Marcelo Errera

Universidade Federal do Paraná | UFPR · Department of Environmental Engineering

This work shows an analysis of the construction of the geometric arrangement of blocks mounted on the surfaces of a channel subject to a laminar, incompressible flow, with forced convection in a two-dimensional domain. The construction is carried out through a construction function based on the system performance indicator, i.e., the heat transfer...

Resumo. Este trabalho mostra uma análise da construção do arranjo geométrico de blocos montados nas superfícies de um canal sujeita a um escoamento laminar, incompressível, com convecção forçada em um domínio bidimensional. A construção é realizada através de uma função de construção baseada no indicador de performance do sistema, ou seja, a taxa d...

The role of evolutionary mechanisms, identified in Nature and adapted in Engineering, is reviewed in the genesis of Architecture.

Otto cycle vehicles with gasoline direct injection (GDI) can reduce fuel consumption by 5–20%. In compliance with current legislation in Brazil, this technology was introduced to the domestic market in the form of a first flex-fuel GDI vehicle in 2013. However, despite gains in efficiency, studies in the literature have shown that GDI engines tend...

There is consensus that the use of renewable energy must be expanded. More and more restrictions on the use of fossil derived fuels may open the way for an increased consumption of biomass event those so far not perceived as feasible, such some biomass residue. Energy derived from biomass residues may provide even more benefits because it may repla...

This article shows that the sudden end of economic expansion (movement, wealth) emerges as a natural, physical feature of the spreading movement, which has access to power (money), freedom to morph, and power storage (savings) for future movement on even greater areas. The movement is driven by power generation, which is interspaced with power savi...

The Brazilian legislation does not establish limits or methodology for the measurement of aldehydes in the exhaust of heavy diesel engines. No conclusive studies on aldehyde emissions by such engines have been found in the literature available. This work measured the aldehyde emissions from a P7 diesel cycle engine (EURO V), which was tested on an...

This work presents a network analysis of the scientific publications, co-authorship and citations, for the Brazilian community, associated to the word "constructal" that appears in Journals between the years 1996 to December of 2018, using the search engine recognized in the international academic community (Scopus). The constructal network consid...

This work presents a network analysis of the scientific publications, co-authorship and citations associated with the word "constructal" that appear in journals between the years 1996 to 12/2018 using a search engine recognized in the international academic community (Scopus). The constructed network considers the existing relationships between aut...

A comb-like network has a single manifold duct, which ramifies to several branches, all subject to a pressure reservoir. Applications for such networks include vascular systems such as microchannel heatsinks, in which a working fluid needs to be fed to a great number of small volume elements. A configuration with constant branches of diameter and s...

Urban air quality is directly associated to vehicle emissions. Although technology of fuel, engines and abatement have improved, the incessant increase of the size of the urban fleet promotes further increase in the pollutants by two reasons: more sources and degenerated circulating conditions. In this work, the impacts of different scenarios of P...

Present numerical work consists on geometric evaluation of turbulent, transient, two-dimensional, incompressible and forced convective flows over triangular arrangements of square bluff bodies of size D employing Constructal Design. The main purpose is to evaluate the influence of the geometry of the arrangement over drag coefficient (C D) and Nuss...

This work contributes to the discussion on how and why tree networks in drainage basin arises in nature. A fully deterministic erosion model recently developed was used to explain the spontaneous origin of river networks, which until then was assumed to be due to the optimal reduction of the flow resistance in a area to point flow. A random evoluti...

This paper presents a network analysis of the scientific publications, co-authorship and citations associated to the word “constructal” that appears in Journals between the years 1996 to 2016 using search engine recognized in the international academic community. The constructed networks consider the existing relationships between authors and the n...

Why do individuals come to live (to move) together, to organize? Here, we propose that organization is a reflection of the physics reality (bio and nonbio) that it takes less power (useful energy, fuel, food, and exergy) to move 1 unit of mass in bulk than to move 1 unit individually. The objective of this work is to establish the connection betwee...

The Constructal law ─ “For a finite-size system to persist in time (to live), it must evolve in such a way that it provides easier access to the imposed (global) currents that flow through it”─ has been stated by Prof. Adrian Bejan in 1996. According to Bejan, 2016, “we work with colleagues to create new things that facililate movement for everybod...

O presente estudo avaliou o desempenho de uma unidade biodigestora em escala real, tratando dejetos da suinocultura, através da (i) caracterização de parâmetros físico-químicos influentes no biodigestor, assim como pela (ii) medição a produção de biogás gerado pelos dejetos da granja. Localizada no município de Carambeí-PR, a granja possui uma médi...

This work presents the development and analysis of constructal microchannel network architectures for heat dissipation. The network configurations are characterized by multiple flow ramifications and changes in length and hydraulic diameter scales through each ramification level. Architectures investigated experimentally in the past years have adop...

This paper presents a network analysis of the scientific publications, co-authorship and citations associated to the word “constructal” that appears in Journals between the years 1996 to 2016 using search engine recognized in the international academic community. The constructed networks consider the existing relationships between authors and the n...

Inequality " is a common observation about us, as members of society. In this article, we unify physics with economics by showing that the distribution of wealth is related proportionally to the movement of all the streams of a live society. The hierarchical distribution of wealth on the earth happens naturally. Hierarchy is unavoidable, with stayi...

Inequality " is a common observation about us, as members of society. In this article, we unify physics with economics by showing that the distribution of wealth is related proportionally to the movement of all the streams of a live society. The hierarchical distribution of wealth on the earth happens naturally. Hierarchy is unavoidable, with stayi...

This paper presents the constructal evolution of elementary system's configurations that originates dendritic networks for volume-to-point fluxes. Highly permeable incrustations evolve to facilitate a generic chemical substance's flux in a finite and impermeable tissue. The evolutionary process is guided by a genetic algorithm with the use of genet...

Physics is concise, simple, unambiguous, and constantly improving. Yet, confusion reigns in the field especially with respect to complexity and the second law of thermodynamics. In this paper, we step back and take a look at these notions—their meaning and definition—on the background provided by nature and thermodynamics. We review the central con...

While criteria pollutants have established emission limits for motorcycles in Brazil, aldehydes limits have not been established and conclusive studies have not been found in the existing literature, despite the growing number of motorcycles using flex fuel in Brazil. This work presents results for the emissions of criteria pollutants, such as carb...

Gasoline direct injection (GDI) vehicles are considered to be one of the solutions for engine optimization with regard to fuel consumption. This combustion system potentially provides, depending on the duty cycle, an improvement in fuel economy of 5 – 10%. In Brazil, mainly due to new requirements to reduce consumption imposed by the Inovar Auto au...

Motorcycle sales have increased consistently during the last decade mostly in developing countries, especially in the BRICS. Low cost and less fuel consumption comparing to cars associated to the economic growth are the main reason for such trend. Emission limits have become stricter and the use of gas after treatment devices is widely present in n...

People like to say that we cannot witness evolution because it occurred over a timescale immensely greater than human experience. Here, we show that it is possible to witness, explain, and predict evolution by focusing on technology evolution. We review the evolution of heat transfer devices from the point of view of the constructal law of design a...

This study aims to evaluate the capacitive measurement method at low frequencies for determining the moisture content in soybeans. Furthermore, a technique for measuring the moisture content of soybeans at different temperatures is proposed. A practical cylindrical capacitor was designed for the experiments. Capacitive measurements at frequencies o...

In order to comply with the introduction of new emission limits, motorcycles have been equipped with electronic injection systems and three-way catalytic converters for emissions abatement. However, these converters produce unwanted reactions, such as the formation of ammonia. This paper was focused on ammonia emission reduction in motorcycles. To...

A heat pump that is coupled thermally with the ground extracts heat from the soil in winter, and discharges heat in the summer. The coupling is made through a buried heat exchanger. In this paper we explore the idea of using a single heat exchanger that serves more than one heat pump. Each heat pump draws its mass flow rate from the heat exchanger...

Drainage basins are systems that collect water over a finite area and convey it to lower altitudes by gravity. Large-scale basins are so important that they became subject of a scientific field called hydrology (e.g., [1]). Small-scale basins, like the ephemeral set of channels present in superficial runoff water, are also important since they carr...

This paper shows that the dendritic patterns formed by low-resistance channels in a river drainage basin are reproducible and can be deduced from a single principle that acts at every step in the development of the pattern: the constrained minimization of global resistance in area-to-point flow. The river basin is modeled as a two-dimensional terri...

The function of many natural flow systems is to connect by a fluid flow a finite-size volume and one point. This paper outlines a strategy for constructing the architecture of the volume-to-point path such that the flow resistance is minimal (constructal theory1). The given volume is viewed as an assembly of volume elements of various sizes. The ma...

A fully determinisitc erosion model recently developed was used to explain the natural creation of river networks, which was assumed to be due to the optimal reduction of the flow resistance in a area to point flow. This work adds to this discussion, modifying the model to a fully random approach. The results showed that randomness does not create...

In this work we studied the phenol sorption from contaminated water onto modified clay mineral vermiculite and bentonite by insertion of hexadecyltrimethylammonium in the interlayer of clays. The non modified clays showed negligible interaction with phenol. The experimental data were treated using the Freunlich equation which had a good fit. The re...

In Celebration Professor Adrian Bejan on his 60th birthday Good theory grows out of freedom and fun. Adrian Bejan was born and raised on the Danube, in Galati, Romania, under a dictatorial communist regime. The son of a veterinarian (his father) and a pharmacist (his mother), he quickly showed inclination for analytical work, excelling in school. F...

This paper describes the geometric optimization of the internal structure of a volume that generates heat at every point and is cooled by a single stream. According to the constructal method, the optimization of the cooling design is organized in a sequence of steps that begins with the smallest volume element and continues with larger assemblies (...

A thermodynamic analysis (first and second laws) was performed for a coke dry quenching (CDQ) unit with all data obtained in the site and under the unit normal operating conditions. Expressions to evaluate the coke specific heat, enthalpy, entropy and physical and chemical exergies, as well as particulate material (dust) formation indices, and the...

Typescript. Thesis (Ph. D.)--Duke University, 1999. Vita. Includes bibliographical references (leaves 145-150).

This article reports a numerical study of the geometric minimization of the resistance to Darcy flow between a finite-size volume and one point. The volume is two dimensional and contains materials with several permeabilities. The optimization starts with the smallest volume subsystem, and proceeds coward larger subsystems (assemblies) until the gi...

This paper reports the solution to the fundamental problem of how to maximize the mechanical power extracted from a hot single-phase stream when the total heat transfer area bathed by the stream is constrained. It is shown that the optimization has two degrees of freedom: the shape of the stream temperature distribution as a function of the length...

This paper addresses the fundamental problem of how to connect a heat generating volume to a point heat sink by using a finite amount of high-conductivity material that can be distributed through the volume. The problem is one of optimizing the access (or minimizing the thermal resistance) between a finite-size volume and one point. The solution is...

This work analyzes the process of soybean moisture content determination based on its dielectric property. It establishes a method for measuring bulk soybean humidity by means of capacitance measurement. The influence of external factors such as temperature and grain type is verified. Resumo  Este trabalho analisa a o processo de determinação da u...