Results 11 to 20 of about 1,914,780 (311)

Uncertainty Analysis of Neutron Diffusion Eigenvalue Problem Based on Reduced-order Model

open access: yesYuanzineng kexue jishu, 2023
In order to improve the efficiency of core physical uncertainty analysis based on sampling statistics, the proper orthogonal decomposition (POD) and Galerkin projection method were combined to study the application feasibility of reduced-order model ...
In order to improve the efficiency of core physical uncertainty analysis based on sampling statistics, the proper orthogonal decomposition (POD) and Galerkin projection method were combined to study the application feasibility of reduced-order model based on POD-Galerkin method in core physical uncertainty analysis. The two-dimensional two group TWIGL benchmark question was taken as the research object, the key variation characteristics of the core flux distribution were extracted under the finite perturbation of the group constants of each material region, and the full-order neutron diffusion problem was projected on the variation characteristics to establish a reduced-order neutron diffusion model. The reduced-order model was used to replace the full-order model to carry out the uncertainty analysis of the group constants of the material region. The results show that the bias of the mathematical expectation of keff calculated by reduced-order and full-order models is close to 1 pcm. In addition, compared with the calculation time required for uncertainty analysis of full-order model, the analysis time of reduced-order model (including the calculation time of the full-order model required for the construction of reduced-order model) is only 11.48%, which greatly improves the efficiency of uncertainty analysis. The biases of mathematical expectation of keff calculated by reduced-order and full-order models based on Latin hypercube sampling and simple random sampling are less than 8 pcm, and under the same sample size, the bias from the Latin hypercube sampling result is smaller. From the TWIGL benchmark test results, under the same sample size, Latin hypercube sampling method is more recommended for POD-Galerkin reduced-order model.
doaj   +2 more sources

Evolve Filter Stabilization Reduced-Order Model for Stochastic Burgers Equation

open access: yesFluids, 2018
In this paper, we introduce the evolve-then-filter (EF) regularization method for reduced order modeling of convection-dominated stochastic systems. The standard Galerkin projection reduced order model (G-ROM) yield numerical oscillations in a convection-
Xuping Xie   +2 more
doaj   +2 more sources

An Artificial Compression Reduced Order Model [PDF]

open access: yesSIAM Journal on Numerical Analysis, 2020
We propose a novel artificial compression, reduced order model (AC-ROM) for the numerical simulation of viscous incompressible fluid flows. The new AC-ROM provides approximations not only for velocity, but also for pressure, which is needed to calculate forces on bodies in the flow and to connect the simulation parameters with pressure data. The new AC-
Victor P. DeCaria   +4 more
openaire   +2 more sources

Reduced-order modeling of hidden dynamics [PDF]

open access: yes2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2016
5 pages, 2 ...
Héas, Patrick, Herzet, Cédric
openaire   +3 more sources

Reduced-order modelling numerical homogenization [PDF]

open access: yesPhilosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2014
A general framework to combine numerical homogenization and reduced-order modelling techniques for partial differential equations (PDEs) with multiple scales is described. Numerical homogenization methods are usually efficient to approximate the effective solution of PDEs with multiple scales.
Abdulle Assyr, Bai Yun
openaire   +3 more sources

Experimental Study of the Transient Behavior of a Wind Turbine Wake Following Yaw Actuation

open access: yesEnergies, 2023
Wind tunnel experiments were performed to investigate the response of a wind turbine model immersed in a replicated atmospheric boundary layer to dynamic changes in the yaw angle.
Derek Micheletto   +2 more
doaj   +1 more source

Error estimation of a proper orthogonal decomposition reduced model of a permanent magnet synchronous machine [PDF]

open access: yes, 2014
Model order reduction methods, like the proper orthogonal decomposition (POD), enable to reduce dramatically the size of a finite element (FE) model.
MAC, Hung   +2 more
core   +1 more source

Verifiability of the Data-Driven Variational Multiscale Reduced Order Model

open access: yes, 2022
International audienceIn this paper, we focus on the mathematical foundations of reduced order model (ROM) closures. First, we extend the verifiability concept from large eddy simulation to the ROM setting.
Wang, Zhu   +5 more
core   +1 more source

Proper general decomposition (PGD) for the resolution of Navier–Stokes equations [PDF]

open access: yes, 2011
In this work, the PGD method will be considered for solving some problems of fluid mechanics by looking for the solution as a sum of tensor product functions. In the first stage, the equations of Stokes and Burgers will be solved. Then, we will solve the
ALLERY, Cyrille   +5 more
core   +1 more source

Proper Generalized Decomposition method for incompressible Navier–Stokes equations with a spectral discretization [PDF]

open access: yes, 2013
http://dx.doi.org/10.1016/j.amc.2013.02.022Proper Generalized Decomposition (PGD) is a method which consists in looking for the solution to a problem in a separate form.
ALLERY, Cyrille   +2 more
core   +1 more source

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