1º DIA: Segunda-feira 23/09 | |
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08:30 – 9:30 | Registro e recebimento dos kits |
09:00 – 9:30 | Intervenção artística (Comitê de Ações Culturais – FESJ/UNESP) |
9:30 – 10:30 | Cerimônia de abertura |
10:30 – 10:45 | Intervenção artística (Comitê de Ações Culturais – FESJ/UNESP) |
10:45 – 12:00 | Palestra: Prof. Jorge Peixinho (ENSAM – Paris) Transition to turbulence in pipe flow and the effect of a wall-jet periodic disturbance |
Abstract The laminar flow in a straight pipe of circular cross-section leads to an elegant solution in the form of a parabolic velocity profile. Many physicists and engineers have verified this velocity profile and the associated Hagen-Poiseuille pressure drop law. When the flow rate increases with a low level of disturbance at the pipe inlet, the flow stays laminar, even at large velocities. However, when disturbances are present or artificially added, a sudden transition to turbulence is observed. In this presentation, we will describe the effect of various disturbances in pipe flow. Specifically, the effect of a wall-jet periodic injection through a small orifice in the wall, sometimes called synthetic jet, will be presented and compared to other types of disturbances. In a second part of the presentation, experiments and numerical simulations of the transition to turbulence in pipes with expansions, smooth of abrupt expansion, will be also examined with special attention to the role of the corner recirculation regions on the transition to turbulence. |
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12:00 – 14:00 | Pausa para almoço |
14:00 – 15:40 | Sessão técnica |
14:00 – 14:20 – EPTT2024-0007 STABILITY OF LIQUID SHEETS IN FUEL INJECTORS
14:20 – 14:40 – EPTT2024-0027 On the effect of turbulence modeling on the hemodynamics of intracranial aneurysms 14:40 – 15:00 – EPTT2024-0002 PRESSURE FIELD IN A CENTRIFUGAL PUMP COMPUTED FROM PARTICLE IMAGE VELOCIMETRY 15:00 – 15:20 – EPTT2024-0015 NUMERICAL INVESTIGATION OF NATURAL GAS MIXING THROUGH A CURVED SUPERSONIC SEPARATOR WITH GEOMETRY VARIATION AND CENTRIFUGATION 15:20 – 15:40 – EPTT2024-0052 Neural Networks as Flow Controllers: a Study on Robustness |
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15:40 – 16:10 | Coffee Break e exibição de pôsteres |
16:10 – 17:25 | Palestra: Prof. Dwight Barkley (University of Warwick) Transition to turbulence and statistical phase transitions |
Abstract “What we really cannot do is deal with actual, wet water running through a pipe. That is the central problem which we ought to solve some day, and we have not.” This statement by Richard Feynman captures how the seemingly simple motion of fluid through a pipe can present such an immense scientific challenge. After years of missteps, controversies, and uncertainties, we are at long last converging on a unified and fascinating picture of the transition to turbulence in flows such as pipes, channels, and ducts. I will discuss recent developments that have established a deep connection between transition in subcritical shear flows and a class of non-equilibrium statistical phase transitions known as directed percolation. I will review important results in the field with focus on the spatio-temporal nature of the problem and how universality manifests itself. |
16:25 – 17:40Palestra: Prof. Elie Bou-Zeid (Princeton University)
2º DIA: Terça-feira 24/09 Sessão especial em Camada limite atmosférica |
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08:30 – 10:00 | Palestra: Prof. Bruno Carmo (USP) The physics and mathematical modelling of the atmospheric boundary layer |
Abstract The atmospheric boundary layer (ABL) is the lowest part of the Earth’s atmosphere, directly influenced by surface interactions, such as heat, moisture, and momentum exchange. Its behavior is crucial for understanding weather patterns, pollutant dispersion, and wind energy resources. The physics of the ABL is governed by complex processes, including turbulence, buoyancy, friction, and shear. These processes lead to rapid changes in temperature, wind speed, and humidity over short vertical distances. The ABL is often characterized by turbulent mixing, where energy is transferred between different scales of motion. This turbulent flow is responsible for transporting heat, moisture, and momentum between the surface and the free atmosphere above. A key challenge in ABL modeling is the accurate representation of surface boundary conditions, which strongly influence the turbulence regime. This is typically done using parameterization schemes that model the fluxes of momentum, heat, and moisture based on surface characteristics like roughness and vegetation. In this talk we will discuss the physics and the mathematical modelling of this highly important flow, highlighting some of its most relevant concepts and paving the way for the next talks of this special session. |
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10:00 – 10:30 | Coffee Break e exibição de pôsteres |
10:30 – 10:45 | Intervenção artística (Comitê de Ações Culturais – FESJ/UNESP) |
10:45 – 12:00 | Palestra: Prof. Marcelo Chamecki (UCLA) |
12:00 – 14:00 | Pausa para almoço |
14:00 – 15:40 | Sessão técnica |
14:00 – 14:20 – EPTT2024-0014 Turbulence Modeling in Nonpremixed Sooting Flames: Entrainment Effects and Implications
14:20 – 14:40 – EPTT2024-0012 Numerical Investigation of the Backward Facing Step Configuration Using ILES Methodology 14:40 – 15:00 – EPTT2024-0037 Influence of the bed slope on axisymmetric gravity current propagation 15:00 – 15:20 – EPTT2024-0016 A new CFD code for simulation of the neutral atmospheric boundary layer using the RaNS methodology 15:20 – 15:40 – EPTT2024-0032 Resolvent analysis of coherent structures in the atmospheric boundary layer considering Coriolis effects |
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15:40 – 16:10 | Coffee Break e exibição de pôsteres |
16:10 – 16:25 | Intervenção artística (Comitê de Ações Culturais – FESJ/UNESP) |
16:25 – 17:40 | Palestra: Prof. Elie Bou-Zeid |
17:40 – 18:00 | Anúncio de patrocinador (VersatusHPC) |
3º DIA: Quarta-feira 25/09 | |
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08:30 – 10:00 | Palestra: Prof. João L. F. Azevedo (ITA) |
10:00 – 10:30 | Coffee Break e exibição de pôsteres |
10:30 – 12:00 | Palestra: Prof. Fulvio Scarano (TU Delft) Quantitative flow visualisation for the study of transition and turbulence |
Abstract Flow visualisation has been one of the first approaches that reveal the complex flow patterns and dynamics occurring during flow transition and turbulence. The needed transformation of qualitative visualisations into quantitative measurements has initially required a dimensional downgrading (from 3D to planar and often point wise measurements). The advent of PIV has combined the ability to yield quantitative data with the observation of flow-field pattern. The constantly evolving velocity and vorticity patterns of transitional and turbulent flows could be captured, instantly and in a reasonably large measurement plane. The last two decades have 3D quantitative visualisation techniques emerging (Tomographic PIV, Lagrangian Particle Tracking) and their time-resolved variants (TR-TOMO-PIV and Shake-the-Box). The lecture presents the principles of such techniques in the context of transition and turbulent flow problems. A survey of applications is presented that ranges from roughness induced transition to turbulent skin friction control. An outlook describes the latest developments towards large-scale PIV by means of helium-filled soap bubbles (HFSB) for the study of complex problems directly in real-world conditions. |
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12:00 – 14:00 | Pausa para almoço |
14:00 – 15:40 | Sessão técnica |
14:00 – 14:20 – EPTT2024-0026 BOUNDARY LAYER TRANSITION AFFECTED BY A GAP
14:20 – 14:40 – EPTT2024-0013 A Study of Explicit Algebraic Reynolds Stress Models Applied to Aerodynamic Flows 14:40 – 15:00 – EPTT2024-0021 Investigation of Finite Wing Effects in Transitional Airfoil Flows Using the Lattice-Boltzmann Method 15:00 – 15:20 – EPTT2024-0024 Analysis of Extreme Events in the Boundary Layer of a NACA0012 at High Angle of Attack 15:20 – 15:40 – EPTT2024-0054 ON THE FORMATION OF A LAMINAR SEPARATION BUBBLE |
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15:40 – 16:10 | Coffee Break e exibição de pôsteres |
16:10 – 17:40 | Dr. Meelan Choudhari (NASA Langley Research Center) The Elephant in the Wind Tunnel: Reflections on Collaborative Approaches for Transition Modeling, from N-Factor Methods to the Transfer Function Tango |
Abstract Em breve. |
4º DIA: Quinta-feira 26/09 | |
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08:30 – 10:00 | Palestra: Prof. Roney Thompson (UFRJ) |
10:00 – 10:30 | Coffee Break e exibição de pôsteres |
10:30 – 10:45 | Intervenção artística (Comitê de Ações Culturais – FESJ/UNESP) |
10:45 – 12:00 | Palestra: Profa. Laurette Tuckerman (ESPCI – Paris) Patterns of Turbulence |
Abstract A standing wave pattern appears on the free surface of a fluid layer when it is subjected to vertical oscillation of sufficiently high amplitude. Like Taylor-Couette flow (TC) and Rayleigh-Benard convection (RB), the Faraday instability is one of the archetypical pattern-forming systems. Unlike TC and RB, the wavelength is controlled by the forcing frequency rather than by the fluid depth, making it easy to destabilize multiple wavelengths everywhere simultaneously. Starting in the 1990s, experimental realizations using this technique produced fascinating phenomena such as quasipatterns and superlattices. This sparked a renaissance of interest in Faraday waves, which led to new mathematical theories of pattern formation. However, the Faraday instability has been the subject of surprisingly little numerical study, lagging behind TC and RB by several decades. We will discuss some of the exotic patterns found in recent numerical simulations. The first 3D simulation reproduced hexagonal standing waves, which were succeeded by recurrent alternation between quasi-hexagonal and beaded striped patterns, interconnected by spatio-temporal symmetries. In a large domain, a pattern of square waves divides spontaneously into four subsquares with synchronized diagonal blocks or else can undergo a twisted sheared secondary instability. A liquid drop subjected to an oscillatory radial force comprises a spherical version of the Faraday instability. Simulations show Platonic solids alternating with their duals while precessing. |
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12:00 – 14:00 | Pausa para almoço |
14:00 – 15:40 | Sessão técnica |
14:00 – 14:20 – EPTT2024-0022 DYNAMICS OF H2 BUBBLES BASED ON VELOCITY FIELDS DURING WATER ELECTROLYSIS
14:20 – 14:40 – EPTT2024-0042 TURBULENCE CHARACTERISTICS ANALYSIS IN HORIZONTAL OIL-WATER CORE-ANNULAR FLOW VIA PARTICLE IMAGE VELOCIMETRY (PIV). 14:40 – 15:00 – EPTT2024-0025 Linear Stability Analysis of Viscoelastic Boundary Layer Flows 15:00 – 15:20 – EPTT2024-0047 STABILITY ANALYSIS OF OLDROYD-B FLUID PIPE FLOW 15:20 – 15:40 – EPTT2024-0028 STABILITY ANALYSIS OF OLDROYD-B AND GIESEKUS FLUIDS JET FLOW: LST AND DNS. |
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15:40 – 16:10 | Coffee Break e exibição de pôsteres |
16:10 – 17:40 | Palestra: Prof. Javier Jiménez (UPM) Fake turbulence |
Abstract Turbulence is a high-dimensional dynamical system with known equations of motion. It can be numerically integrated, but the simulation results are also high-dimensional and hard to interpret. Lower-dimensional models are not dynamical systems, because some dynamics is discarded in the projection, and a stochastic Perron-Frobenius operator substitutes the equations of motion. Using as example turbulent flows at moderate but non-trivial Reynolds number, we show that particularly deterministic projections can be identified by either Monte-Carlo or exhaustive testing, and can be interpreted as coherent structures. We also show that they can be used to construct data-driven ‘fake’ models that retain many of the statistical characteristics of the real flow. |
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18:00 – 19:00 | Assembleia ABCM |
5º DIA: Sexta-feira 27/09 | |
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08:30 – 9:30 | Palestra: Prof. Bruno Carmo (USP) Computational modelling and simulation of wind turbines and wind farm flows |
Abstract Computational modeling and simulation of wind turbines and wind farm flows have become essential tools for optimizing wind energy production, understanding aerodynamic interactions, and predicting wind turbine loads. Wind farms operate in complex and dynamic atmospheric environments, where interactions between the rotor blades and wind flow, as well as interactions between multiple turbines, are influenced by turbulence, wake effects, and atmospheric boundary layer phenomena. To address these challenges, computational fluid dynamics (CFD) and other numerical approaches are used to simulate the flow around turbines and within entire wind farms. One of the key challenges in wind farm simulations is the modeling of turbine wakes. As wind flows past a turbine, it generates a wake characterized by reduced wind speed and increased turbulence. These wakes can significantly impact downstream turbines, reducing their power output and increasing mechanical loads. To simulate wake interactions within a wind farm, different methods are employed, including actuator disk models, which represent turbines as porous disks that induce a momentum deficit in the flow, and full rotor-resolved CFD simulations, which capture detailed aerodynamic effects. Large eddy simulation (LES) is often used to model turbulence in the wind farm, providing insights into the effects of atmospheric conditions on wake formation and propagation. In this talk, we will address the computational techniques employed to simulate the operation of wind turbines and wind farms using different degrees of fidelity. We will discuss the differences in level of representation of the physics that each approach is able to deliver, as well as their computational cost. |
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9:30 – 10:15 | Coffee Break e exibição de pôsteres |
10:15 – 11:30 | Palestra: Prof. Daniel Rodríguez (UPM) New perspectives on instability of laminar separation bubbles: have we been missing something important? |
Abstract Decades of research have established the ubiquity of convective inflectional instability in laminar separation bubbles (LSBs) and its dominant role on the laminar-turbulent transition process. However, a plethora of additional dynamics including three-dimensionalisation of the mean flow, low-frequency breathing or self-excited vortex shedding have been observed as the key parameters, namely adverse pressure gradient, Reynolds number and incoming turbulence intensity, are varied; these additional dynamics cannot be fully explained by convective instability alone. To fill these gaps, global instability mechanisms of LSBs were proposed in the past, but most low- turbulence wind tunnel experiments either did not find evidence of their presence, or attributed the possible evidences to by-products of the inflectional instability. This talk will briefly revisit and depart from theoretically-predicted self-sustained linear instabilities of LSBs [1]. First, a geometrical criterion for the onset of absolutely unstable inflectional instability will be proposed [2], based on the relative position of the inflection point and the separation streamline. Recent results on non-linear and secondary instabilities of 3D separated flows will be then presented. They show that the spanwise distortion of the recirculation region, which is inherent to separated flows, strongly enhances inflectional instability, potentially leading to their absolute instability and to the appearance of a self-excited global oscillator [3]. This sequence triggers the laminar-turbulent transition without requiring any external disturbances or actuation, and also may define the dynamics in the presence of low-amplitude free-stream disturbances [4, 5]. The resulting LSBs agree well with those reported for low-turbulence wind-tunnel experiments without actuation at comparable conditions, which suggests that the inherent dynamics described by the self- excited instability might have been present and overlooked. Finally, some recent experimental works will be discussed under the light of the theoretical results with the aim of offering an enlarged perspective for future research. |
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11:30 – 12:00 | Encerramento |
Pôsteres
Aerodynamics
EPTT2024-0003 Using convolutional neural networks to predict airfoil dynamic stall response
EPTT2024-0008 Analysis of vorticity transport in separated flows over wind turbine airfoils using Detached-Eddy Simulations
EPTT2024-0023 Some experimental results of the impact caused by a rectangular bump on boundary layer transition.
EPTT2024-0040 A Numerical Simulation with OpenFOAM of a NACA0012 at High Reynolds number and critical angle of attack
EPTT2024-0055 Analysis of dynamic stall for a simplified single blade vertical axis wind turbine configuration
Hydrodynamic Instability
EPTT2024-0030 Development and validation of a linear stability analysis tool for compressible shear flows
EPTT2024-0045 LINEAR STABILITY ANALYSES OF GÖRTLER VORTICES IN NON-NEWTONIAN BOUNDARY LAYER FLOWS
EPTT2024-0056 Boundary integral simulations based on the vortex sheet formalism applied to track droplet interfaces in Hele-Shaw cells
Rheology and Non-Newtonian Fluid Mechanics
EPTT2024-0017 STUDY OF NON-NEWTONIAN FLUID FLOW STABILITY MODELED BY LPTT
Theoretical and Analytical Modeling
EPTT2024-0051 Prediction of Transition to Turbulence in Airfoils using Artificial Neural Networks
Turbulence
EPTT2024-0020 IMPLICIT LARGE EDDY SIMULATION: MODELING ANISOTROPIC TURBULENCE USING THE LATTICE BOLTZMANN METHOD
EPTT2024-0033 Numerical Study of a Toroidal Propeller
EPTT2024-0044 Investigation of Spanwise Periodic Transitional Airfoil Flows Using the Lattice-Boltzmann Method
EPTT2024-0050 Turbulent Channel flow with Coriolis force using Large-Eddy Simulation
Computational Fluid Dynamics
EPTT2024-0009 Methodology for defining optimal geometry of the ejector tee for purge
EPTT2024-0036 EVALUATION OF THE USE OF A FAST MULTIPOLE METHOD IN LAGRANGIAN SIMULATIONS
EPTT2024-0043 Aircraft thermal management: CFD analysis of the wing as a surface heat exchanger
Atmospheric Boundary Layer
EPTT2024-0048 Simulation of the Unstable Atmospheric Boundary Layer of Amazon Rainforest Using Large-Eddy Simulation