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Uncertainty Analysis of Neutron Diffusion Eigenvalue Problem Based on Reduced-order Model
Yuanzineng 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.
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Variational multiscale proper orthogonal decomposition: Navier‐stokes equations [PDF]
Numerical Methods for Partial Differential Equations, 2013 We develop a variational multiscale proper orthogonal decomposition (POD) reduced‐order model (ROM) for turbulent incompressible Navier‐Stokes equations. Under two assumptions on the underlying finite element approximation and the generation of the POD basis, the error analysis of the full discretization of the ROM is presented. All error contributions
Iliescu, Traian, Wang, Zhu
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The performance of proper orthogonal decomposition in discontinuous flows
Theoretical and Applied Mechanics Letters, 2016 In this paper, flow reconstruction accuracy and flow prediction capability of discontinuous transonic flow field by means of proper orthogonal decomposition (POD) method is studied. Although linear superposition of “high frequency waves” in different POD
Jing Li, Weiwei Zhang
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Unsteady effects at the interface between impeller-vaned diffuser in a low pressure centrifugal compressor [PDF]
INCAS Bulletin, 2013 In this paper, Proper Orthogonal Decomposition (POD) is applied to the analysis of the unsteady rotor-stator interaction in a low-pressure centrifugal compressor.
Mihai Leonida NICULESCU, Sterian DANAILA
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Mean Reattachment Length of Roof Separation Bubbles Using Proper Orthogonal Decomposition
Applied Sciences, 2023 Investigating flow separation regions on the surfaces of three-dimensional bluff bodies in turbulent flows is important because these regions can induce significant aerodynamic loads.
Hee Jung Ham +3 more
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Study on Burnup Calculation Method Based on Proper Orthogonal Decomposition Reduced-order
Yuanzineng kexue jishu, 2023 The goal of high-fidelity burnup calculations is to accurately describe the nuclide composition of the reactor over its entire lifetime. As the core physics calculation method evolves to high-fidelity, the number of burnup regions will increase thousands
ZHANG Binhang1;BI Yanzhao1;GONG Hanyuan1;ZHANG Yonghong1,*;YUAN Xianbao2
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Analysis of Multi-Stream Fuel Injector Flow Using Zonal Proper Orthogonal Decomposition
Energies, 2021 The 3-component velocity distribution of two lean-burn gas turbine fuel injectors are measured at a planar location near and parallel to the injector outlet.
Daniel Butcher, Adrian Spencer
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Spectral proper orthogonal decomposition and its relationship to dynamic mode decomposition and resolvent analysis [PDF]
, 2018 We consider the frequency domain form of proper orthogonal decomposition (POD) called spectral proper orthogonal decomposition (SPOD). Spectral POD is derived from a space-time POD problem for statistically stationary flows and leads to modes that each ...
Colonius, Tim +2 more
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Proper Orthogonal Decomposition as Surrogate Model for Aerodynamic Optimization
International Journal of Aerospace Engineering, 2016 A surrogate model based on the proper orthogonal decomposition is developed in order to enable fast and reliable evaluations of aerodynamic fields. The proposed method is applied to subsonic turbulent flows and the proper orthogonal decomposition is ...
Valentina Dolci, Renzo Arina
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Volumetric Proper Orthogonal Decomposition of an impinging jet using SPIV measurement [PDF]
MATEC Web of Conferences, 2019 Impinging jets which interact with sharp edges like slotted plates can be found in ventilation and air conditioning systems. In some cases, these configurations can be a source of desirable sounds like in musical instruments.
Hamdi Jana +8 more
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