Among the existing CHF models, the bubble crowding model and the liquid sublayer dryout model have been well accepted for subcooled flow boiling. But both of the two models couldn't give explanation about some det...
详细信息
Without considering the echo signal power changes caused by target distance changes during the accumulated time the traditional radar equation is hardly applied. We take account of the effects of velocity, signal-to-n...
详细信息
Without considering the echo signal power changes caused by target distance changes during the accumulated time the traditional radar equation is hardly applied. We take account of the effects of velocity, signal-to-noise ratio during the processing time; a modified radar equation is built which can be used for long-time integration of weak targets with high speed. After analyzing the relation between detection range and target velocity, integration time with processing time, we draw the constraint conditions and the corresponding conclusions.
In this paper, the flow oscillation in the parallel multichannel system has been studied under ocean condition with RELAP5/MC. A double-channel boiling system model is built using the code RELAP5/MC and it is proved t...
详细信息
In this study, tensile test and Charpy impact test of domestic A508-III steel are carried out in the ductile-brittle transition range, in which obtained the mechanical properties and temperature dependence of Charpy i...
详细信息
In this study, tensile test and Charpy impact test of domestic A508-III steel are carried out in the ductile-brittle transition range, in which obtained the mechanical properties and temperature dependence of Charpy impact energy. Fracture toughness test temperature is determined through the correlation with characteristic temperature, at which Charpy impact energy is 28 J or 41 J. The Master Curve of 12.7 mm SE(B) is respectively from the single-temperature and multi-temperature method, and measured T0 was valid. The result shows that the reference temperature T0 derived from two methodsis basically consistent. And the reference temperature T0 of domestic A508-III steel is about -63°C.
In order to verify the correctness of PLC programs by formal methods, the definition of denotational semantics on PLC program language was studied to achieve PLC programs modeling and model checking. Based on the exte...
详细信息
In order to verify the correctness of PLC programs by formal methods, the definition of denotational semantics on PLC program language was studied to achieve PLC programs modeling and model checking. Based on the extended λ-calculus definition, the configuration of PLC program architecture, denotational semantics of PLC programs and functions of denotational semantics were defined, which proves the basis of model checking and theorem.
The determination of crack-opening-area (COA) is very important in the application of LBB technique. A numerical method based on coupled finite element-meshless Galerkin method (FEM/EFG) is proposed to calculate the c...
详细信息
This paper establishes a nodal method to solve the two coupled equations transformed from the transport equation by SP3 method. In the nodal method, diffusion equation is discretized into average fluxes in the nodes a...
详细信息
This paper establishes a nodal method to solve the two coupled equations transformed from the transport equation by SP3 method. In the nodal method, diffusion equation is discretized into average fluxes in the nodes and partial currents on the nodal boundaries. Nodal response relationship is obtained by expanding the detailed nodal flux into a sum of exponential functions. Numerical results demonstrates that the nodal SP3 method can treat polygonal meshes in different shapes with good parallel property, and that it can provide a similar accuracy while runs about six times faster than the nodal-SN (N=4) method DNTR under the same mesh.
We combined the subgroup method and the method of characteristics for neutron resonance self-shielding calculation, and programmed a resonance calculation code SGMOC. This code is based on the WIMSD format multi-group...
详细信息
We combined the subgroup method and the method of characteristics for neutron resonance self-shielding calculation, and programmed a resonance calculation code SGMOC. This code is based on the WIMSD format multi-group data library. The numerical results of SGMOC are in good agreement with those of MCNP, and thus SGMOC has high calculation precision and geometry flexibility. Based on the SGMOC code, we studied two modification methods for the resonance interference effect calculation. The conditional probability method had a correction effect about 30~180 pcm for kinf calculation of UO2 fuel cell. The method by virtue of NJOY code had a correction effect about 20~130 pcm for kinf calculation of UO2 fuel cell.
Based on generalized coarse mesh rebalance (GCMR) method, this paper proposes a new acceleration method for the method of characteristics (MOC) in unstructured meshes: the generalized coarse-mesh finite difference (GC...
详细信息
ISBN:
(纸本)9781617820014
Based on generalized coarse mesh rebalance (GCMR) method, this paper proposes a new acceleration method for the method of characteristics (MOC) in unstructured meshes: the generalized coarse-mesh finite difference (GCMFD) method. The GCMFD method, which applies equivalent width of coarse mesh to establish the finite difference discretization, can use unstructured coarse meshes composed of adjacent fine meshes to speed up the MOC iteration. The convergence property of the GCMFD method is controlled by width factor. However, the optimal width factor cannot be given a priori. Method of adjusting width factor automatically is proposed in this paper. Finally, the GCMFD method is adopted in the 3-D neutron transport MOC code TCM. Numerical tests show that the GCMFD, using generalized-geometry coarse meshes, can accelerate the MOC iteration with good speedup.
At present, the information and control system (I&C) and operation support system (OSS) of the nuclear power plants (NPPs) are designed separately;their structures and functions are independent. So, the compatibil...
详细信息
暂无评论