arXiv subjects

Michel Rasquin

Publications and source records attributed to Michel Rasquin.

5 recordsLinked to original sources

arXiv2025

A hybrid framework integrating classical computers and quantum annealers for optimisation of truss structures

This work proposes a hybrid framework combining classical computers with quantum annealers for structural optimisation. At each optimisation iteration of an iterative process, two minimisation problems are formulated one for the underlying mechanical boundary value problem through the minimisation potential energy principle and one for the minimisation problem to update the design variables. Our hybrid approach leverages the strength of quantum computing to solve these two minimisation problems at each step, thanks to the developed quantum annealing-assisted sequential programming strategy introduced in [Nguyen, Wu, Remacle, and Noels. A quantum annealing-sequential quadratic programming assisted finite element simulation for non-linear and history-dependent mechanical problems. European Journal of Mechanics-A/Solids 105 (2024): 105254]. The applicability of the proposed framework is demonstrated through several case studies of truss optimisation, highlighting its capability to perform optimisation with quantum computers. The proposed framework offers a promising direction for future structural optimisation applications, particularly in scenarios where the quantum computer could resolve the size limitations of the classical computers due to problem complexities.

cs.CE↗

arXiv2025

Turbulent Injection assisted by Diffusion Models for Scale Resolving Simulations

The present research proposes a new memory-efficient method using diffusion models to inject turbulent inflow conditions into Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS) for various flow problems. A guided diffusion model was trained on Decaying Homogeneous Isotropic Turbulence (DHIT) samples, characterized by different turbulent kinetic energy levels and integral length scales. Samples generated by the diffusion model accurately reproduce turbulence statistics, such as the energy spectrum and the two-point autocorrelation functions, while preserving the ability to generate instantaneous three-dimensional velocity fields with detailed fluctuations. Physical representativeness is also evaluated by injecting the \textit{synthetic} samples into a free domain (i.e., without any wall boundary) through an inlet boundary condition. The method demonstrates promising results regarding energy spectrum, spatial correlation, turbulent kinetic energy level, and integral length scales without increasing the development distance as compared to a library-based method. The following article has been submitted to/accepted by Physics of Fluid (AIP Publishing LLC). After publication, it will be available https://doi.org/10.1063/5.0278541.

physics.flu-dyn↗

arXiv2014

Boundary Layer Adaptivity For Incompressible Turbulent Flows

Boundary layers in turbulent flows require fine grid spacings near the walls which depend on the choice of turbulence model. To satisfy these requirements a semi-structured mesh is generally used in this area with orthogonal and layered elements. Adaptation of such a mesh needs to take into account the flow physics along with the standard error indicator approach. In this paper a novel methodology which combines Hessian based error indicators with flow physics to drive mesh adaptation is illustrated. Particular focus is on the thickness adaptation of the layered mesh. The technique is applied to two turbulent incompressible flow cases and its effectiveness is studied.

physics.flu-dyn↗

arXiv2014

Anisotropic Boundary Layer Adaptivity of Multi-Element Wings

Multi-element wings are popular in the aerospace community due to their high lift performance. Turbulent flow simulations of these configurations require very fine mesh spacings especially near the walls, thereby making use of a boundary layer mesh necessary. However, it is difficult to accurately determine the required mesh resolution a priori to the simulations. In this paper we use an anisotropic adaptive meshing approach including adaptive control of elements in the boundary layers and study its effectiveness for two multi-element wing configurations. The results are compared with experimental data as well as nested refinements to show the efficiency of adaptivity driven by error indicators, where superior resolution in wakes and near the tip region through adaptivity are highlighted.

physics.flu-dyn↗

arXiv2014

Finite Element Flow Simulations of the EUROLIFT DLR-F11 High Lift Configuration

This paper presents flow simulation results of the EUROLIFT DLR-F11 multi-element wing configuration, obtained with a highly scalable finite element solver, PHASTA. This work was accomplished as a part of the 2nd high lift prediction workshop. In-house meshes were constructed with increasing mesh density for analysis. A solution adaptive approach was used as an alternative and its effectiveness was studied by comparing its results with the ones obtained with other meshes. Comparisons between the numerical solution obtained with unsteady RANS turbulence model and available experimental results are provided for verification and discussion. Based on the observations, future direction for adaptive research and simulations with higher fidelity turbulence models is outlined.

physics.flu-dyn↗