Alexandre Kupka da Silva
Universidade Federal de Santa Catarina – UFSC, BrasilOn the use of non-intrusive machine learning techniques applied to phase change processes
On the use of non-intrusive machine learning techniques applied to phase change processes
Short description: This talk will focus on applying machine learning and computer vision to phase change processes. It will demonstrate that simple, non-optimized neural networks can classify instantaneous boiling regimes, detect the onset of boiling crises, and quantify heat flux from visualization, all using low-speed, low-resolution frames.
Growth rate and dynamics of isolated vapour bubbles in a shear flow in microgravity
Short description: Presentation of an experiment we performed on an isolated vapour bubble nucleated on a heated wall in a shear flow in microgravity conditions. This experiment was performed on the International Space Station under the supervision of the European Space Agency and in collaboration with other colleagues. We will focus on experiments with a shear flow, describing the bubble’s growth, sliding along the wall and detachment by coalescence. We will compare the experimental results with theoretical models and numerical simulations.
Syngas production by biomass gasification, and sorption-enhanced CO2 removal for H2 enrichment
Short description: The keynote lecture will deal with the following main aspects: i) biomass gasification in terms of general concepts, chemical reactions, production and uses of syngas; ii) results from a demonstration biomass gasifier (1.5 MWth), in terms of syngas composition, heating value and yield, with an eye to the chemical speciation of tar compounds; iii) sorption-enhanced gasification in dual interconnected fluidised beds, aimed at CaO-based CO2 capture for the enrichment of syngas in H2.
Provisional Talk title: Experimental investigation of particle-laden flows for the understanding of scaling formation in pipes and valves.
Short description: Solid-liquid flows are ubiquitous in nature and technology. Different flow behaviors and patterns can be observed depending on parameters such as concentration, density ratios and time scales. Complexity increases when the discrete particles are formed by a chemical reaction occurring within the flow. The particles are nucleated either at the wall or at the bulk of the fluid. These particles can grow, agglomerate or deposit along the flow path. This phenomenon of scaling formation at high Reynolds numbers depends on pressure, temperature, salt concentration and on the local flow and turbulent structures. This talk will address the experimental investigation of this problem, which is still poorly understood. In the oil and gas industry, valves, separation equipment and heat exchangers are prone to blockage due to scale formation. A thorough understanding of this phenomenon is fundamental for the development of control and mitigation strategies.
Application of Phase Field LBM for Simulations of Multiphase Flows and Liquid-Vapor Phase Change Processes
Short description: In this theme, we will present the Phase Field LBM formulation used in our research group. Thereafter, results obtained from the simulation of multiphase flows will be presented, including isothermal multiphase flows and liquid-vapor phase-change processes. The main goal is to present LBM results for physical problems, considering real operational conditions and comparing numerical results with experimental data.
Algebraic Multiscale Finite Volume Methods for Numerical Modelling of Multiphase Flows in Porous Media
Short description: The numerical modelling and simulation of multiphase flows in complex porous media for various industrial and environmental applications, including oil and gas recovery, contaminant transport, nuclear waste disposal, and geothermal energy production, is challenging. This class of problems involves complex geometries and geological features associated with highly heterogeneous and anisotropic reservoirs. The current models in industrial applications include millions or even billions of degrees of freedom, resulting in very large-scale problems, and the systems of algebraic equations originating from their discretization are typically ill-conditioned, requiring significant computational resources and simulation times that can sometimes be prohibitive. A possible approach to address these challenges involves using multiscale techniques, either as reduced-order models or as preconditioners for high-fidelity models. This talk will present some recent achievements of our research group, in High-Performance Computing in Computational Mechanics – PADMEC, related to the development of robust locally conservative algebraic multiscale and multilevel methods.
Next-Generation Latent Heat Thermal Energy Storage Systems Enabled by Additive Manufacturing
Short description: This presentation explores the use of additive manufacturing to advance latent heat thermal energy storage systems. By moving beyond the limitations of conventional fabrication methods, more compact and efficient designs with enhanced heat transfer performance can be achieved. This approach offers a new direction for the design and application of thermal energy storage technologies.
Design efficient, smart and economic thermal energy storage: from material to application
Short description: This presentation will give a multi-scale, research-focused roadmap for designing efficient, smart, cost-effective thermal energy storage systems. It will examine advanced phase-change materials (encapsulation, composites, and stabilization strategies) and high-conductivity enhancements (metal foams, high-aspect additives, and porous matrices). Experimental methods and non-intrusive diagnostics will be discussed for resolving coupled temperature–velocity fields, validation of heat-transfer enhancements, and uncertainty quantification. Regarding modeling and control, it will couple multi-physics simulations, reduced-order models for system integration, and control strategies for PV-thermal and building-scale applications. The lecture concludes with techno-economic assessments, scalability challenges, and research priorities to accelerate the deployment of sustainable TES technologies.
High-fidelity simulations of supersonic turbines: characterization of supersonic boundary layers and shock-boundary layer interactions
Short Description: Supersonic turbines find application in high-speed propulsion and power generation systems. This talk will present a detailed analysis of the supersonic boundary layers and shock-boundary layer interactions (SBLIs) forming over the curved surfaces of supersonic turbines. Studies of SBLIs have been sought mainly for canonical configurations such as oblique shocks impinging on flat plates. Although these flow configurations allow an assessment of relevant physical mechanisms taking place in turbulent supersonic flows, understanding the physics of SBLI phenomena for more realistic configurations with wall curvature is essential to develop efficient supersonic fluid machinery, including the development of effective cooling strategies and active flow control for multi-point operation.