Guillaume Houzeaux

Guillaume Houzeaux
Barcelona Supercomputing Center · Department of Computer Applications in Science and Engineering

PhD in Science

About

235
Publications
34,581
Reads
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2,624
Citations
Citations since 2016
100 Research Items
1988 Citations
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
Introduction
I am a physicists working in High Performance Computational Mechanics at Barcelona Supercomputing Center. Together with Mariano Vázquez, I am the main architect of Alya HPC code, awarded by the International Data Corporation in 2012 (HPC Innovation Excellence Awards).
Additional affiliations
September 2005 - present
Barcelona Supercomputing Center
Position
  • Group Leader
Description
  • Main mission is to develop the multi-physics parallel simulation platform Alya. This code, part of the European PRACE benchmark suite, is an HCP-based tool adapted to run efficiently on large-scale parallel computers.
May 2002 - September 2005
CIMNE International Center for Numerical Methods in Engineering
Position
  • Senior Researcher
Description
  • CFD, numerical methods, domain decomposition methods, variaitional multiscale methods, ventilation
Education
September 1995 - May 2002
Universitat Politècnica de Catalunya
Field of study
  • Computational Fluid Dynamics
September 1993 - June 1995
Concordia University Montreal
Field of study
  • Engineering
September 1990 - May 1993
Université de Montréal
Field of study
  • Physics

Publications

Publications (235)
Article
This paper presents a load balancing strategy for reaction rate evaluation and chemistry integration in reacting flow simulations. The large disparity in scales during combustion introduces stiffness in the numerical integration of the PDEs and generates load imbalance during the parallel execution. The strategy is based on the use of the DLB libra...
Preprint
Full-text available
The complexity of combustion simulations demands the latest high-performance computing tools to accelerate its time-to-solution results. A current trend on HPC systems is the utilization of CPUs with SIMD or vector extensions to exploit data parallelism. Our work proposes a strategy to improve the automatic vectorization of finite element-based sci...
Article
In this paper, we introduce a novel parallel contact algorithm designed to run efficiently in High Performance Computing based supercomputers. Particular emphasis is put on its computational implementation in a multiphysics finite element code. The algorithm is based on the method of partial Dirichlet–Neumann boundary conditions and is capable to s...
Preprint
Full-text available
Cardiotoxicity continues to be a major health issue worldwide due to the imperative need to access new or repurposed drugs that are safe and effective. Accessibility to affordable drugs is also key to ensure access to drugs to all patients who require them. In this work we propose a workflow for an in-silico clinical trial at the 3D biventricular h...
Article
This work intends to study the effect of aortic annulus eccentricity and leaflet rigidity on the performance, thrombogenic risk and calcification risk in bioprosthetic aortic valve replacements (BAVRs). To address these questions, a two-way immersed fluid-structure interaction (FSI) computational model was implemented in a high-performance computin...
Article
With the increase in computational power in the last decade and the forthcoming Exascale supercomputers, a new horizon in computational modelling and simulation is envisioned in combustion science. Considering the multiscale and multiphysics characteristics of turbulent reacting flows, combustion simulations are considered as one of the most comput...
Article
Validating numerical models against experimental models of nasal spray deposition is challenging since many aspects must be considered. That being said, it is a critical step in the product development process of nasal spray devices. This work presents the validation process of a nasal deposition model, which demonstrates a high degree of consisten...
Preprint
Full-text available
Communities around the world are increasingly interested in nature-based solutions to mitigation of coastal risks like coastal forests, but it remains unclear how much protective benefits vegetation provides, particularly in the limit of highly energetic flows after tsunami impact. The current study, using a three-dimensional incompressible computa...
Preprint
Full-text available
In this paper, we introduce a novel parallel contact algorithm designed to run efficiently in High-Performance Computing based supercomputers. Particular emphasis is put on its computational implementation in a multiphysics finite element code. The algorithm is based on the method of partial Dirichlet-Neumann boundary conditions and is capable to s...
Article
CFD users of supercomputers usually resort to rule-of-thumb methods to select the number of subdomains (partitions) when relying on MPI-based parallelization. One common approach is to set a minimum number of elements or cells per subdomain, under which the parallel efficiency of the code is “known” to fall below a subjective level, say 80%. The si...
Article
The nasal valve is the narrowest part of the nasal airway which is responsible for the largest part of the nasal resistance. Even little changes in the aperture can affect the flow downstream through the nose significantly. Its principal function is to limit airflow for example during a rapid and short inhalation, also called a sniff. Coupling Comp...
Article
Full-text available
Numerous tsunami numerical models have been proposed, but their prediction accuracies have not been directly compared. For quantifying the modeling uncertainties, the authors statistically analyzed the prediction results submitted by participants in the tsunami blind contest held at the 17th World Conference on Earthquake Engineering. The reproduci...
Article
Full-text available
Venous-arterial extracorporeal membrane oxygenation (VA-ECMO) treatment for acute cardiogenic shock in patients who also have acute lung injury predisposes development of a serious complication called “north-south syndrome” (NSS) which causes cerebral hypoxia. NSS is poorly characterized and hemodynamic studies have focused on cerebral perfusion ig...
Preprint
Full-text available
The aim of this work was to analyze the influence of the gender and anatomical details (trabeculations and false tendons) on the electrophysiology of healthy and infarcted myocardium and their relation to the ventricular tachycardia (VT) inducibility. To this end, four anatomically normal, human, biventricular geometries (two male, two female), wit...
Preprint
Full-text available
This work introduces the first 2-way fluid-structure interaction (FSI) computational model to study the effect of aortic annulus eccentricity on the performance and thrombogenic risk of cardiac bioprostheses. The model predicts that increasing eccentricities yield lower geometric orifice areas (GOAs) and higher normalized transvalvular pressure gra...
Preprint
Full-text available
CFD users of supercomputers usually resort to rule-of-thumb methods to select the number of subdomains (partitions) when relying on MPI-based parallelization. One common approach is to set a minimum number of elements or cells per subdomain, under which the parallel efficiency of the code is "known" to fall below a subjective level, say 80%. The si...
Article
Full-text available
High fidelity simulations of expiratory events such as coughing provide the opportunity to predict the fate of the droplets from the turbulent jet cloud produced from a cough. It is well established that droplets carrying infectious pathogens with diameters of 1–5 μm remain suspended in the air for several hours and transported by the air currents...
Article
We present significant improvements and validations of a deterministic neutron transport code (NEUTRO) dedicated to solving the Boltzmann Transport Equation. The code is integrated as a module in the Alya software package developed by the Barcelona Supercomputing Center which uses the Discrete Ordinates Method on angular coordinates, multi-group fo...
Preprint
Full-text available
GPUs have climbed up to the top of supercomputer systems making life harder to many legacy scientific codes. Nowadays, many recipes are being used in such code's portability, without any clarity of which is the best option. We present a comparative analysis of the two most common approaches, CUDA and OpenACC, into the multi-physics CFD code Alya. O...
Article
Full-text available
In view of the ongoing COVID-19 pandemic and its effects on global health, understanding and accurately modelling the propagation of human biological aerosols has become crucial. Worldwide, health professionals have been one of the most affected demographics, representing approximately 20% of all cases in Spain, 10% in Italy and 4% in China and US....
Article
Full-text available
The vortex induced vibrations (VIVs) of a pivoted cylinder with finite height have been numerically investigated. A mathematical model is introduced and described, and the resulting equations are numerically solved for low Reynolds number Re = 100, 200 and several combinations of the governing parameters. Results on the solid body trajectories, the...
Article
Modeling complex material failure with competing mechanisms is a difficult task that often leads to mathematical and numerical challenges. This work contributes to the study of localized failure mechanisms by means of phase fields in a variational framework: in addition to the treatment of brittle and ductile fracture, done in previous work, we con...
Article
Full-text available
CFD has emerged as a promising diagnostic tool for clinical trials, with tremendous potential. However, for real clinical applications to be useful, overall statistical findings from large population samples (e.g., multiple cases and models) are needed. Fully resolved solutions are not a priority, but rather rapid solutions with fast turn-around ti...
Article
Animal-borne video recordings from blue whales in the open ocean show that remoras preferentially adhere to specific regions of the surface of the whale. Using empirical and computational fluid dynamics analyses, we show that remora attachment was specific to regions of separating flow and wakes caused by surface features on the whale. Adhesion at...
Article
Full-text available
Physiologically, sinus ventilation is a critical aspect of good functionality for human respiratory function, the understanding of which is still unclear. In this study we develop a method to measure sinus ventilation. Spatial and temporal features of the sinus recirculation are provided through dynamic mode decomposition (DMD). We associate the re...
Article
For complex engineering and scientific applications, Computational Fluid Dynamics (CFD) simulations require a huge amount of computational power. As such, it is of paramount importance to carefully assess the performance of CFD codes and to study them in depth for enabling optimisation and portability. In this paper, we study three complex CFD code...
Preprint
Modern supercomputers allow the simulation of complex phenomena with increased accuracy. Eventually, this requires finer geometric discretizations with larger numbers of mesh elements. In this context, and extrapolating to the Exascale paradigm, meshing operations such as generation, adaptation or partition, become a critical bottleneck within the...
Article
Multiphysics problems involve the couplings of different sets of partial differential equations. Partitioned methods consider the individual solutions of each set, which upon iterating, converge to the monolithic solution. The main drawback of partitioned methods is the additional iterative loop, which can be done a la Jacobi (parallel) or a la Gau...
Article
Full-text available
In this work we present a robust interface coupling algorithm called Compact Interface quasi-Newton (CIQN). It is designed for computationally intensive applications using an MPI multi-code partitioned scheme. The algorithm allows to reuse information from previous time steps, feature that has been previously proposed to accelerate convergence. Thr...
Article
In this work, the three-dimensional structure of the boundary layer in the context of the vortex induced vibration of a circular cylinder is presented and investigated for the first time. Large-eddy simulations of a low mass ratio ( ) two-degrees of freedom circular cylinder at the subcritical Reynolds number and zero damping ( ) for several reduc...
Article
High fidelity Computational Fluid Dynamics simulations are generally associated with large computing requirements, which are progressively acute with each new generation of supercomputers. However, significant research efforts are required to unlock the computing power of leading-edge systems, currently referred to as pre-Exascale systems, based on...
Preprint
Full-text available
In this work we present a robust interface coupling algorithm called Compact Interface quasi-Newton (CIQN). It is designed for computationally intensive applications using an MPI multi-code partitioned scheme. The algorithm allows to reuse information from previous time steps, feature that has been previously proposed to accelerate convergence. Thr...
Preprint
Full-text available
One of the main challenges of civil aviation is the construction of more efficient airplanes in terms of fuel consumption and noise emissions. Research and development on the aerodynamics of the full airplane are one of the priorities established by the Advisory Council for Aeronautics Research in Europe. In this context, high fidelity simulations...
Chapter
The flow around static and freely vibrating cylinders are of interest in understanding different phenomena encountered in many practical applications.
Chapter
The atomization process in applications of propulsion and power is commonly characterized by high pressure injections in complex geometries.
Article
Full-text available
The human heart beats as a result of multiscale nonlinear dynamics coupling subcellular to whole organ processes, achieving electrophysiologically-driven mechanical contraction. Computational cardiac modelling and simulation have achieved a great degree of maturity, both in terms of mathematical models of underlying biophysical processes and the de...
Article
Full-text available
This work presents a numerical study of a technically premixed swirling combustor with central air injection at conditions close to flashback using large-eddy simulation with flamelet modelling. This burner has the characteristics of showing flashback at low equivalence ratios, so numerical simulations are set to identify the mechanisms behind the...
Conference Paper
Full-text available
The extreme cost of massive concrete walls for the coastal protection from tsunamis is driving coastal communities around the world towards a paradigm switch in the design of their coastal stretches. Some regions of Indonesia and Chile, for example, are building coastal parks to mitigate the impact of a tsunami without drastically jeopardizing the...
Article
Accurate prediction of deformation and collapse of the upper airway during breathing is required for effective and personalised treatment of obstructive sleep apnoea (OSA). While numerical modelling techniques such as fluid-structure interaction (FSI) are promising, an outstanding challenge is to accurately predict the deformation of the airway dur...
Article
Domain decomposition (DD) is a powerful approach to numerically solve partial differential equations, and it has become popular and indispensable in simulations of fluid flows, especially those that arise from models of the real world that require large-scale, parallel computation. Domain decomposition methods (DDMs) were originally introduced for...
Chapter
This work describes the implementation of a computational system to numerically simulate the interaction between a fluid and a rigid body. This implementation was performed in a distributed memory parallelization context, which makes the process and its description especially challenging.
Article
Full-text available
Accurate prediction of deformation and collapse of the upper airway during breathing is required for effective and personalised treatment of obstructive sleep apnoea (OSA). While numerical modelling techniques such as fluid–structure interaction (FSI) are promising, an outstanding challenge is to accurately predict the deformation of the airway dur...
Poster
Full-text available
In this work we present a new coupling for the parallel code Alya designed to solve large multi-scale problems. The new code development Micropp [2] is used to solve the micro-structure and allows Alya, working in pure MPI-mode, to model the macroscale. The Micropp code is written in C++ and can be coupled with codes written in C and Fortran (like...
Article
This work studies the implementation of wall modeling for large eddy simulation in a finite element context. It provides a detailed description of how the approach used by the finite volume and finite differences communities is adapted to the finite element context. The new implementation is as simple and easy to implement as the classical finite e...
Article
Full-text available
Deposition of polydisperse particles representing nasal spray application in a human nasal cavity was performed under transient breathing profiles of sniffing, constant flow, and breath hold. The LES turbulence model was used to describe the fluid phase. Particles were introduced into the flow field with initial spray conditions, including spray co...
Article
A new model for the unresolved stresses in large-eddy simulations was recently proposed by Piomelli et al. [J Fluid Mech 2015; 766:499–527] and Rouhi et al., [Phys Rev Fluids 2016; 1(4):0444011], in which the length scale is not related to the grid size, but determined based on turbulence properties. This model, the Integral Length-Scale Approximat...
Article
The main computing phases of numerical methods for solving partial differential equations are the algebraic system assembly and the iterative solver. This work focuses on the first task, in the context of a hybrid MPI+X paradigm. The matrix assembly consists of a loop over the elements, faces, edges or nodes of the MPI partitions to compute element...
Article
Computational fluid and particle dynamics (CFPD) simulations are of paramount importance for studying and improving drug effectiveness. Computational requirements of CFPD codes demand high-performance computing (HPC) resources. For these reasons, we introduce and evaluate in this article system software techniques for improving performance and tole...
Article
The present work extends the conservative convective scheme proposed by Charnyi et al. (2017), originally formulated for mixed finite elements and tested in laminar flows, to equal order finite elements. A non-incremental fractional-step method is used to stabilise pressure, allowing the use of finite element pairs that do not satisfy the inf-sup c...
Article
Full-text available
This work investigates the accuracy and performance of a FE 2 multi-scale implementation used to predict the behavior of composite materials. The equations are formulated assuming the small deformations solid mechanics approach in non-linear material models with hardening plasticity. The uniform strain boundary conditions are applied for the macro-...
Article
The focus of this work is on the computational modeling of a pendulum made of a hyperelastic material and the corresponding experimental validation with the aim of contributing to the study of a material commonly used in seismic absorber devices. From the proposed dynamics experiment, the motion of the pendulum is recorded using a high-speed camera...