Joaquim Rigola

Joaquim Rigola
Universitat Politècnica de Catalunya | UPC · CTTC - Heat and Mass Transfer Technological Center

Professor

About

141
Publications
27,858
Reads
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1,400
Citations
Citations since 2016
56 Research Items
1024 Citations
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150

Publications

Publications (141)
Article
An investigation of various eddy viscosity models for accurate scale-resolving simulation of aerodynamics and aeroacoustics of a turbulent jet is presented. The models are considered from the perspective of solving the so-called gray area problem. This problem is related to nonphysical delay in the transition from Reynolds-averaged Navier–Stokes (R...
Conference Paper
In the present work, the separation efficiency analysis on particle-laden flows in the framework of LES and RANS modelling for an Inertial Particle Separator (IPS) device has been presented. The comparison of LES and RANS will allow us to study and assess both the advantages and disadvantages of these modelling techniques for the design and optimis...
Article
This paper presents a high-order finite volume method for solving linear elasticity problems on two-dimensional unstructured meshes. The method is designed to increase the effectiveness of finite volume methods in solving structural problems affected by shear locking. The particular feature of the proposed method is the use of Moving Least Squares...
Conference Paper
Full-text available
The present study investigates the effect of hydrogen addition to methane-air jet flame based on Sandia flame D. For this purpose, RANS simulations with a global four-step mechanism were first compared with other reduced (1-step, 2-step) and detailed mechanisms (DRM-19, GRI-Mech 3.0) using the standard − model. The accuracy of the simulations was f...
Conference Paper
The present work consists in the development of a highly efficient solar thermal flat plate solar collector [FPC] with transparent insulation materials [TIM] at high-temperature ranges (η at ∆T/G close to 0.1 Km 2 /W). The emphasis of the research is set on determining the combination of insulation materials that can boost the overall efficiency at...
Article
Full-text available
In this paper, a numerical model for the simulation of the cooking process of meat burgers and vegetarian patties by means of an IR laser beam is presented. The innovative cooking system is thought to be integrated within a 3‐D printer prototype where the food sample is placed on a rotating plate. The numerical model consists of two different tools...
Article
Full-text available
The breeding blanket is one of the fundamental components of a nuclear fusion reactor and is responsible for the fuel production, generating tritium through neutronic capture reaction between lithium and neutrons. Lithium is a liquid PbLi alloy and the helium formed as reaction by-product can coalesce into bubbles, generating a two-phase mixture wi...
Article
Full-text available
The present work demonstrates prototypes of highly efficient flat plate solar thermal collectors prototypes based on transparent insulation materials (TIM) technology for efficiency improvement and an overheating protection system. The design and optimization of the collectors have been numerically carried out using a previously developed simulatio...
Chapter
This work presents Direct Numerical Simulation of mass transfer in a bi-dispersed bubble swarm at high Reynolds number, by using a multiple marker level-set method. Transport equations are discretized by the finite-volume method on 3D collocated unstructured meshes. Interface capturing is performed by the unstructured conservative level-set method,...
Article
The present article presents a new analysis for the dispersion error and the methodology to evaluate it numerically. Here we present the spectral properties of several convective schemes, including non-linear ones, on Cartesian stretched grids for linear advection problems. Results obtained with this method when applied to uniform structured meshes...
Conference Paper
ECOSun project has as main objective a cost reduction of electricity and heat co-generation via a Concentrated Photovoltaic/Thermal (CPV-T) system by applying low-cost materials and advanced industrial manufacturing methods. In the CPV-T system, the solar radiation is captured in parabolic through concentrator based on a novel support structure fab...
Conference Paper
A novel conservative level-set method for saturated liquid-vapor phase change on unstructured meshes is introduced. Transport equations are discretized by the finite-volume method on collocated unstructured grids. Mass transfer promoted by thermal phase change is computed using the energy jump condition at the interface, as a function of the temper...
Chapter
Mass transfer processes in bubbly flows are relevant in both nature and industry. Multiple examples arise from the so-called unit operations of the chemical engineering, where bubble columns are used for separation processes, or as chemical and biochemical reactors.
Preprint
Full-text available
This article presents a new spectral analysis approach for dispersion error and a methodology to numerically evaluate it. In practice, this new analysis allows the numerical study of dispersion errors on all types of mesh and for multiple dimensions. Nonetheless, when mesh uniformity and one-dimensionality assumptions are imposed as in the classica...
Article
Full-text available
The operation of self-actuated valves in suction and discharge processes plays a crucial role in the thermal efficiency and structural reliability of hermetic reciprocating compressors. The present work provides a thorough description of an in-house numerical method based on a partitioned fluid-structure interaction algorithm intended to obtain hig...
Conference Paper
In order to develop advanced control strategies for complex thermal systems such as in the case of refrigeration and airconditioning systems, calibrated models against experimental measurements are necessary to reproduce with accuracy the behavior of the real plant, under static and dynamic conditions. Even if accurate information (e.g.: look-up ta...
Article
Full-text available
A level-set model is presented for simulating mass transfer or heat transfer in two-phase flows. The Navier-Stokes equations and mass transfer (or heat transfer) equation are discretized using a finite volume method on a collocated unstructured mesh, whereas a multiple marker level-set approach is used for interface capturing in bubble swarms. This...
Article
Direct Steam Generation (DSG) has attracted considerable attention in comparison with conventional technologies based on Heat Transfer Fluids (HTF) for electricity generation due to its higher temperatures. In this context, a detailed numerical model has been developed, not only for comparison and assessment purposes but also for optimization analy...
Chapter
This work presents Direct Numerical Simulation of mass transfer from buoyancy-driven bubbles rising in a wall-confined vertical channel, through a multiple markers level-set method. The Navier-Stokes equations and mass transfer equation are discretized using a finite volume method on a collocated unstructured mesh, whereas a multiple markers approa...
Poster
High performance flat plate solar thermal collectors Thermal applications are drawing increasing attention due to their high performance in energy storage density and energy conversion efficiency. Flat plate solar collector is an interesting technology due to its low cost, easy manufacturing and low maintenance. Current technology gives optimal per...
Article
This paper focuses on three-dimensional direct numerical simulations of rising bubbles in the wobbling regime, and the study of its dynamical behavior for Eötvös number 1 ≤ Eo ≤ 10 and Morton number 1e-11 ≤ M ≤ 1e-9. The computational methodology is based on a mass Conservative Level-Set method, whereas the spatial discretization of the computation...
Chapter
A nonuniform distribution of temperature field on a fluid-fluid interface leads to surface tension gradients, which induce shear stresses that produce the motion of a drop in the direction of the temperature gradient. This phenomenon is known as thermocapillary flow or Marangoni migration. In addition to its importance from a fundamental point of v...
Conference Paper
Full-text available
Simulation models and predictive tools need to be fast, accurate and robust at the same time. The models that have to provide numerical solutions under transient conditions for a long period of time need to be simple with the aim of minimizing the time respond, without losing the accuracy. Thus, previous experimental data and a calibration methodol...
Article
Full-text available
The simulation of HVAC systems is a powerful tool to improve the energy efficiency in buildings. The modelling of such systems faces several obstacles due to both the physical phenomenology present and the numerical resolution difficulties. The present work is an attempt to develop a robust, fast, and accurate model for HVAC systems that can intera...
Article
In this work, a conservative level-set finite-volume solver for interface-capturing is employed to perform the direct numerical simulation of Liquid Jets discharging into a quiescent air chamber. The scope is to propose a complete break-up regimes map entirely obtained from numerical simulations. The solver accounts for an adaptive mesh refinement...
Article
Within the framework of Low Thrust Cryogenic Propulsion (LTCP) systems, a low-temperature accumulator acting as thermal energy storage tank is an interesting option for cyclical processes under intermittent firings avoiding the use of turbopumps in the cryogenic stages. Thus, liquid propellant (oxygen, hydrogen or methane) can be gasified under a f...
Conference Paper
The present paper presents a numerical model to analyze the thermal and fluid dynamic behavior of a mechanical vapor compression MVC desalination system. The MVC desalination is a method to obtain distilled water using the evaporation and condensation processes at the same time, both occur at low pressure (values lower than atmospheric pressure). T...
Article
Full-text available
Determination of the optimal insulation thickness is of great relevance in many thermal engineering applications. In this paper, a simple optimization strategy based on the Lagrange multipliers is presented. The optimal set of thicknesses is analytically found for different constraints and objective functions of interest for the refrigeration indus...
Conference Paper
A level-set model is proposed for simulating interfacial heat or mass transfer in two-phase flows. The Navier-Stokes equations as well as the heat transfer or mass transfer equations are discretized using a finite-volume approach on a collocated unstructured mesh, whereas a multiple marker level-set methodology is introduced in order to avoid the n...
Conference Paper
Enhanced finite volume thermoelastic models, with emphasis on convergence acceleration and direct face gradient calculation, are presented. Second-order discretisation schemes are employed in time and space, and two different approaches to solve the linear system of equations have been implemented: a segregated method and a block-coupled method. Th...
Presentation
Bubbly flow with interfacial heat or mass transfer is a complex phenomenon, difficult to understand, predict or model. Experimental measurements of bubbly flows can be hard due to limitations in optical access, whereas analytical methods can be applied only for the most simple cases. On the other hand, the development of computers has promoted Dire...
Article
The present work proposes a method to study problems of drops and bubbles evolving in complex geometries. First, a conservative level set (CLS) method is enforced to handle the multiphase domain while keeping the mass conservation under control. An Arbitrary Lagrangian-Eulerian (ALE) formulation is proposed to optimize the simulation domain. Thus,...
Article
Full-text available
This paper presents a numerical study of the gravity-driven motion of single bubbles and bubble swarms through a vertical channel, using High-Performance Computing (HPC) and Direct Numerical Simulation (DNS) of the Navier-Stokes equations. A systematic study of the wall effect on the motion of single deformable bubbles is carried out for confinemen...
Article
Full-text available
A coupled Conservative Level Set – Moving Mesh – Immersed Boundary method is formulated and validated against the three-dimensional gravity-driven falling drop problem. First, by employing Conservative Level-Set (CLS) method, the multiphase domain can be successfully handled, while the mass conservation is controlled. Then, by using an Arbitrary La...
Article
Regional deposition effects are important in the pulmonary delivery of drugs intended for the topical treatment of respiratory ailments. They also play a critical role in the systemic delivery of drugs with limited lung bioavailability. In recent years, significant improvements in the quality of pulmonary imaging have taken place, however the resol...
Article
Full-text available
Suction and discharge processes with self actuated valves have a major influence in efficiency and reliability of hermetic reciprocating compressors. Understanding the operation completely in order to enhance compressor's design needs precise prediction of the fluid-structure interaction complexities involved in these processes. This paper presents...
Article
An Arbitrary Lagrangian-Eulerian formulation has been posed to solve the challenging problem of the three-dimensional Taylor bubble, within a Conservative Level Set (CLS) framework. By employing a domain optimization method (i.e. the moving mesh method), smaller domains can be used to simulate rising bubbles, thus saving computational resources. As...
Poster
Full-text available
Present research is focused on combining High-Performance Computing (HPC) and Direct Numerical Simula- tion (DNS) of gas-liquid multiphase flows, in order to study isothermal gravity-driven and thermocapillary-driven (g = 0) bubbly flows in a vertical channel. The Navier-Stokes equations and energy equation are discretized by means of the finite-vo...
Article
A complete numerical dynamic analysis of reciprocating compressor mechanism is presented, coupling the instantaneous pressure in the compression chamber, the electric motor torque and the hydrodynamic reactions, which arise from the piston and crankshaft secondary movements. Additionally, non-constant crankshaft angular velocity and the piston and...
Article
A new level-set model is proposed for simulating immiscible thermocapillary flows with variable fluid-property ratios at dynamically deformable interfaces. The Navier–Stokes equations coupled with the energy conservation equation are solved by means of a finite-volume/level-set approach, adapted to a multiple marker methodology in order to avoid th...
Article
This paper is focused on the detailed analysis of a PCM plate heat storage unit with a particular configuration, looking for the maximum contact area with the fluid (water) and the minimum volume to be used in a real household application. In that sense, a numerical study of the thermal and fluid dynamic behaviour of the water flow and the PCM melt...
Article
Full-text available
A conservative level-set model for direct simulation of two-phase flows with thermocapillary effects at dynamically deformable interface is presented. The Navier-Stokes equations coupled with the energy conservation equation are solved by means of a finite-volume/level-set method. Some numerical examples including thermocapillary motion of single a...
Conference Paper
Full-text available
This paper presents a complete numerical procedure to study the fluid-structure interaction problem of incompressible flow through reed valves, typically employed in hermetic reciprocating compressors. A partitioned semi-implicit coupling scheme is implemented, which only strongly couples the added-mass-effect (pressure term) of the fluid to the st...
Conference Paper
The present paper shows the work carried out by the authors in the FP7 EU project " Retrofitting solutions and services for the enhancement of Energy Efficiency in Public Edification (RESSEEPE) ". Different numerical simulation tools for the thermal and fluid dynamic behavior analysis of different technologies for retrofitting solutions have been d...
Article
The drain water heat recovery (DWHR) system is an interesting household technology to reduce energy costs and environmental impact. The objective of the utilisation of these devices is the recovery of the waste heat from domestic warm drain water, and transferring it to cold water entering the house. A drain water heat recovery unit has been built...
Article
Full-text available
This paper presents a methodology for simulation of two-phase flows with surface tension in the framework of unstructured meshes, which combines volume-of-fluid with level-set methods. While the volume-of-fluid transport relies on a robust and accurate polyhedral library for interface advection, surface tension force is calculated by using a level-...
Article
Full-text available
The aim of this paper is to carry out a group of numerical experiments over the fluid flow through a valve reed, using the CFD&HT code TermoFluids, an unstructured and parallel object-oriented CFD code for accurate and reliable solving of industrial flows. Turbulent flow and its solution is a very complex problem due to there is a non-lineal intera...
Article
A fixed-grid enthalpy model for unstructured meshes and explicit time integration schemes (Galione et al., 2014) is here extended for taking into account the change in density and other thermo-physical properties with the temperature and phase. Thermal expansion and contraction associated to the phase change are taken into account in the conservati...
Article
Thermocline storage concept is considered as a possible solution to reduce the cost of thermal storage in concentrated solar power (CSP) plants. Recently, a multi-layered solid-PCM (MLSPCM) concept—consisting of a thermocline-like tank combining layers of solid and phase change filler materials—has been proposed. This approach was observed to resul...
Conference Paper
Full-text available
In this work, Direct Numerical Simulations of gravity-driven motion of a swarm of bubbles in a vertical pipe are presented. These simulations were carried out in the contex of a multiple marker level-set methodology, which is integrated in a finite- volume framework on collocated unstructured grids. Each fluid particle is described by a separate le...
Article
Full-text available
The two-tank thermal energy storage (TES) system is the most used technology for storage in concentrating solar power (CSP) plants. This work focuses on a parametric study, which aims to identify the most important parameters on TES system, in order to improve the design and increase the performance of the plant. Three parameters have been consider...
Article
In the present paper, the Fractional Step method usually used in single fluid flow is here extended and applied for the two-fluid model resolution using the finite volume discretization. The use of a projection method resolution instead of the usual pressure-correction method for multi-fluid flow, successfully avoids iteration processes. On the oth...
Article
The aim of this article is to present a distributed numerical model that simulates the thermal and fluid-dynamic phenomena inside non-adiabatic capillary tubes. The resolution approach is based on a two-phase flow model where the fluid domain is discretized in a one-dimensional way, and the governing equations (continuity, momentum, and energy) are...
Article
Full-text available
A novel multiple marker level-set method is introduced for Direct Numerical Simulation of deformable fluid particles (bubbles and droplets), which is integrated in a finite-volume framework on collocated unstructured grids. Each fluid particle is described by a separate level-set function, thus, different interfaces can be solved in the same contro...
Article
Thermocline storage concept has been considered for more than a decade as a possible solution to reduce the huge cost of the storage system in concentrated solar power (CSP) plants. However, one of the drawbacks of this concept is the decrease in its performance throughout the time. The objective of this paper is to present a new thermocline-like s...
Conference Paper
Full-text available
The two-tank thermal energy storage (TES) system is the most used technology for storage in concentrating solar power (CSP) plants. Furthermore, thermocline storage concept has been considered for more than a decade as a possible solution to reduce the high cost of the storage system in these plants. In previous works, multi-layered solid-PCM (MLSP...