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Coupled Axisymmetric Peridynamics with Stabilized Correspondence Material Model for Ablation and Fracture Problems

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SSRN 2024年

作者： Zhang, Hanbo Liu, Zhenhai Li, Chengxuan Ye, Hongfei Zhang, Hongwu Li, Hui Zheng, Yonggang State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial Equipment Department of Engineering Mechanics School of Mechanics and Aerospace Engineering Dalian University of Technology Dalian116024 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610200 China

A coupled axisymmetric peridynamics with a stabilized correspondence material model (CA-PD-SCMM) is proposed in this work to effectively simulate the ablation and ductile fracture behaviors of metals under high temperatures. To quantify the damage resulting from compression and shearing deformations, a strain energy density decomposition method is incorporated into the ductile damage model. Furthermore, a novel axisymmetric stabilization method based on peridynamics linearization theory is introduced to mitigate numerical oscillations arising from zero-energy modes in both thermal and mechanical scenarios. To capture the varying geometries and update the boundary conditions during ablation, a moving boundary model is developed based on temperature-associated criteria. To validate the capacity of the proposed CA-PD-SCMM, several representative numerical experiments are conducted. These examples not only affirm its ability to stabilize numerical oscillations in coupled axisymmetric thermoplastic problems but also demonstrate its capability for accurately simulating ablation and predicting crack propagation. © 2024, The Authors. All rights reserved.

关键词： Ductile fracture

Research on Optimization of Momentum Source Model to Supercritical Carbon Dioxide Flow in Wire Wrapped Rods Bundle

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SSRN 2023年

作者： Liu, Sichao Liu, Yu Yang, Xiaolei Li, Xiaochang Tian, Ruifeng College of Nuclear Science and Technology Harbin Engineering University Harbin150001 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu601213 China College of Aerospace and Civil Engineering Harbin Engineering University Harbin150001 China

Wrapped wire is widely used in new reactor core design. Simulation with traditional body fitted grid needs a large number of grids, which requires more computing resources. By optimizing the basic mathematical model of momentum source method, simulation of wire wrapped rod bundle with arbitrary wire shape can be carried out. By simulating the experimental data of 3 wire wrapped rod bundle, the model adaptability of momentum source method and mesh sensitivity analysis are carried out. Then optimized momentum source method and original momentum source method are compared based on simulation of supercritical carbon dioxide flow and heat transfer in wire wrapped rod bundle with different wire shapes. Through comparison with body fitted grid, the improvement of accuracy of optimized momentum source model can be proved. In conclusion, optimized momentum source method can greatly save the computational resources and calculated results is more accurate than original momentum source method. © 2023, The Authors. All rights reserved.

关键词： Wire

Theoretical research on two-phase flow instability in parallel rectangular channels under periodic perturbation

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Theoretical research on two-phase flow instability in parall...

2020 International Conference on Nuclear Engineering, ICONE 2020, collocated with the ASME 2020 Power Conference

作者： Qian, Libo Deng, Jian Huang, Tao Cai, Rong Science and Technology on Reactor System Design Technology Laboratory Npic Chengdu Sichuan China

ISBN: (纸本)9780791883785

A theoretical model for Density Wave Oscillations (DWOs) flow instability in parallel rectangular channels under periodic heaving motion is established with a lumped mathematical model based on homogenous hypothesis. The parallel rectangular channels comprise of the entrance section, the heating section, the riser section and the upper- and lower plenums, which guarantee the isobaric pressure drop condition between channels and the model consists of boiling channel model, pressure drop model, parallel channel model, additional pressure drop model generated by heaving motions, the constitutive and numerical models. The effect of periodic perturbation is introduced through additional pressure drop in the momentum equation. The model is validated with experimental data of a twin-rectangular-channel flow instability experiment under static condition. Then the flow instability in parallel-rectangular-channel system is studied under periodic perturbation and the margin of flow instability and the threshold power of the system under static condition is calculated as basis condition for comparison. The effect of the amplitude and period of perturbation is analyzed analytically and the results show that the amplitude and period of perturbation shows little effect on flow instability. While when the additional pressure difference introduced by heaving motion is comparable with that under static condition, the effect of amplitude becomes stronger. And the period of perturbation strongly effects the threshold power when it is identical to that of natural period of the system, which can be explained by resonance between the perturbation and the system. And this effect is even stronger when the asymmetric heating condition is introduced. © 2020 American Society of Mechanical Engineers (ASME). All rights reserved.

关键词： Pressure drop

Experimental study on the sub-channel void fraction characteristics of bubbly flow in rod bundles

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Experimental study on the sub-channel void fraction characte...

2020 International Conference on Nuclear Engineering, ICONE 2020, collocated with the ASME 2020 Power Conference

作者： Ren, Quan-Yao Pu, Zeng-Ping Zheng, Mei-Yin Su, Min Chen, Ping Pan, Liang-Ming He, Hui He, Qing-Che Science and Technology on Reactor System Design Technology Laboratory Chengdu China Chongqing China

ISBN: (纸本)9780791883785

The gas-liquid two-phase flow behaviors are always associated with its dynamic void fraction, such as flow resistance, heat transfer coefficient, phase distribution, critical heat flux etc. As regard to the commercial PWR and BWR, rod bundles are the typical geometry, which contains many subchannels for coolant flowing. In present study, the sub-channel void fraction was measured in 5×5 rod bundles with the subchannel impedance void meter consisting of 12 strip electrodes. Based on the measured void fraction in different sub-channels, the void fraction dynamics, PDF (probability distribution function) and CDF (cumulative distribution function) curves were analyzed to make clear the effect of superficial gas and liquid velocity, flow development and casing tube. The empirical correlation for PDF of dynamic sub-channel void fraction has been developed, which showed good fitness with PDF and CDF curves and satisfying accuracy of averaged void fraction. © 2020 American Society of Mechanical Engineers (ASME). All rights reserved.

关键词： Void fraction

Dynamic Rod Worth Estimation with Extended Kalman Filter and Background Current Elimination

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Dynamic Rod Worth Estimation with Extended Kalman Filter and...

第40届中国控制会议

作者： Hao Xia Junqi Yang Chao Bao Dalian University of Technology Science and Technology on Reactor System Design Technology Laboratory

The dynamical rod worth method(DRWM) is a fast and accurate method to measure and validate the worth of control rod during the zero power physics test at pressure water nuclear *** control rod worth is obtained from the reactivity change caused by the fast insertion of the control rod into the bottom of the *** reactivity is calculated based the measured ex-core detector signals which normally varies from～10 nA to～10 nA during the rod insertion *** the later stage of the test,as the detector signal becomes～10 nA,the impact of the measurement noise and the gamma-ray background current on the reactivity calculation becomes *** this paper,we developed an extended Kalman filter(EKF) with suitable weighing matrices to filter out the measurement *** most measurement noise filtered out,a background current estimation method is used to eliminate the effect of the background *** combining the background current estimation method with EKF filter,accurate control rod worth is obtained from the real test data.

关键词： Dynamic Rod Worth Method Reactivity Extended Kalman filter Background Current

Insights into Dissolved Oxygen Dependent Crack Initiation Mechanism of 316ln Stainless Steel Fatigue Tested in High-Temperature Pressurized Water

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SSRN 2024年

作者： Qiao, Yufei Li, Hui Tan, Jibo Liu, Daoping Zhang, Ziyu Wu, Xinqiang Ke, Wei CAS Key Laboratory of Nuclear Materials and Safety Assessment Liaoning Key Laboratory for Safety and Assessment Technique of Nuclear Materials Institute of Metal Research Chinese Academy of Sciences Shenyang110016 China School of Materials Science and Engineering University of Science and Technology of China Hefei230026 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China China

The corrosion fatigue behavior of 316LN SS hollow specimen was investigated in high-temperature pressurized water at different dissolved oxygen (DO) concentrations ( © 2024, The Authors. All rights reserved.

关键词： Corrosion fatigue

Development, Validation and Application of Sub-Channel Thermal-Hydraulic Analysis Code for Liquid Metal Cooled reactor

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SSRN 2024年

作者： Wang, Jinshun Chen, Ronghua Liang, Yu Gui, Minyang Zhu, Xinyang Tian, Wenxi Qiu, Suizheng Su, Guanghui School of Nuclear Science and Technology Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Nuclear Power Institute of China 328 Changshun Avenue Chengdu610213 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China College of Nuclear Science and Technology Harbin Engineering University Harbin150001 China

The liquid metal reactor, specifically the lead-based fast reactor and the sodium-cooled fast reactor, are generally recognized as the most significant representatives of the Gen IV reactors due to their sustainability, economy, security and reliability. In order to conduct thermal-hydraulic safety analysis for liquid metal cooled fast reactors, adaptive improvements are made to the model and solution algorithms based on the sub-channel analysis method, and a Sub-channel Analysis Code Of Safety for Liquid Metal cooled reactor (SACOS-LMR) is developed. The validation of SACOS-LMR is conducted using classic experimental data of liquid metal. The results show that the dimensionless temperature deviations of ORNL 19-pin test and Toshiba 37-pin test are within 10%, and the relative temperature deviations of KIT-KALLA 19-pin test are within 25%. These findings confirm the accuracy and reliability of SACOS-LMR in predicting the temperature distribution of liquid metal reactors. Ultimately, calculations conducted on the ALFRED lead-cooled fast reactor demonstrated the practical utility of the code and have certain guiding significance for its subsequent design and development. © 2024, The Authors. All rights reserved.

关键词： Liquid metals

Numerical Study on Benchmark Analysis of NACIE-UP Facility with Uniform and Non-Uniform Power Distribution

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SSRN 2024年

作者： Li, Haoyang Zhang, Dalin Zhou, Lei Deng, Jian Tian, Wenxi Su, Guanghui Qiu, Suizheng State Key Laboratory of Multiphase Flow in Power Engineering Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology School of Nuclear Science and Technology Xi’an Jiaotong University Xi’an710049 China Nuclear Power Institute of China 328 Changshun Avenue Chengdu610213 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China

The NACIE-UP facility is located at the ENEA Brasimone Research Centre and is designed to investigate the thermo-hydraulic properties of LBE within a wire-spaced assembly under uniform and non-uniform power distribution conditions. In this study, the thermo-hydraulic characteristics of FPS are analyzed. ANSYS Fluent solver is applied with the COUPLE algorithm of RANS [[EQUATION]] model. Cheng&Tak correlation and computational conditions are implanted into Fluent in the form of UDFs. The results show that the RMSEs of ADP10SS1 and ADP10SS2 are 2.52 K and 3.69 K, 7.05 K and 8.48 K for ADP06SS1 and ADP06SS2, respectively, which indicate that the adopted models have good prediction ability for the temperature of the experimental conditions. Meanwhile, the heat transfer characteristics are investigated and compared with the correlations of Ushakov, Mikityuk, Kazimi and Carelli. Above all, this study provides quantitative and qualitative analysis for verification and validation of CFD/STH code and stand-alone CFD simulation. © 2024, The Authors. All rights reserved.

关键词： Heat transfer

Optimization design of the reactor coolant pump flywheel comprised of multi-ring packing heavy metal alloy 9

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Optimization design of the reactor coolant pump flywheel com...

9th Global Conference on Materials science and Engineering, CMSE 2020

作者： Jiang, L. Wu, C.W. Shao, X.J. Zhang, Y. Yu, M.D. National Key Laboratory of Science and Technology on Reactor System Design Technology Nuclear Power Institute of China Chengdu610041 China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian116024 China

To improve energy storage performance of the multi-ring RCP flywheel comprised of inner hub, tungsten alloy ring and outer retainer, optimization design process for the radial thicknesses of components and interference fit assembly is demonstrated. Radial thicknesses of these components and magnitude of interference fit are set as design parameters to construct parametric analysis model. design of experiments (DOE) technique is adopted to generate design matrix for sensitive analysis. Subsequently, radial basis function (RBF) approximation is employed to search for the optimal design considering structural integrity requirement. Finally, a proper range of the magnitude of interference fit is obtained which can not only prevent neither slippage nor separation between the inner hub and tungsten alloy ring but also ensure the safety of structural strength. In addition, it is found that to ensure a high moment of inertia and energy density, a reasonable large radial thickness of tungsten alloy ring and a reasonable small radial thickness of outer retainer are required. © Published under licence by IOP Publishing Ltd.

关键词： Heavy metals