I am a Full Professor of Mechanical Engineering at the Federal University of Catalão in Brazil, where I collaborate with students and partners to solve practical flow, erosion, and heat-transfer problems through advanced CFD and experimentation. My background includes a Ph.D. and M.Sc. in Mechanical Engineering from the Federal University of Uberlândia, and my work has appeared in journals such as Wear, International Journal of Multiphase Flow, Mechanics Research Communications, International Communications in Heat and Mass Transfer, and Journal of Materials Research & Technology. I have been recognized with an Honorable Mention in the CAPES Thesis Award (Engineering III) and distinctions from ABCM in partnership with Embraer, and I actively serve as a peer reviewer. Recently, I’ve broadened my research into additive manufacturing—linking microstructure to mechanical performance—while continuing to design strategies that mitigate erosion and improve reliability in industrial systems.
Slurry pipe transport has directed the efforts of researchers for decades, not only for the practical impact of this problem, but also for the challenges in understanding and modelling the complex phenomena involved. The increase in computer power and the diffusion of multipurpose codes based on Computational Fluid Dynamics (CFD) have opened up the opportunity to gather information on slurry pipe flows at the local level, in contrast with the traditional approaches of simplified theoretical modelling which are mainly based on a macroscopic description of the flow. This review paper discusses the potential of CFD for simulating slurry pipe flows. A comprehensive description of the modelling methods will be presented, followed by an overview of significant publications on the topic. However, the main focus will be the assessment of the potential and the challenges of the CFD approach, underlying the essential interplay between CFD simulations and experiments, discussing the main sources of uncertainty of CFD models, and evaluating existing models based on their interpretative or predictive capacity. This work aims at providing a solid ground for students, academics, and professional engineers dealing with slurry pipe transport, but it will also provide a methodological approach that goes beyond the specific application.
This paper presents the first blind prediction stage of the Tidal Turbine Benchmarking Project being conducted and funded by the UK's EPSRC and Supergen ORE Hub. In this first stage, only steady flow conditions, at low and elevated turbulence (3.1%) levels, were considered. Prior to the blind prediction stage, a large laboratory scale experiment was conducted in which a highly instrumented 1.6m diameter tidal rotor was towed through a large towing tank in well-defined flow conditions with and without an upstream turbulence grid. Details of the test campaign and rotor design were released as part of this community blind prediction exercise. Participants were invited to use a range of engineering modelling approaches to simulate the performance and loads of the turbine. 26 submissions were received from 12 groups from across academia and industry using solution techniques ranging from blade resolved computational fluid dynamics through actuator line, boundary integral element methods, vortex methods to engineering Blade Element Momentum methods. The comparisons between experiments and blind predictions were extremely positive helping to provide validation and uncertainty estimates for the models, but also validating the experimental tests themselves. The exercise demonstrated that the experimental turbine data provides a robust data set against which researchers and design engineers can test their models and implementations to ensure robustness in their processes, helping to reduce uncertainty and provide increased confidence in engineering processes. Furthermore, the data set provides the basis by which modellers can evaluate and refine approaches.
Cyclone separators are widely used in fluid catalytic cracking (FCC) units due to their lack of moving parts and relatively low-pressure drop. However, cyclone separators are prone to erosion-related issues, which is a major drawback. In this paper, a large eddy simulation (LES) of the particle-gas flow in a cyclone separator is investigated using a four-way Euler-Lagrange approach to model inter-particle collisions and the exchange of momentum between particles and fluid. The effects of inter-particle and particle-wall collisions are characterized in terms of erosive wear. Additional effects involving the exchange of momentum between the fluid and the particles are also discussed. The results show that considering the interparticle collisions between solid particles may be the key to predicting erosion.
Additively manufactured components often exhibit microstructural heterogeneity, leading to anisotropy. Most works are dedicated to a specific feature, and a full characterization has not been addressed yet. This study characterizes these heterogeneities in a carbon steel part made by wire arc additive manufacturing (WAAM) and correlate them numerically with physical phenomena A deep microstructural, mechanical, and surface analysis was carried out for three main regions of the wall: top, middle and bottom. The cooling rate and the number of subsequent passes are the main factors influencing microstructure variation on the layers, steady-state regime was reached at layer 30. Electron backscatter diffraction (EBSD) analysis showed uniform grain orientation and similar size, with ferrite increasing from the top to the bottom, while the amount of retained austenite and cementite, decreased. The top region showed diverse microconstituents due to the absence of reheating cycles in the last layers. Microhardness values varied with average of 223.3, 176.3 and 187.6 HV0.1 for top, middle and bottom regions, respectively, the same trend was found in the simulation. Tensile tests indicated minor anisotropy in yield strength (YS) and ultimate tensile strength (UTS), but significant anisotropy in elongation. The anisotropic percentages of YS, UTS, and elongation come to 0.9 %, 0.4 %, and 10.9 %, respectively. Scanning electron microscopy (SEM) analysis presented ductile failure in both vertical and horizontal orientations. Surface characterization indicated similar topography on both sides of the wall. Overall, it exhibited homogeneous microstructural characteristics and surface topography, but heterogeneous mechanical properties, particularly in elongation.
Wear due to particles is often the key factor for pipeline failure. In this work, the effects of different sand particle concentration on the erosion of a vortex-chamber elbow are investigated numerically. Based on four-way-coupled simulations of the gas-solid flow, the comparison between the standard and vortex-chamber elbow results was performed and a detailed analysis of the mass loading influence on the penetration ratio was carried out. An important finding is that the addition of the vortex chamber significantly shows the efficiency of the cushioning effect. A comparison of the peak of penetration ratio in both elbow designs, for a mass loading of 1.0, indicates that the reduction was around 93% when the vortex chamber is present.
Partículas transportadas pneumaticamente são comumente responsáveis por desencadear \no processo de erosão por impactos na parede. Esses impactos resultam da interação \nfluido-partícula e a compreensão de seus mecanismos é a chave para mitigar os danos \ncausados pela erosão em aplicações de engenharia. Em geral, a erosão causada por impacto \nde partículas, que pode ocorrer em uma variedade de casos práticos, é frequentemente \no fator principal na falha de tubulações. Acessórios como cotovelos, por exemplo, são \nparticularmente propensos a problemas de erosão. Na primeira parte desta tese, as equações \nmédias de Reynolds transiente (URANS) são combinadas com um modelo lagrangeano \nestocástico de rastreamento de partículas considerando todos os processos elementares \nrelevantes (forças de arrasto e sustentação, rotação das partículas, colisões entre partículas, \ninterações partícula-parede, acoplamento entre as fases) para predizer numericamente o \nfenômeno erosivo em um cotovelo de 90 . Após uma validação detalhada do modelo de \nerosão com base nos resultados experimentais de Solnordal et al. (2015), vários outros \ncasos com diferentes rugosidades na parede e coeficientes de atrito estático e dinâmico \nsão apresentados para elucidar a natureza do processo erosivo. Para tal análise, foram \nutilizadas variáveis mais fundamentais e que estão relacionadas às interações partículaparede \n(velocidade de impacto, ângulo de impacto, frequência de impacto) para examinar \nos mecanismos básicos de erosão. Finalmente, para provar a importância da colisão entre \npartículas na erosão do cotovelo, diferentes cargas mássicas são simuladas. Especialmente \npara os casos com carga mássica elevada, resultados interessantes sobre a importância das \ncolisões entre partículas na erosão do cotovelo são abordados. Em uma segunda etapa, \npropomos um novo design para a parede da tubulação com o intuito de reduzir a erosão no \ncotovelo de 90 . Esta concepção consiste em torcer a parede do tubo ao longo do sentido \nprincipal do escoamento. Basicamente, tal configuração gera a rotação do fluido a montante \ndo cotovelo e, consequentemente, re-dispersa as partículas transportadas, evitando que se \nconcentrem diretamente em um único ponto no cotovelo. Com base em simulações com \nquatro vias de acoplamento, simulações são feitas para a configuração proposta. Para \ncompreender a natureza do processo erosivo na nova geometria, as variáveis relativas as \ninterações partícula-parede que foram mencionadas anteriormente também foram avaliadas. \nEm geral, verificou-se que as alterações no escoamento multifásico promovidas pela parede \ntorcida são efetivas na redução da erosão no cotovelo. As simulações numéricas revelam \nque a tubulação equipada com o tubo torcido reduz o pico de profundidade de erosão no \ncotovelo em até 33% quando comparado ao tubo convencional.
Swirling jets have numerous applications in industry. A better understanding of the generation and evolution of turbulent structures in jet flows is useful for engineering and theoretical reasons. This work is concerned with the physical analysis of a swirling jet by means of three-dimensional simulations using a pseudo-spectral method. The detailed structures of the flow could be visualized and the mechanisms leading to their formation and evolution are elucidated. A comparison between a swirling and so-called "natural" jet were carried out. The possibility of controlling the jet evolution by prescribing different perturbations to the initial conditions was assessed. The proximity of the inertial region to the inclination of -5/3 and the decay region were verified in the energy spectra.
