Anton Vernet

Universitat Rovira i Virgili | URV · Department of Mechanical Engineering

Dairy proteins are commonly used to stabilize oil-in-water (O/W) emulsions, which can be replaced by other sustainable sources of proteins, such as insects. This study investigated the potential of lesser mealworm protein concentrate (LMPC) as a sustainable alternative to whey protein isolate (WPI) in stabilizing oil-in-water (O/W) emulsions using...

The ability to accurately predict daily solar radiation reaching the earth’s surface is essential in applications such as solar power generation. Given their ease of use, many empirical models have been proposed based on different dependent variables such as cloud cover, daily temperature range, etc. In this study we evaluate 23 of these models for...

The three velocity components in a fluid plane can be measured by applying Digital Image Plane Holography. This technique is limited by the laser coherence length, which reduces its application with high speed lasers that, generally, have a very short coherence length. In addition, the use of a double cavity can also imply a small wavelength differ...

Classical pollutant dispersion models, based on the numerical resolution of some approximate form of the momentum, energy and chemical species conservation equations, are usually limited by incomplete descriptions of the atmospheric boundary layer hydrodynamics, partial characterizations of the emission inventories and, often, high computational co...

The present work studies numerically the dynamics and shape evolution of long flexible fibers suspended in a Newtonian viscous cellular flow using a particle-level fiber simulation technique. The fiber is modeled as a chain of massless rigid cylindrical segments connected by ball and socket joints; one-way coupling between the fibers and the flow i...

In this paper, we analyse the flow in a cylindrical cavity of aspect ratio H / R = 2, with a top lid rotating with a sinusoidal time-varying speed. The Reynolds numbers, based on the time-averaged rotating speed and the radius of the cavity (Re = $$ \Omega _0 R^2/\nu $$ Ω 0 R 2 / ν ) are 2800, 3500 and 4100. Particle Image velocimetry measurements...

The scalar transfer rate from a bubble to a quiescent fluid with Carreau rheological behavior is studied here with Bond and Galilei number values respectively equal to 30 and 2 and a non-dimensional inelastic time constant (λ) equal to 6. Under these conditions the bubble dynamics regime stays within the steady and oscillatory areas. Navier Stokes...

This study analyzes experimentally the deposition of magnetic beads on the walls of a square microchannel by the action of a nearby cubical magnet. The deposition has been studied for different magnetic bead sizes, flow rates, magnetic conditions and with solutions of magnetic and non-magnetic particles. Images of the time evolution of the depositi...

A main route for SARS-CoV-2 (severe acute respiratory syndrome coronavirus) transmission involves airborne droplets and aerosols generated when a person talks, coughs, or sneezes. The residence time and spatial extent of these virus-laden aerosols are mainly controlled by their size and the ability of the background flow to disperse them. Therefore...

Airborne particles are a major route for transmission of COVID-19 and many other infectious diseases. When a person talks, sings, coughs, or sneezes, nasal and throat secretions are spewed into the air. After a short initial fragmentation stage, the expelled material is mostly composed of spherical particles of different sizes. While the dynamics o...

Maritime activity is known to increase pollutant concentration levels in neighboring cities. In major touristic destinations, the singular need of cruise liners to keep supplying energy to on-board services and amenities while docked, has raised concerns about this industry contribution to pollutant emissions. To estimate the impact of port activit...

During the last decade there has been a noticeable increase in the number and use of smartphones around the world, a fact evinced in the latest reports by the Groupe Spéciale Mobile Association (GSMA). Nowadays, 1 in 2 people in the world own and use a smartphone.

Background and objective: To increase the success rate of invasive mechanical ventilation weaning in critically ill patients using Machine Learning models capable of accurately predicting the outcome of programmed extubations. Methods: The study population was adult patients admitted to the Intensive Care Unit. Target events were programmed extu...

Objective To assess the effect of HIV infection and combined antiretroviral therapy (c-ART) on various proatherogenic biomarkers and lipids and to investigate their relationship with subclinical atherosclerosis in a cohort of treatment-naive HIV-infected patients. Methods We performed a prospective, comparative, multicenter study of 2 groups of tr...

The present work analyzes numerical simulations of long flexible fibers in two-dimensional flows. The focus is on the frequency at which caustics occur and the characterization of the collisions among fibers. The continuous flexible fibers are modeled as a set of connected rigid cylinders, where forces are applied to the center of mass of each cyli...

This paper analyses the local and time-dependent behavior of large-scale structures responsible for liquid circulation in gas-water flow of a 3-D cylindrical bubble column of high aspect ratio with a multiple orifice for uniform aeration. The large-scale flow structures play an important role in the mixing and the mass transfer while coherent struc...

In this work, a qualitative and quantitative characterization of the three-dimensional flow in a lid-driven cylindrical cavity with different optical techniques is presented. Mach–Zehnder interferometry and photographic techniques have been used for a qualitative description of some flow features. However, the real challenge is to obtain quantitati...

We experimentally study the time evolution of the distance between two identical spheres settling down in polyacrylamide shear-thinning solutions in mixtures of water and glycerin. In order to analyze the behavior of the spheres under different rheological conditions, we varied the concentration of the polymer and glycerin. To examine the influence...

Quantification of mass transfer processes across micro-porous membranes can give valuable insight in applications of industrial and medical relevance. In this paper, a hybrid lattice Boltzmann-Finite differences (LBM-FD) code with non-uniform grid that simulates the mass transfer on a chip-like micro-device with an embedded micro-porous membrane ha...

Numerical simulations of long flexible fibers are presented for two-dimensional flows, focusing on the frequency at which caustics occur and the collisions between fibers. Both phenomena are also related to clustering. The steady analytical velocity fields correspond to the Arnold-Beltrami-Childress flows. A wide range of Stokes (St) numbers are us...

The numerical prediction of mass transfer rates of gas components within the liquid phase in a stirred two-phase flow reactor is presented. Experiments have been conducted to determine the flow regime and the number and sizes of the bubbles formed under different conditions. The dynamic field of the two-phase flow was obtained through numerical sim...

Numerical simulations of long flexible fibers are performed in two-dimensional analytical flow fields. The fibers are modelled as a set of rigid segments, with relative motion of segments providing the fiber with flexibility. Forces are applied to the mass center of each segment, and the numerical model ensures fiber continuity and conservation of...

The relationship between caustics formation and clustering for flexible fibers with high aspect ratio in two-dimensional flow fields is studied through numerical simulation. The fibers are modeled as a set of rigid cylinders, thus providing flexibility to the fiber. Forces are applied to the center of mass of each cylinder, determining cylinder mot...

This study presents the numerical prediction of the mass transfer rates of hydrogen and carbon monoxide within the liquid phase in a small-scale stirred tank reactor for large rotation rates. A transparent model of the reactor has been used to carry out experiments in order to determine the flow regime and the number and the sizes of the bubbles fo...

This work presents a numerical method to compute the multiphase flow with phase change in a wall-heated pipe. The volume fractions and velocities of the three different phases (gas, liquid and solid) and the common temperature and pressure are computed along the pipeline. The line, where multiple heating jackets are installed, is fed with a liquid-...

The present work studies numerically the concentration distributions of long flexible fibers in two analytical flow fields. Fibers are modeled as a set of rigid cylinders, resulting in a continuous flexible fiber. Forces are applied to the center of mass of each cylinder, thus determining cylinder motion and fiber deformation using a fourth-order R...

Turbulent diffusion dominates mixing at high molecular Schmidt numbers. When solving the Reynolds averaged Navier-Stokes equations, one of the key parameters for the correct simulation of mixing is the turbulent Schmidt number (Sct). In the case of the k-e turbulence model, many CFD packages suggest a value of 0.7 for Sct. However, it has been demo...

In this study we analyze experiments and numerical simulations of steady and unsteady mixed convection flow in a cubical cavity located at the bottom of a square channel. The Reynolds numbers based on the mean flow velocity and the channel width are in the range 100 ⩽ Re ⩽ 1500 and the Richardson numbers vary within 0.1 ⩽ Ri ⩽ 10. Particle Image Ve...

In this paper a new model to predict the wake of vertical axis wind turbines (VAWT) is proposed and analysed. The model is based on the actuator disk and the Double Multiple Stream Tube methods. Specifically, the model, denoted as Multiple Actuator Block, is based on the definition, inside the computational domain, of multiple parallelepipedic bloc...

Alginate microparticles as flow seeding fulfil all the requirements that are recommended for the velocity measurements in Particle Image Velocimetry (PIV). These spherical microparticles offer the advantage of being environmentally friendly, having excellent seeding properties and they can be produced via a very simple process. In the present study...

In this paper we analyse, numerically and experimentally, the laminar reactive flow in a cylindrical cavity with a rotating end wall. A basic solution is initially in the cavity and an acid solution is introduced at very low velocity through the center of the stationary endwall when the flow in the cavity is at the steady state. The effect of the d...

Turbulent diffusion dominates mixing at high molecular Schmidt numbers. When solving the Reynolds averaged Navier-Stokes equations, one of the key parameters for the correct simulation of mixing is the turbulent Schmidt number (Sct). In the case of the k-ϵ turbulence model, many CFD packages suggest a value of 0.7 for Sct. However, it has been demo...

Thrombus formation is a multiscale phenomenon triggered by platelet deposition over a protrombotic surface (eg. a ruptured atherosclerotic plaque). Despite the medical urgency for computational tools that aid in the early diagnosis of thrombotic events, the integration of computational models of thrombus formation at different scales requires a com...

Validation studies are prerequisites for computational fluid dynamics (CFD) simulations to be accepted as part of clinical decision-making. This paper reports on the 2011 edition of the Virtual Intracranial Stenting Challenge. The challenge aimed to assess the reproducibility with which research groups can simulate the velocity field in an intracra...

The wake generated by a vertical axis wind turbine is investigated experimen-tally and numerically. The experiments were conducted in an open-jet wind tunnel. The selected velocity is 4.83 m/s. In this study, a model of a commercial turbine developed by KLIUX energies company was tested. The turbine has 8 twisted blades. The diame-ter and height ar...

The heat transfer analysis and temperature distribution inside printed circuit board (PCB) enclosures for different geometries was investigated in this paper. Herein, the computational fluid dynamic (CFD) solver caffa3d.MB was employed to simulate the 3D incompressible Navier-Stokes equations. The numerical method uses a spatial discretization base...

The objective of this paper is to experimentally investigate the enhancement of thermal conductivity in the binary working pair (NH3 + LiNO3) by adding carbon nanotubes (CNTs). A stable distribution of CNTs in the base fluid is achieved by surface modification of CNTs through oxidation. The key parameters are the concentrations of NH3 and CNTs in w...

Based on the increasing interest in urban environmental technologies the study of small scale vertical axis wind turbines (VAWTs) presents motivating challenges. In this paper we present the characteristics and potentials of an open jet wind tunnel built in the laboratories of the ECoMMFiT 1 research group in Tarragona (Spain). The wind tunnel has...

Based on the increasing interest in urban environmental technologies the study of small scale vertical axis wind turbines (VAWTs) presents motivating challenges. In this paper we present the characteristics and potentials of an open jet wind tunnel built in the laboratories of the ECoMMFiT 1 research group in Tarragona (Spain). The wind tunnel has...

The thermal conductivity of NH3 + LiNO3 and NH3 + LiNO3 + H2O mixtures with an ammonia mass fraction between 0.3 and 0.6 was measured at temperatures from 303.15 K to 353.15 K at 1.5 MPa, using a relative transient hot wire apparatus. The apparatus and method were validated by comparing the measured values of the thermal conductivity of pure water,...

Aortic coarctation is a congenital condition in which the aorta is narrowed. The pressure drop through the aorta depends on the extension of this narrowing. Therefore, severe coarctations have im-portant side-effects on the hemodynamic conditions of the circulatory system. The Computational Fluid Dynamics (CFD) simulation of the hemodynamics in a p...

We analyse a database obtained from a direct numerical simulation of the reacting flow in a plane channel at low Reynolds number (Reτ = 180). One reactant is released along a line source at the center of the channel and the other near the walls of the channel. This distribution produces two reacting mass transfer mixing layers. The fluctuations of...

Fully implicit finite volume method is used for solving 3D incompressible Navier–Stokes equations inside Printed Circuit Board (PCB) enclosures to understand turbulent flows, heat transport and design techniques to improve cooling effectiveness of electronic devices. The numerical method caffa3d [1] uses, a spatial discretization based on block-str...

Alginate microparticles as flow seeding fulfil all the requirements that are recommended for the velocity measurements in Particle Image Velocimetry (PIV). These spherical microparticles offer the advantage of being environmentally friendly, having excellent seeding properties and they can be produced via a very simple process. In the present study...

The thermal conductivity of NH3 + H2O mixtures (with 0.1–0.5 mass fraction ammonia) was measured at temperatures between 293.15 K and 313.15 K using a transient hot-wire apparatus. The apparatus and method were validated by comparing the measured values of the thermal conductivity of pure water and water + lithium nitrate mixtures with published va...

Recent technology advancements in Particle Image Velocimetry (PIV) technique offers a new possibility to study the complex turbulent flows over a wide range of scales. It can be used for the estimation of the turbulent kinetic energy dissipation rate including spatial derivatives of the velocity fluctuation components. In this study the flow charac...

A three-dimensional numerical simulation study for both laminar steady and unsteady regimes has been carried out for the mixed convective flow over a three-dimensional cubical open cavity. The cavity is heated from below at constant temperature while the other walls are adiabatic. The numerical simulation has been done using a three-dimensional inc...

CFD predictions of the flow in cerebral aneurysms can help to analyze the mechanisms of growth and rupture and the degree of stress for a given flow conditions and to compare and to propose different stenting treatments. In this work we simulated the flow in a model of cerebral aneurysms of a real patient in six different conditions. One case corre...

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Time-Resolved Particle Image Velocimetry (TRPIV) has been used to investigate the flow inside the suction chamber of an external gear pump where the movement of the fluid through the pump is maintained by the rotation of the gears. The main purpose of this paper is to study the characteristics of the complex flow pattern of this pump system in orde...

The flow in the suction chamber of an external gearpump is numerically analysed. The evolution of the boundaries of the domain is very complex, and an arbitrary Lagrangian–Eulerian (ALE) formulation is used with mesh deformation and local remeshing. Nevertheless, a mesh replacement strategy is also adopted in order to avoid skewed meshes and allow...

a b s t r a c t A numerical study has been carried out to analyze the effects of mixed convective flow over a three-dimensional cavity that lies at the bottom of a horizontal channel. The vertical walls of the cavity are iso-thermal and all other walls are adiabatic. The cavity is assumed to be cubic in geometry and the flow is laminar and incompre...

a b s t r a c t We analyzed a database of a direct numerical simulation of natural convection in a vertical channel. The flow is driven by a constant temperature difference imposed at the walls (Ra = 5.4 Â 10 5 , Pr = 0.7). The averaged flow and turbulent statistics are in good agreement with previous direct numerical simulations reported in the li...

A method combining proper orthogonal decomposition (POD) and Fuzzy Clustering (FC) is used as a pattern recognition technique, in order to identify vortex modes in digital particle image velocimetry (DPIV) data, obtained in the wake of a long flexible circular cylinder undergoing vortex-induced vibrations. The POD allows a low-dimensional descripti...

The effect of stationary cylindrical rods located at the centerline axis on the vortex breakdown (VB) in a closed flow is studied experimentally and numerically. The flow takes place in a cylindrical container with a rotating end wall. The dimensionless numbers characterizing the dynamics of the system are the Reynolds number, based on the angular...

a b s t r a c t In this paper, we analyze the influence of aiding and opposing buoyancy on the statistics of the wall transfer rates in a mixed convection turbulent flow at low Reynolds numbers in a vertical plane channel. The analysis is carried out using a database obtained from direct numerical simulations performed with a second-order finite vo...

The use of air bubbles for the analysis of the turbulence in the suction chamber of a gear pump with Time Resolved Particle Image Velocimetry (TRPIV) is considered. It is the first time, as far as the authors know, that the flow inside a gear pump is observed with a non-intrusive technique. Although there are drawbacks of using air bubbles as flow...