartmeyer G. A. , Santos P. H. D. , Alves T. Antonini
Published: November 2018

In this research, a heat pipe with screen-covered groove capillary structure was experimentally analyzed. The heat pipe was manufactured from a copper tube with the external diameter of 9.45mm, inner diameter of      6.20mm, and a total length of 200mm. A Wire Electrical Discharge Machining, or Wire-EDM, was used to manufacture axial microgrooves in the heat pipe. A layer of phosphor bronze mesh #100 completed the capillary structure. Distilled water was the working fluid and the loading filling ratio was 60% of the evaporator volume. The condenser was cooled by air forced convection, the adiabatic section was insulated with fiberglass, and the evaporator was heated by an electrical resistor and it was insulated from the environment with aeronautic insulation. The heat pipe was tested in horizontal position, under different heat loads varying from 5 up to 30W. The experimental results showed that the screen-covered groove worked satisfactorily as a capillary structure.
EFFECTS OF TURBULENCE-RADIATION INTERACTIONS IN A NON-PREMIXED TURBULENT METHANE-AIR FLAME
Authors: Lemos L. D. , Centeno F. R. , França F. H. R.
Published: November 2018

This work studied a turbulent flame and analyzed the interaction between turbulence and radiation (TRI). The problem consists of a non-premixed turbulent methane flame surrounded by a low-velocity air coflow identified as Flame DLR-A. The steady laminar diffusion flamelet (SLDF) model is used to solve the chemical kinetics. To generate the flamelet library, turbulence-chemistry interaction is taken into account through previously assumed probability density functions (PDF) of mean scalars. Radiative heat flux is calculated with the discrete ordinates method, considering the Gray Gas model (GG). Turbulence is solved with k-ε Standard model and TRI methodology is based on temperature self-correlation. The solution is obtained using ANSYS/Fluent code coupled with user-defined functions (UDFs). Results indicated that the temperature and chemical species predictions are little affected by TRI, while the radiative quantities (radiative heat flux on the domain wall) are importantly affect by TRI effects.
ANALYSIS OF HEAT TRANSFER IN STEEL BILLETS DURING TRANSPORT
Authors: Cançado K. N. , Machado L. , Soares L. N.
Published: November 2018

During the seamless steel tubes manufacturing process, the temperature decrease between the exit of the furnace and the rolling mill entrance is determinant factor in the rolling process and the quality of the tube. This study aims to model the cooling of the billets during transport in order to evaluate the minimum temperature required for the billet leaves the furnace and also the maximum transport time without compromising the rolling process, allowing a better setup of equipment and reducing the production costs. The cooling profile was determined numerically through energy balances performed on the billet and the results obtained were compared with real values of temperature measurements by thermocouples installed on the billet. Measurements with thermocouples were conducted in billets of 270, 230 and 180 mm diameter. The error relative to the real values for all cases was below than 2.5% and the model is considered validated to use.
NUMERICAL SIMULATION OF A ELASTO-VISCOPLASTIC FLUID FLOW INSIDE A CAVITY
Authors: Furtado G. M. , Frey S. , Naccache M. F. , Mendes P. R. de Souza
Published: November 2018

This article addresses finite element approximations for elasto-viscoplastic flows. Numerical simulations aiming at investigating the role of elasticity for inertialess flows of viscoplastic materials within lid-driven cavity.The mechanical model is made up of the usual governing equations for incompressible fluids coupled with a Oldroyd-B type equation (de Souza Mendes, 2011) modified to incorporate the dependency both of relaxation and retardation time as the viscoplastic viscosity on the strain rate. These parameters depend on the material microstructure, which level is described by an structure parameter . This model is approximated by a multi-field Galerkin least-squares formulation (Behr et al., 1993) in terms of extra-stress tensor, the pressure field and the velocity vector. Results, focused on the determination of yield surface topology, investigate the influence of elastic and viscous governing parameters on the flow pattern.
ENGENHARIA E PESQUISA COLABORATIVA ENTRE INDÚSTRIA E ACADEMIA
Authors: Prata Alvaro T. , Ferreira Rogério T. S. , Melo Cláudio
Published: November 2018

O Exercício da Engenharia no ambiente acadêmico está longe de ser considerado satisfatório quando se analiza a prática corrente adotada nas universidades brasileiras. Tanto na realização de serviços técnicos como no exercício de atividades de pesquisa, a forma de atuaçãodo professor não contribui para que melhore seu desempenho como engenheiro. Na realização de serviços técnicos é comurn o professor desempenhar funções corriqueiras e desperdiçar o seu tempo com atividades menos nobres e mais condizentes com sua qualificação profissional. Na pesquisa é comum o professor assumir uma posição por demais abstrata, distante da realidade tecnológica praticada no setor industrial. Ao ensinar, o papel de educador fica prejudicado pela falta de conhecimento prático e pelo não envolvimento com a realidade da profissão. É pois, de fundamental importancia que o convívio com o setor industrial esteja presente na vida do engenheiro professor.Adicionalmente, nao há hoje uma política científica e tecnológica nacionalista e a onda globalizante tern sido extremamente prejudicial para nossa capacitação tecnológica, criando uma dificuldade adicional ao exercício pleno da engenharia. Neste cenário, a responsabilidade da indústria e da academia em estabelecer relações profissionais que favoreçam nosso desenvolvimento tecnológico nao pode ser minimizada.
CONSTRUCTAL THEORY: FROM ENGINEERING DESIGN TO PREDICTING SHAPE AND STRUCTURE IN NATURE
Authors: Bejan Adrian
Published: November 2018

This is a review of two new and important developments in thermal science. First, there exist fundamental optima in the constitution and operation of flow (nonequilibrium) systems, man-made and natural. These optima can be identified based on the simplest models that still retain the essential features of the real systems. Examples are the spatial allocation of heat transfer area in a power plant, and the temporal optimization of on & off processes. The second development is that the engineering method of modeling and optimization has been extended to natural systems, animate and inanimate (e.g., tree networks). This step has been named constructal theory for the reasons given in Section 3. The objective of such work is to predict the macroscopic spatial and temporal structure (organization) that is everywhere. It is to inject a dose of determinsm (theory) in a field that until recently considered natural structures to be nondeterministic: results of chance and necessity. These developments bring to mind the advice left to us by J. W. Gibbs more than one hundred years ago:
"One of the principal objects of theoretical research in any department of knowledge
is to find the point of view from which the subject appears in its greatest simplicity."
APLICAÇÃO DE FERRAMENTAS NUMÉRICAS NO PROJETO DE COMPRESSORES PARA REFRIGERAÇÃO
Authors: Fagotti Fabian , Puff Rinaldo
Published: November 2018

O projeto ótimo de compressores requer análises em diversos campos de comnhecimento, além de ser restrito por várias condições de contorno não necessariamente relacionadas ao ótimo de componentes isolados. O uso de programas de simulação tem mostrado ser uma ferramenta de projeto extremamente útil, tanto no teste de hipóteses prévio à construção de protótipos, a qual demanda muito tempo e tem alto custo. Este artigo descreve programas de simulação e abordagens teórico-experimentais usadas na Embraco para o projeto de compressores herméticos alternativos de refrigeração. Mais especificamente, o escopo se restringe à problemas de escoamento e transferência de calor, bem como alguns tópicos correlatos, em especial questões ligadas a ruído, projeto de motores e ao sistema de refrigeração em si.
CÁLCULO DA CURVA DE PERDA DE CARGA DOS CIRCUITOS AXIAIS INTERNOS DE REFRIGERAÇÃO DE MÁQUINAS ELÉTRICAS GIRANTES
Authors: Silva Hilton Penha
Published: November 2018

Tendo como objetivo o cálculo e otimização da refrigeração das máquinas elétricas girantes de grandes potências, figura 1, foi desenvolvido um método de cálculo da curva de perda de carga dos circuitos axiais de ventilação. Esse método pressupõe a representação do circuito de ventilação de uma forma semelhante a dos circuitos elétricos.
A maior dificuladade da solução do circuito está no fato de que as resistências de perda de carga, são funções não lineares e, as equações que relacionam as pressões com vazões são também não lineares.
O método desenvolvido baseia-se na associação das curvas das resitências de perda da carga, de tal forma que, uma vez obtida a curva de resistência de perda de carga total de circuito, o ponto de operação do ventilador pode ser facilmente obtido e conseqüentemente as vazões individuais em cada trecho do circuito.
SIMULACIÓN NUMÉRICA DEL PROCESO DE SECADO
Authors: Abalone R. , Gastón A. , Lara M. A.
Published: November 2018

En el presente trabajo se estudia el proceso de secado de un producto anisotrópico (batata) por medio de las ecuaciones de Luikov. Estas ecuaciones de transferencia de calor y materia se resuelven aplicando dos técnicas numéricas diferentes. En la primera, mediante una transformación de las ecuaciones diferenciales se obtiene la evolución temporal de la temperatura media y del contenido global de humedad del producto. En la segunda se resuelve el mismo sistema aplicando el método de elementos finitos. A partir de los valores nodales de temperatura y contenido de humedad se obtienen valores medios que se comparan con los obtenidos por el primer método.
Estos modelos fueron utilizados para la determinación de los valores de algunos parámetros característicos del proceso de secado, a partir del ajuste de los resultados numéricos con datos experimentales.
Se obtuvieron las difusividades másicas en las direcciones normal y paralela a la fibra de la batata y los coeficientes de transferencia de calor y de masa.
PISTON LUBRICATION IN RECIPROCATING COMPRESSORS
Authors: Prata A. T. , Fernandes J. R. S. , Fagotti F.
Published: November 2018

Piston dynamics plays a fundamental role in two critical processes related to fluid flow in reciprocating compressors. The first is the refrigerant leakage through the radial clearance, which may cause considerable loss in the pumping efficiency of the compressor. The second process is the viscous friction associated with the lubricant film in the radial clearance; certainly a significant factor in the compressor energy consumption. In the present contribution a numerical simulation of the piston movement inside the cylinder of a reciprocating compressor is performed. The compressor considered here is a small hermetic compressor employed in domestic refrigerators. For the problem formulation both the axial and the radial piston motion is considered. In operation, the piston moves up and down along the axis of the cylinder, but the radial oscillatory motion in the cylinder bore, despite being usually small, plays a very important role on the compressor performance and reliability. The compromise between sealing of the gas leakage through the piston-cylinder clearance and the friction losses requires a detailed analysis of the oscillatory motion for a good design. The forces acting on the piston are the hydrodynamic force due to the pressure build up in the oil film (lubrication effects), the force due to the connecting rod, the viscous force associated with the relative motion between the piston and oil, and the force exerted by the gas on the top of the piston. All corresponding moments are also included in the problem formulation of the piston dynamics, in order to determine the piston trajectory, velocity and acceleration at each time step. The hydrodynamic force is obtained from the integration of the pressure distribution on the piston skirt, which, in turn, is determined from a finite volume solution of the time dependent equation that governs the oil flow. A Newton-Raphson procedure was employed in solving the equations of the piston dynamics. The results explored the effects of some design parameters and operating conditions on the stability of the piston, its sealing performance and friction losses. Emphasis was placed on investigating the influence of the pin location, radial clearance and oil viscosity on the piston dynamics. The complexity of the piston movement in reciprocating compressors was demonstrated and the detailed model presented can be employed as an useful tool for engineering design.
EDITORIAL
Authors: Vargas J. V. C.
Published: November 2018

The first number of Thermal Engineering marks the fulfillment of a long term aspiration for the thermal science community in Brazil.The country has had a steady and solid industrial growth since the 1940's, reaching a development level which is comparable to the most developed countries in the world.However,the scientific and industrial communities have not interacted enough during this evolution process, mainly due to the lack of effective media between them.The purpose of this new journal is to become a publication "locus" where the scientific and industrial communities can interact technically.An applied section has been designed to comprise articles that document modern engineering applications, or general advances in industry. A scientific section was also created to publish articles that deal with fundamental advances in heat transfer and fluid mechanics, new physical insights, and novel experimental and analytical methods that have great appeal for the industry community. This way, the journal intends to explore problems and situations that are relevant to industrial engineer and academic professionals.Clearly, the articles will attract the interest of both communities, and will contribute to the establishment of a better link between the industry and the university.The institutional support from the Brazilian Society of Mechanical Sciences (ABCM), that for the past twenty five years has been unique in promoting the mechanical sciences in our country, and from the Brazilian Society of Industrial Machinery and Equipments (ABIMAQ), that for the last sixty years is engaged with our technological development, strengthens our belief in the complete success of this enterprise.This first issue brings together several articles from internationally recognized scientists in the scientific section, and several selected articles from the industry in the applied section. For the next numbers we welcome technical articles from both communities to either section.We also welcome response and comments from our readers which will eventually help the success of RETERM.
EVALUATION OF SOLIDS CARRYING CAPACITY IN AERATED FLUID DRILLING: REAL SCALE TESTS AND MODELING
Authors: Martins A. L. , Lourenço A. M. F. , Andrade Jr. P. H. , Silva Jr. V. , Silva P. R. C. , Nakagawa E. Y.
Published: November 2018

This paper summarizes the results of two sets of experimental tests performed at PETROBRAS real scale test facility aiming the evaluation of solids return times in aerated fluid drilling. The effect of the following parameters was studied: liquid and gas injection rates, particle diameter and depth. Results indicate that the gas has a major effect in accelerating the liquid phase, which would be responsible for carrying the particles to the surface. The concept of effective liquid velocity coupled with an adequate procedure for particle sedimentation velocity calculation reproduced the experimental results adequately.
CONJUGATE MIXED CONVECTION IN AIR-COOLED HEAT SINKS USING A NON-BOUSSINESQ APPROACH
Authors: DeAndrade C. R. , Pantaleão A. V. , Zaparoli E. L.
Published: November 2018

This work reports a numerical study of the mixed convection in finned duct flow that occurs in heat sinks devices. The laminar flow is considered fully developed and the convection-conduction coupling is treated by a conjugated approach. The mathematical formulation of this problem is constituted by the mass, momentum and energy equations. The partial differential equations system is solved by the Galerkin finite element method, adopting a pressure Poisson equation to establish the pressure-velocity coupling and to obtain a mass conserving flow. The results using the classical Boussinesq approximation (density varies linearly with the temperature in the buoyancy-term) are compared with the non-Boussinesq approach (density variation in all terms of the governing equations) showing that both the heat transfer and friction factor are affected by the new considerations. The duct aspect ratio and the solid to fluid thermal conductivity ratio influences on the heat transfer rate are also analyzed. This analysis tool was also shown appropriate for the optimization of electronic components air-cooled heat sinks.
THERMAL CONDITIONING USING PHASE CHANGE MATERIALS
Authors: Boucíguez A. , Villa L. T. , Lara M. A.
Published: November 2018

A combined procedure using a classical qualitative result for initial and boundary problems associated to parabolic equations, numerical treatment and computational simulation, have been used to obtain some results on the dynamic behavior of the function that provides the position of the melting interface or moving front of the phase change material at each time. This material is used in a special device that is designed in order to get thermal conditioning in physical - chemical systems of practical importance. A monotone dependence of the melting interface upon some parameters is also shown.
PETROLEUM, SAFETY AND ENVIROMENT
Authors: Chote F. R. , Kaskantzis G. N.
Published: November 2018

ABSTRACTThe Risks Analysis consists of the systematic exam of an industrial installation (project or existent) to identify the present risks in the system and to form opinion about potentially dangerous occurrences and its possible consequences. There are two types of risks analysis: the qualitative analysis and the quantitative. The qualitative analysis studies all the possible existent risks of the place, and it relates these risks in agreement with the probability of such accidents happen and with the coming consequences of such accidents. The risks that present high probability of happening and that cause great damages to the structure or the people are analyzed, then, in a quantitative way.Two sceneries were specified for the use of quantitative techniques. The studied sceneries are related with the existent risks in the storage of gasoline in drums stored in the Laboratory of Analysis of Fuels of UFPR / ANP. The models associated to the sceneries in studies were obtained of the literature. The studied sceneries were Fire on pools and Unconfined Explosion. For each studied scenery it was possible to evaluate the consequences of material, humans and environmental damages associated to the accidents. The results show that in case of the fire in pool, for a distance of 61.35 m and 42.8 m starting from the center of the flame, burns happen in third degree and first degree, respectively, in people that are not protected and, for the unconfined explosion the results show that for a distance of 15.43 m of the center of the explosion a person has 90% of chance of having tympanum rupture, and for a distance of 9.5 m of the center of the explosion a person has 99% of chance of dying.
HOT WIRE METHOD FOR THE THERMAL CHARACTERIZATION OF MATERIALS: INVERSE PROBLEM APPLICATION
Authors: André S. , Rémy B. , Pereira F. R. , Cella N. , Silva Neto A. J.
Published: November 2018

An experimental set-up of the hot wire method is presented. The present design
allows the measurement of the temperatures at two different points on the heating
wire with an acquisition system that performs measurements at a frequency of 1kHz
with a 12 bit numerical converter. An analytical solution for the direct model for the
time dependent problem of heat transfer is employed. It is based on the quadrupole
method which basically consists in a transfer matrix approach which is possible
through the use of Laplace transforms. It extends the electrical analogy of heat
transfer problems using the notion of impedance, and allows to take into account the
thermal behavior of the wire, as well as contact resistance and heat loss effects in a
very simple straightforward way. In the identification process carried on the
temperature experimental data relies on a sampling of the data that is
logarithmically spaced in time. The initial guesses for the thermal conductivity
values are obtained applying the well known and ideal model of the linear
temperature evolution versus the logarithm of the time. These values are used to
start up the algorithms that are applied in the minimization of the cost functional of
the squared residues between measured and calculated temperatures. The precision
of the estimates is assessed with the calculated confidence bounds obtained by the
variance-covariance matrix at the converged solution.
SUBSTITUTION OF NTO BY HTP IN A BIPROPELLANT RCS
Authors: Oliveira U. C. , Villas Bôas D. J. F.
Published: November 2018

The present article presents some theoretical considerations about the implications
due the change of the oxidizer in a bipropellant propulsion system. Preliminary
analysis conducted on the NTO/UDMH 400 N engine of a roll control system shows
that this engine could be capable of operation with HTP90 without significant
modification in the design. The new propellant combination is less toxic, can be
handled more easily, has a wider operational temperature range, and yields a more
amenable thermal environment from the combustion down to the exhaustion. Even
with a decrease in liquid film cooling, the HTP90/UDMH engine would present a
satisfactory reduction of the combustion chamber temperature and approximately the
same performance level of the original NTO/UDMH engine.
EDITORIAL
Authors: Vargas J. V. C.
Published: November 2018

RETERM – Thermal Engineering is an official publication of the Brazilian Society of Mechanical Sciences (ABCM). In this fourth issue, the journal continues to be divided in two main sections: science and technology. The former is directed to publish complete articles that deal with fundamental advances in heat transfer and fluid mechanics, new physical insights, and novel experimental and analytical methods that have great appeal for the industry community, and the latter is designed to comprise informative articles that document modern engineering applications, or general advances in industry.In this issue, we continue to publish the best articles written in English language, presented at the 9th Brazilian Congress of Thermal Engineering and Sciences, ENCIT 2002, held in Caxambu, MG, from October 15th to 18th, 2002, that were selected by the Associate Technical Editors of RETERM, according to the scientific criteria of the journal. The idea is to increase the industrial and scientific impact of the research results presented in the Congress. Additional articles that have been submitted and reviewed in the regular RETERM publication process are also included in the current issue.The institutional support from the Brazilian Society of Industrial Machinery and Equipments (ABIMAQ), continues to strengthen our belief in the success of this enterprise. To open a perspective to the maintainance and continuity of RETERM, we invite the readers from the industrial community to contact our staff for subscriptions and publicity in RETERM. For the next issues we continue to welcome technical articles from both the scientific and the industrial communities to either section of RETERM, contributions to the other sections of the journal, and suggestions for new sections as well. We also welcome response and comments from our readers that will certainly help the success of RETERM.
BLUFF-BODIES VORTEX SHEDDING SUPRESSION BY DIRECT NUMERICAL SIMULATION
Authors: Ribeiro P. A. R. , Schettini E. B. C. , Silvestrini J. H.
Published: November 2018

Vortex shedding is responsible for harmful vibrations on immersed
structures and for increasing their drag coefficients. Thus vortex shedding
suppression is highly interesting in order of decrease maintenance costs of
standing structures and fuel costs on moving ones. Vortex shedding
suppression is here achieved with the use of splitter plates by means of
numerical simulations at a low Reynolds range, Re 100 and 160. For this
purpose it has been used a high order finite difference method in association
with a virtual boundary method, responsible for the obstacles
representation. The use of this novel numerical method showed a great
concordance with experimental results by means of low computational
costs.
ANALYSIS OF INTERFACIAL AND MASS TRANSFER EFFECTS ON FORCED CONVECTION IN GAS-LIQUID ANNULAR TWO-PHASE FLOW
Authors: Nogueira E. , Dantas B. D. , Cotta R. M.
Published: November 2018

In a gas-liquid annular two-phase flow one of the main factors influencing
the determination of heat transfer rates is the average thickness of the liquid
film. A model to accurately represent the heat transfer in such situations has
to be able of determining the average liquid film thickness to within a
reasonable accuracy. A typical physical aspect in gas-liquid annular flows is
the appearance of interface waves, which affect heat, mass and momentum
transfers. Existing models implicitly consider the wave effects in the
momentum transfer by an empirical correlation for the interfacial friction
factor. However, this procedure does not point out the difference between
interface waves and the natural turbulent effects of the system. In the
present work, the wave and mass transfer effects in the theoretical
estimation of average liquid film thickness are analyzed, in comparison to a
model that does not explicitly include these effects, as applied to the
prediction of heat transfer rates in a thermally developing flow situation.
DESIGN AND DEVELOPMENT OF A 70 N THRUST CLASS TURBOJET ENGINE
Authors: Trazzi P. E.
Published: November 2018

Small turbojet engines are being used for propulsion of radio-controlled
model airplanes. The design and development of the model 505 small jet
engine are reviewed. Small size gas turbines present special design and
construction difficulties, some of which are addressed; design choices
leading to the final configuration are discussed. Aero-thermodynamic
aspects are covered along with experimental data when available. The unit
is comprised of a radial compressor, an annular combustion chamber, and
an axial turbine plus accessories; details on these components and on
production aspects are presented.
EXPERIMENTAL VALIDATION OF A CAPPILARY TUBE SIMULATION MODEL WITH REFRIGERANT MIXTURES FLOW
Authors: Fiorelli F. A. S. , Silvares O. M.
Published: November 2018

This paper presents the experimental validation of a simulation model for
refrigerant mixtures flow through capillary tubes. To perform such
validation it was built an experimental apparatus using a blow-down
process. It was carried out preliminary tests for characterization of
experimental parameters: actual capillary tube diameters; relative
roughness; and the heat losses in subcooling/quality control system. It
was obtained almost 200 experimental points for R-407C (a zeotropic
mixture) and R-410A (a near azeotropic mixture). Complete data set for
each point consists of the measured pressure and temperature profiles,
mass flow rate and mixture composition, as well as subcooling/quality
control system inlet and outlet temperatures and heater electric power
consumption for tests with two-phase flow capillary tube inlet conditions.
Comparison of simulation and experimental data show a good agreement.
Main deviations are connected with the delay of vaporization
phenomenon occurrence, experimentally verified by the authors.
MIXED GAS-OIL SUBSEA PIPELINES IN OFFSHORE TECHNOLOGY: TECHNICAL AND ECONOMIC ASPECTS
Authors: Caputo A. C. , Pelagagge P. M. , Ponticiello I.
Published: November 2018

The choice of gas separation and transportation mode in offshore
applications may significantly affect the project profitability. Main
alternatives are separation on board the platform with the utilization of
separate subsea pipeline for single-phase gas and oil transportation, and
remote separation with multiphase transportation of the gas-oil mixture in a
single pipeline. In order to assist the project engineers during the feasibility
study phase, the problems relevant technical and economic issues are
analysed in this paper after preliminarily describing the two process
schemes. In particular a computer model is developed in order to simulate
the two-phase flow of the multi-component mixture adopting the Beggs and
Brill model, which showed to be the most reliable approach in this
application. A cost comparison with reference to a hypothetical but realistic
case study is finally carried out to assess the convenience of the multiphase
flow solution. This option appears to be especially attractive when multiplewell
fields exist which can be developed in an integrated manner by
providing a single centralized separation plant.
A Allowance for additional mass (t)
L Liquid production (m3/day x 1000)
STP Standard Temperature and Pressure
EXPERIMENTAL ANALYSIS OF A HEAT PUMP ASSISTED RECUPERATIVE AIR DEHUMIDIFIER
Authors: Pereira C. A. B. , Pereira R. H. , Marques R. P. , Parise J. A. R. , Sodré J.R.
Published: November 2018

This paper describes the experimental analysis of a heat pump assisted recuperative
air dehumidifier. The system consisted of an air-to-air vapor
compression heat pump, coupled to the air ducting. Dehumidification was
generated by reduction of the air temperature through the evaporator below
the dew point, and thus promoting the condensation of the water vapor.
Moist air was then warmed up in the condenser, resulting in a lowtemperature
low-humidity air stream. Low energy consumption values are
achieved in such systems as the latent heat of the water vapor acts as the
heat pump own heat source. Occasionally, the compressor heat is also recoverable.
The innovative feature of the present analysis was the introduction
of an air-to-air plate recuperator, to further promote dehumidification,
yet at the expense of greater compressor energy consumption. An experimental
apparatus was constructed to perform comparative tests of the dehumidifier
operating with and without the recuperator. A closed air circuit
was employed, with the air mass flow rate as the controlling parameter of
the experiment. Tests were also carried out with an open circuit.
Fuzzy clustering algorithm to identify the effects of some soil parameters on mechanical aspects of soil and wheat yield
Authors: Servadio Pieranna , Verotti Matteo
Published: November 2018

In this paper, site-specific management zones (MZs) were delineated in three fields belonging to a farm in the center of Italy and characterized by different soil texture. Crop yield and various soil parameters, both physical (soil structural stability, clay fraction, water content, and organic matter) and mechanical (shear strength and penetration resistance) were monitored. Yield data were acquired by means of a combine harvester equipped with a precision land management system during three consecutive growing seasons. At the end of the third growing season, soil properties were investigated by means of georeferenced soil sampling. After data gathering, a fuzzy clustering algorithm was applied to define management zones. Results highlighted spatial variability between the three fields and temporal variability between the three consecutive growing seasons. Whilst the latter could be ascribed to the rainfall distribution (therefore moisture could be considered as a limiting factor in wheat growth), the delineated MZs suggest that clay content and organic matter could affect both mechanical parameters of soil and crop yield. The defined MZs can serve as a basis to generate prescription maps for variable-rate application inputs and variable tillage.
Short communication: Identification and relationship of the autochthonous ‘Romé’ and ‘Rome Tinto’ grapevine cultivars
Authors: Jiménez-Cantizano Ana , Amores-Arrocha Antonio , Gutiérrez-Escobar Rocío , Palacios Víctor
Published: November 2018

The ‘Romé’ variety is considered an Andalusian (southern region in Spain) autochthonous black grape cultivar. However, several white and black grapevine accessions are known by this name, according to Vitis International Variety Catalogue. The aim of the present work was to clarify the identity of the ‘Romé’ and ‘Rome Tinto’ as black grapevine cultivar. Eight accessions known as ‘Romé’ and two as ‘Rome Tinto’ were analyzed using 30 OIV descriptors and 22 SSR loci. The morphologic and genetic analysis showed that all accessions studied presented the same genotype and phenotype and grouped with South Spanish cultivars. This study helps to clarify the confusion over the identity of ‘Romé’ grapevine cultivar, and provides a solid basis to develop a germplasm collection to protect grapevine diversity and to recover cultivars that may be in danger of extinction.
RELAKSACJA BELEK Z PŁYT WIÓROWYCH – ANALIZA WYNIKÓW BADAŃ ROZPOZNAWCZYCH
Authors: Socha Tomasz , Kula Krzysztof
Published: November 2018

W referacie przedstawiono wyniki badań eksperymentalnych oraz analizę teoretyczną zjawiska relaksacji belek z płyt wiórowych. Do matematycznego modelowania reologii badanego materiału wykorzystano trzy liniowo lepkosprężyste modele reologiczne. Analizując uzyskane wyniki stwierdzono, iż reologiczne zachowanie belki najlepiej opisuje model pięcioparametrowy, złożony z szeregowo połączonych modeli standardowego i Kelvina-Voigta.
ANALIZA POWIĄZAŃ STRUKTURALNYCH DZIELNICY NOWE MIASTO W ZIELONEJ GÓRZE
Authors: Andrzejewska Ewelina , Bazan-Krzywoszańska Anna , Skiba Marta , Stępkowska Ewelina
Published: November 2018

W artykule przedstawiono strukturalną analizę uwarunkowań pod względem liczby mieszkańców i ich dostępu do podstawowych usług. Analizą objęto część miasta (Dzielnica Nowe Miasto) włączonego z dniem 1 stycznia 2015 roku do obszaru administracyjnego gminy Zielona Góra i potencjalne możliwości rozwoju efektywności miejskiej. W artykule wzajemne powiązania w systemie miejskim, opisano jako przepływy związane z alokacją ludzi, przyjmując że struktura systemu zawiera w sobie rozłożenie przestrzenne elementów, sposób ich stałych powiazań i zmienne się w czasie interakcje między nimi.
NAWIERZCHNIA Z BETONU WAŁOWANEGO JAKO ALTERNATYWA DLA DRÓG LOKALNYCH
Authors: Radwański Wojciech , Pytlowany Tomasz
Published: November 2018

W pracy przedstawiono podstawowe zasady projektowania składu mieszanki betonowej i omówiono technologię wykonywania nawierzchni z betonu wałowanego. Przedstawiono z sukcesem zrealizowany odcinek lokalnej drogi w technologii betonu wałowanego na ulicy Wisze w Krośnie. Wykonano analizę niezawodnościową dla nawierzchni betonowej oraz asfaltowej w odniesieniu do projektowanego okresu eksploatacji.Do analiz porównawczych przyjęto system szeregowy oraz równoległy warstw nawierzchni.
ZREKULTYWOWANE SKŁADOWISKO ODPADÓW KOMUNALNYCH JAKO POTENCJALNE ŹRÓDŁO METALI CIĘŻKICH W GLEBACH
Authors: Rolka Elżbieta , Berk Paulina , Kosiorek Milena , Żołnowski Andrzej C. , Klach-Chęcmanowska Magdalena
Published: November 2018

Celem pracy była ocena oddziaływania zrekultywowanego składowiska odpadów komunalnych w gm. Dywity (woj. warmińsko-mazurskie) na występowanie w glebach metali ciężkich. W ramach podjętych badań z czaszy składowiska i jego okolic pobrano 16 prób gleby. Próby pobierano zgodnie z kierunkami stron świata w odległości 5, 10 i 15 m od czaszy lub rowu opaskowego. W trakcie analiz laboratoryjnych oznaczono zawartość wybranych metali ciężkich (Fe, Cu, Zn, Mn, Pb, Cr, Ni, Co i Cd), zarówno ich form całkowitych i przyswajalnych. Uzyskane wyniki wska-zują na duże zróżnicowanie zawartości pierwiastków w analizowanej glebie, co było zależne od badanego metalu jak również od lokalizacji miejsca poboru i odległości od składowiska. Największą koncentrację większości oznaczonych metali ciężkich wykazano w glebie pobranej po północnej stronie składowiska, zlokalizowanej przy wjeździe na teren badanego obiektu. Wykazano liczne ujemne zależności między zawartością metali ciężkich a wzrastającą odległością od składowiska. Pomimo tych obserwacji nie stwierdzono przekroczenia przyjętych norm (Dz. U. 2016 r. poz. 1395) w zakresie zanieczyszczenia gleby analizowanymi pierwiastkami śladowymi.
Praca wychowawcza wśród Ukraińców w Wojsku Polskim w latach 1921–1939
Authors: Mraka Ihor
Published: November 2018

The spread of mandatory military service for all citizens in II Rzeczypospolita caused the rapid growth of representatives of national minority in the army, Ukrainians in particular, who were often indifferent or sometimes even hostile to the country. One of the main reasons for indifference or hostile from Ukrainians was the events of Polish-Ukrainian war 1918–1919, the fight for Lviv, the defeat of ZUNR (West Ukrainian People’s Republic), in which Poland was considered to be guilty. At the same time the level of national and civil consciousness of many Poles was low enough. Taking all that into consideration, military and political authorities realized the necessity of organizing some educational activities for recruits. In the army there were some regular educational lectures with tendentiously chosen historical examples, whose aim was to smooth tensions in bilateral relations, to integrate Ukrainians into society, to bring up the sense of patriotism to Motherland, country of residence and finally to assimilate. To reach this aim, excursions, theatres and cinemas were also used for this reason.
Dramaturgia Maksyma Gorkiego w Polsce
Authors: Krycka-Michnowska Iwona
Published: November 2018

Maxim Gorky’s person has become a legend already during the writer’s life, and his perception has been ideologized both in Russia and abroad. This is evidenced by the analysis carried out in the article reception Gorky’s drama in Poland, the most important phase of which was determined by the changing political situation. The reception has changed substantially: from the spontaneous popularity of the Russian writer at the turn of the 19th and 20th centuries through ambivalence in the interwar period, forced apotheosis after World War II to marginalization after 1989 and reinterpretation attempts in recent times. As the analysis shows, a significant part of Gorky’s plays has survived the difficult test of time. These literary works, for many directors and spectators, are a carrier of universal values, while the author is considered a classic of Russian dramaturgy.
Określenia dodatkowe szlachty z sufiksem -ski w starostwie grabowieckim w XVI wieku
Authors: Olejnik Marek
Published: November 2018

The 16th century additional appellation (OD) of gentry in starosty district of
Grabowiec have been analyzed in the article. The source database used in the article
contains the municipal books of Grabowiec from 16th century. On the base of
analyzed material it can be concluded that gentry antroponyms with suffix -ski have
two-piece form (name and surname). Analytical forms applied in gentry naming are
addition which had a task to differentiate individual units of expanding gentry
families. In the presented material prepositional phrases appear next to synthetic
terms.