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...
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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.
Loading pattern optimization (LPO) for a PWR in nuclear power plant contains three parts: fuel assembly location optimization, burnable poison placement optimization, and used fuel assembly orientation optimization. T...
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ISBN:
(纸本)9781617820014
Loading pattern optimization (LPO) for a PWR in nuclear power plant contains three parts: fuel assembly location optimization, burnable poison placement optimization, and used fuel assembly orientation optimization. To solve the former two parts, this paper devises an innovative stochastic evolutionary algorithm - Interval Bound Algorithm (IBA), which can optimize fuel assembly location and burnable poison placement together. IBA just uses the fuel assembly's infinite multiplication factor to get rid of unfavorable patterns and to explore new promising solution space. To solve the last part, this paper applies Estimation of Distribution Algorithms (EDAs), which also belong to evolutionary algorithms. These three parts depend on each other, so it is better not to solve them separately. In order to optimize these parts in a coupled way, we use Symbiotic Co-evolutionary Algorithm (SCA) to incorporate IBA and EDAs. This technique could reflect the real optimization process. Based on these algorithms, the corresponding LPO code of IBALPO is developed. To avoid search direction to offset for inconsistency between the LP search code and the design code, IBALPO directly adopts production core design code to evaluate LPs in a parallel computation environment. Finally, this code system is used to solve a realistic reload problem to show its performance. Obtained results have illustrated that IBALPO is efficient and robust. It can find satisfying LPs in two days using 18 CPUs after evaluating about 10000 LPs for a core containing 157 assemblies.
Based on the mesoscopic finite element model of particle reinforced composites, the effects of stochastic properties of SiC particles on the ratcheting behavior of SiCP/6061Al composites were numerically analyzed by e...
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Based on the mesoscopic finite element model of particle reinforced composites, the effects of stochastic properties of SiC particles on the ratcheting behavior of SiCP/6061Al composites were numerically analyzed by employing a 3D multi-particulate unit cell and using an advanced cyclic plastic constitutive model. In the simulation, a 3D multi-particle unit cell containing the stochastic particle properties was first generated by the random sequential adsorption (RSA) method, and then the effects of the number of particles, the particle arrangement, shape, size and their stochastic distributions on the ratcheting of the composites were discussed by the numerical simulations. The results show that the smaller the particulate size and the higher the proportion of the particles distributing near the surface of matrix as well as the more the number of particulates contained in the unit cell, the higher the resistance to the ratcheting deformation. Meanwhile, the modeled composite with uniform distribution of particle size and location presents higher resistance to the ratcheting deformation than that with random distribution. The assumptions of spherical particle and its uniform distributions in size and location in the 3D unit cell can provide a reasonable simulation to the ratcheting of the particle reinforced metal matrix composites.
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...
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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.
A theoretical analysis model was developed for area contact friction pairs with different micro- Textures considering cavitation within the fluid film between two faces. Numerical simulation method was used to study t...
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The direction of each individual velocity vector is very useful information for search in Artificial Physics Optimization (APO) algorithm. APO's simple way to dealing with the errant individual exceeded the lower ...
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Although biometrics technology has progressed substantially, its performance is still to be improved for real applications. This paper aims to improve the accuracy of personal identification, when only single sample i...
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This paper introduces a new control scheme for active steering of vehicle. An ideal reference model followed by the four-wheel steering (4WS) vehicle is established resulting from the front-wheel steering (FWS) vehicl...
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ISBN:
(纸本)9781424451920
This paper introduces a new control scheme for active steering of vehicle. An ideal reference model followed by the four-wheel steering (4WS) vehicle is established resulting from the front-wheel steering (FWS) vehicle, and an H ∞ optimum controller for the 4WS vehicle is designed based on model following technology. The dynamic simulation is performed to verify control effect of the H ∞ controller, and the result shows that the H ∞ controller can apply to the 4WS vehicle system. It can not only minimize the sideslip angle of the 4WS vehicle to zero value, but also keep the yaw rate of the 4WS vehicle in accordance with the FWS vehicle. The handleability is further improved for 4WS vehicle.
This paper dissertates the function of Virtual Reality technology in the product development process, and discusses the advantage in building virtual reality designsystem with the PTC DIVISION Mockup software. The fo...
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This paper dissertates the function of Virtual Reality technology in the product development process, and discusses the advantage in building virtual reality designsystem with the PTC DIVISION Mockup software. The four keytechnology projects of building Virtual Reality designsystem are explained simultaneously. In the virtual reality environment that is built with DIVISION Mockup Software, the virtual prototype of the Tunnel Boring Machinery is established and movement simulation is completed.
Based on the present MODE-G control strategy, an improved new core control strategy is developed for the initial cycle utilizing gadolinium burnable poisons. With the relaxed axial offset control (RAOC) procedure to l...
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Based on the present MODE-G control strategy, an improved new core control strategy is developed for the initial cycle utilizing gadolinium burnable poisons. With the relaxed axial offset control (RAOC) procedure to limit the core axial offset (AO) in a band region, load follow operations are simulated under the improved core control strategy and the simulation results are compared with those obtained using MODE-G control strategy. Additionally, a preliminary evaluation of the impact of the an ejected rod with the improved core control strategy is performed. It is shown that the improved core control strategy can control the core axial power distribution more satisfactorily and effectively.
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