A loss-of-coolant accident(LOCA)is one of the basic design considerations for nuclear reactor safety analysis.A LOCA induces propagation of a depressurization wave in the coolant,exerting hydrodynamic forces on struct...
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A loss-of-coolant accident(LOCA)is one of the basic design considerations for nuclear reactor safety analysis.A LOCA induces propagation of a depressurization wave in the coolant,exerting hydrodynamic forces on structures viafiuid–structure interaction(FSI).The analysis of hydrodynamic forces on the core structures during a LOCA process is *** describe the implementation of a numerical strategy for prestressed *** consists of an initialization and a restarted transient analysis process,all implemented via the ANSYS Workbench by system coupling of ANSYS and *** strategy is validated by making extensive comparisons of the pressures,displacements,and strains on various locations between the simulation and reported *** approach is appealing for dynamic analysis of other prestressed structures,owing to the good popularity and acknowledgement of ANSYS and Fluent in both academia and industry.
Pressure vessel in pool layout is usually used in high power and middle pressure research reactor, Flow inversion and residual heat removal is important problem. The heat removal strategy at accident situation for a p...
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Interfacial area concentration is one of the most important parameters in two-phase flow. This parameter also reflects the interfacial area of mass, momentum and energy transfer in two-fluid model. The prediction of i...
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In this paper, we present a Q-learning algorithm for finite-horizon H∞ tracking control of unknown linear discrete-time systems. Finite horizon control is challenging due to its correspondence with a time-varying Ric...
In this paper, we present a Q-learning algorithm for finite-horizon H∞ tracking control of unknown linear discrete-time systems. Finite horizon control is challenging due to its correspondence with a time-varying Riccati equation. The proposed algorithm can determine the solution of the time-varying Riccati equation with unknown system dynamics. We first establish the time-varying Q-function, then propose a corresponding Q-learning algorithm and prove its convergence. Finally, the proposed algorithm is proved to be effective through numerical examples.
Poor interfacial adhesion of composites deriving from the surface smoothness and inertness of poly (p-phenylene benzobisoxazole) (PBO) fibers severely constrains the extensive application of the fillers. Constructing ...
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In the manufacturing process of a specific type of conical cylinder, high-frequency argon arc welding is employed for butt welding. The uncertainty of the butt weld position relative to the welding gun results in exce...
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The temperature and flow rate of coolant in the hot legs of pressurized water reactor (PWR) systems directly reflect the nuclear power and the heat transfer state of the reactor core, and are key parameters for reacto...
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The temperature and flow rate of coolant in the hot legs of pressurized water reactor (PWR) systems directly reflect the nuclear power and the heat transfer state of the reactor core, and are key parameters for reactor power control and safety protection. Most of existing studies have been conducted to analyze the steady-state thermal hydraulic features in the upper plenum and hot legs from a spatial scale, but less from a temporal scale to describe and analyze the transient features. In order to meet the requirements of key parameters measurement and safe operation, this paper established a reasonably simplified 3D geometrical model of the upper plenum and hot legs of the HPR1000 reactor based on a multi-physics field simulation platform and investigated the steady-state and transient features of the flow-thermal coupling field of coolant under numerical simulation, focusing on the coupling analysis of the flow-thermal coupling field on the spatial and temporal scales. The analysis of the steady-state features shows that the coolant flowing into the upper plenum from the upper core plate is characterized by a high middle temperature and a low peripheral temperature. As a result, there is an uneven coolant temperature distribution at the inlet of the hot legs that the temperature differences between the cold lower part and hot upper part are relatively large. However, with the axial flow of coolant, the temperature distribution in hot legs tends to be more uniform and the temperature differences decrease. The simulation results show that the flow of the low temperature coolant in hot legs dominates the change of coolant temperature distribution. The analysis of the transient features shows that a small fluctuation of flow rate at the core outlet causes changes in the turbulent kinetic energy of coolant in hot legs, but the effect on coolant temperature distribution is relatively weak. These such variations on the temporal scale can change the coupling relations of c
Electroencephalogram (EEG) equipped with high time resolution that distracted by incoherent brain sources which including ocular artifacts (OAs) generating by blinks is of great significance. Therefore, these OAs got ...
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The geometric model and the analysis model can be unified together through the isogeometric analysis method,which has potential to achieve seamless integration of CAD and *** design is a mainstream and successful meth...
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The geometric model and the analysis model can be unified together through the isogeometric analysis method,which has potential to achieve seamless integration of CAD and *** design is a mainstream and successful method in CAD *** method is not continued in simulation and optimization stage because of the model conversion in conventional optimization method based on the finite element *** integration of the parametric modeling and the structural optimization by using isogeometric analysis is a natural and interesting *** paper proposed a method to realize a structural optimization of parametric complex shapes by using isogeometric *** the given feature curves and the constraints,a feature frame model is *** on the feature frame model,a parametric representation of complex shape is *** adding some auxiliary curves,the feature frame model is divided into many box-like patches in three dimension or four-sided patches in two *** patches are built into parametric patches by using volume interpolation methods such as Coons *** on the parametric patches,isogeometic analysis is ***,the relationships are constructed among the size parameters,the control points and the physical performance *** the sensitivity matrix could be derived based on the *** size optimization is carried out in the first stage by taking the size parameters as *** on the result of size optimization,shape optimization with the constraints of stress is carried out in the second stage by taking the control points as *** planar complex shapes are taken as example to verify our *** results verify that the parametric modeling and structural optimization can be united together without model *** from this,the optimization design can be executed as a dark box operation without considering the concrete modeling and analysis by input of the sizes,constra
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