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Numerical simulation of a UAV impacting engine fan blades

Chinese Journal of Aeronautics 2021年第10期34卷 177-190页

作者： Jingyu YU Bingjin LI Jun LIU Naidan HOU Yingchun ZHANG Yafeng WANG Yulong LI School of Aeronautics Northwestern Poly technical UniversityXi'an 710072China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China Shanghai Aircraft Airworthiness Certification Center of CAAC Shanghai 200335China China Aircraft Strength Research Institute Xi'an 710065China

A 3D digital model of a small Unmanned Aerial Vehicle(UAV)is obtained by using the method of scanning reverse modeling and joint mapping.A numerical simulation of a small UAV strikes on rotary engine blades,presented in this paper,was performed with a Transient Nonlinear Finite Element code PAM-CRASH software.A test of motor strike on plate was developed and the dynamic response of the plate were obtained to validate the numerical simulation method of a UAV strike on *** on this,dynamic damage response caused by UAV on the engine blades were *** is indicated that the impact process between the UAV and a single blade can be divided into two typical stages:cutting and *** mainly leads to the failure of the leading edge material,and impact mainly leads to the plastic deformation of the *** the same time,it is compared with the damage impacted by bird with the same *** the same mass of bird and UAV,the damage caused by UAV striking fan blade is more serious,and 1.345 kg UAV striking fan blade of typical civil aviation engine is enough to cause damage to flight safety.

关键词： Airworthiness Bird impact Engine fan blade Explicit dynamics UAV

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The precursory cooling characteristics of the reflooing in tight lattice

The precursory cooling characteristics of the reflooing in t...

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The Fifth China-Korea Workshop on Nuclear reactor Thermal Hydraulics

作者： Dan Wu Hongxing Yu Science and Technology on Reactor System Design Technology Laboratory

The advanced pressurized water reactor with a tight hexagonal lattice has its potential to improve uranium utilization. With a smaller pitch-to-diameter ratio(p/d) ranging from 1.06 to 1.20, a major problem is the emergency core cooling in a loss-of-coolant accident. The NEPTUN-III and FLORESTAN flooding experiments at PSI and KfK have been performed during the verification period 1985-1990, and the results shows that the reflooding behavior of LWHCR is quite different from that of LWR with higher peak clad temperatures and smaller quench rates. The existing system codes like RELAP5, CATHARE, TRAC may not be able to be used in the calculations of the reflooding phase of LWHCR. Though some efforts have been put into the validation of the improvement of codes, the results are not so good. In this study, the characteristics of the reflooding behavior of tight lattice are pointed out, and the deficiencies of the reflooding models of RELAP5/MOD3 are also fount out after a simulation of the NEPTUN-III reflooding test. The precursory cooling in tight lattice is not effective especially at low reflooding rates (<4cm/s), the droplet enhancement is not significant compared to LWR, and the vapor Reynolds number is much smaller. Finally, a few modifications to RELAP5/MOD3 are made. Compared with the original code, the modified one can better predict the reflooding phase of tight lattice especially the peak clad temperatures at low reflooding rates. More work should be done to deal with the heat transfer characteristics in the transition region of reflooding in tight lattice..

关键词： reflood tight lattice RELAP5 precursory cooling

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Thermal hydraulic analysis on the success criteria of steam generator tube rupture accident 23

Thermal hydraulic analysis on the success criteria of steam ...

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23rd International Conference on Nuclear Engineering: Nuclear Power - Reliable Global Energy, ICONE 2015

作者： Ran, Fu Dan, Wu Ding, Shuhua Qian, Peng Libo, Qian Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu Sichuan China Nuclear Power Institute of China Chengdu Sichuan China

ISBN: (纸本)9784888982566

The SGTR studies correspond to the double-ended guillotine rupture of a steam generator tube, which allows unimped blowdown from both ends of the severed tube. Occurrence of the SGTR a ccident leads to an inc rease in contamination of t he secondary system as well as activ ity release to atmosphe re due to leakage of radioactive coolant from the RCS. The refore the au tomatic or operator actions should be taken in tim e to terminate the leakage. For ACP1000, the ti me window of the operator action is prolonged by adding new protection signals and equipment. In present work, the maximal time interval of th e operator action after t he SGTR is studied with these new m easures. And after the operator takes actions, in accordance with the procedure, no SG overflow takes place till the pressure of the primary side is equal to that of the secondary side. Copyright © 2015 by JSME.

关键词： Nuclear fuels

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Research on heat removal capability of secondary passive residual heat removal system for small modular reactor 17

Research on heat removal capability of secondary passive res...

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17th International Topical Meeting on Nuclear reactor Thermal Hydraulics, NURETH 2017

作者： Zhang, Dan Ran, Xu Zhou, Ke Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Xiehe Community ShuangLiu County Changshun Road No.328 Chengdu China

The transient performance of the Secondary Passive Residual Heat Removal system (SPRHR) for a small modular PWR was studied, the study focused on the thermal hydraulic characteristics at different initial water inventory in natural circulation loop of SPRHR. The result shows that, for SPRHR of SMR, after the short term of reactor scram, the small water inventory could maintain the two phase heat transfer state in the secondary side of Once-Through Steam Generator and the first side of emergency condenser, which will strengthen the heat transfer in SPRHR. However, for long time’s operation such as 72h, the water make up to the SPRHR should be considered as defense in depth for potential water leakage from system in accident situation. © 2016 Association for Computing Machinery Inc. All Rights Reserved.

关键词： Hydraulics

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Research on model validation of routing protocol for UAV swarm cooperative disaster relief system

Research on model validation of routing protocol for UAV swa...

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2023 International Conference on Computer Application and Information Security, ICCAIS 2023

作者： Wei, Tonghao Liu, Jie Yang, Fei Han, Wenxing Jiang, Wei School of Computer Science/Software University of South China Hunan Hengyang China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Sichuan Chengdu China

ISBN: (纸本)9781510675032

In recent years, with the continuous expansion of unmanned aerial vehicle (UAV) swarm applications and the rapid development of the UAV self-organizing network system, the related security threats have also increased. In this paper, we conduct the communication model of the UAV swarm cooperative disaster relief system by verifying the security attributes of the UAV swarm cooperative disaster relief system based on the dynamic source routing (DSR) protocol and we also analyze and verify their security attributes. Finally, we propose a novel scheme to model, characterize, and verify the security attributes of the UAV swarm communication networks. It provides a formal analysis and verification method for verifying the security attributes of self-organized network systems, simplifying a series of challenging verification processes that come with demonstrating the security attributes of the system through simulation experiments. © 2024 SPIE.

关键词： Formal verification

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A High Efficiency and Precision Interpolation Method for searching Fluid Field Information around Droplets in Sparse Two-phase Flow 17

A High Efficiency and Precision Interpolation Method for sea...

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17th International Topical Meeting on Nuclear reactor Thermal Hydraulics, NURETH 2017

作者： Zhao, Fulong A. Bo, Hanliang B. Zhou, Ya C. Liu, Ying D. Institute of Nuclear and New Energy Technology Tsinghua University Beijing100084 China Science and Technology on Reactor System Design Technology Laboratory Nuclear PowerInstitute of China Chengdu610041 China

In the nuclear power station, the steam-water separator is a crucial appliance, a sequence of droplet lifecycle phenomena take place, including the droplet formation, droplet motion in the steam space, the mutual collisions between droplets, droplet extinction and the phase transformation. Together with the entraining steam, the droplets experiencing above complex processes consist a typical sparse two-phase flow, which can be well investigated by the Euler-Lagrange approach in terms of numerical simulations. With the Euler-Lagrange method, the microscopic behavior of the droplets and the steam-water separating mechanism are promising to be captured. When applying the Euler-Lagrange approach to simulate the droplets motion in the fluid field, one should first obtain the fluid parameters surrounding the droplets by the interpolation method, which may significantly influence the efficiency and precision of subsequent simulation results. In the present work, we examined the performance of four different interpolation schemes in the simulation of the droplet-steam flow inside the steam-water separator, including the k-d tree and the brute force search algorithm, the nearest point and 4-point interpolation method, and the boundary layer meshes refinement and total mesh refinement method. The computational efficiency and precision of the four methods were studied in comparison. The nearest point interpolation scheme takes less computing time, whereas with lower accuracy. Therefore, the sufficiently fine meshes are necessary to improve the calculation accuracy, which in turn lead to the reduced computational efficiency. The accuracy of the four-points interpolation scheme is remarkably higher than that of the nearest point interpolation scheme at the cost of much more (more than 2 folds) CPU time. To make a trade-off between the efficiency and precision, a high efficiency and precision interpolation method is put forward by combining the nearest point interpolation scheme

关键词： Mesh generation

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Preliminary analysis of core heat-up for ATFs under accident conditions

Preliminary analysis of core heat-up for ATFs under accident...

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Top Fuel 2016: LWR Fuels with Enhanced Safety and Performance

作者： Li, Wei Chen, Ping Su, Guanghui Qiu, Suizheng Tian, Wenxi Li, Wenjie School of Nuclear Science and Technology Xi'an Jiaotong University Xi'an Shaanxi710049 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu Sichuan610213 China

ISBN: (纸本)9780894487309

Experience gained in decades of nuclear safety research and previous nuclear accidents direct to the investigation of passive safety system design and accident-tolerant fuel (ATF) system which is now becoming a hot research point in the nuclear energy field. The ATF system is aim at upgrading safety characteristics of the nuclear fuel and cladding in a reactor core where active cooling has been lost, and is preferable or comparable to the conventional UO2-Zr fuel system when the reactor is in normal operation. By virtue of advanced materials with improved basic properties and oxidation resistance, the ATF system is placed high hopes on slowing down the accident progression, allowing wider margin of time for the mitigation measures to be effective. SiC and FeCrAl accident-tolerant claddings and FCM accident-tolerant fuel are considered in this work, as they are receiving more and more attention in China. In this paper, the improved performance of UO2-SiC, UO2-FeCrAl, FCM-SiC and FCM-FeCrAl fuel systems on the core heat-up progress in a pressurized water reactor (PWR) is analyzed by using the best-estimate system code RELAP5 and severe accident analysis program respectively. For this purpose two accident scenarios are selected, e.g., a large break LOCA as a design base accident and an extended station blackout (SBO) severe accident, to reflect the accident-tolerance characteristic of ATFs. Obtained quantitative results show promising safety enhancement in terms of peak cladding temperature (PCT) and recovery of the core coolability for the selected ATF systems, which is beneficial for further down-selections of various kinds of ATF systems.

关键词： Silicon carbide

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The friction characteristics and velocity distribution of pulsatile flows in a rod bundle 27

The friction characteristics and velocity distribution of pu...

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27th International Conference on Nuclear Engineering: Nuclear Power Saves the World!, ICONE 2019

作者： Li, Xing Qi, Peiyao Tan, Sichao Mi, Zhengpeng Li, Dongyang Fundamental Science on Nuclear Safety and Simulation Technology Laboratory Harbin Engineering University Harbin Heilongjiang China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China

ISBN: (纸本)9784888983051

The transient fluctuation of flow rate in a nuclear reactor is a common phenomenon in floating reactors and possible accident scenarios, the response for transient flow determined the damage threshold of fuel assemblies. Friction characteristics and velocity distribution of low-frequency pulsatile flows in a rod bundle have been studied. The experiments were conducted under the time-averaged Reynolds number 1000 Copyright © 2018-2019 by JSME

关键词： Pressure drop

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Effect of He/dpa ratio on bubble characteristics in Fe9Cr1.5W0.4Si F/M steel during irradiation and annealing

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Journal of Materials science & technology 2024年第30期197卷 17-24页

作者： Dewang Cui Kefei Pei Ziqi Cao Yipeng Li Yifan Ding Yuanming Li Shichao Liu Guang Ran College of Energy Xiamen UniversityXiamen361102China Science and Technology on Reactor System Design Technology Laboratory Chengdu610213China College of Chemistry and Chemical Engineering Xiamen UniversityXiamen361005China Fujian Provincial Nuclear Energy Engineering Technology Research Center Xiamen361102China Nuclear Power Institute of China Chengdu610213China

The He production rate(i.e.,He/dpa)in nuclear reactors strongly affects the degradation of material *** is an important but not yet fully understood ***,the effect of He/dpa on bubble char-acteristics in Fe9Cr1.5W0.4Si ferrite-martensitic(F/M)steel was in situ studied during 400 keV Fe^(+)and 30 keV He^(+)dual-beam irradiation at 723 K with three ratios of 100,500,and 2500 appm He/dpa and subsequent stepwise annealing using transmission electron microscopy(TEM).He/dpa strongly affected the bubble *** irradiation,the higher the He/dpa,the smaller the size of irradiated bubbles,but the higher their ***,He/dpa didn’t affect the final saturation size of irradiated bubbles for all three cases,which was-2.2 *** annealing,high He/dpa caused large,immobile,dense polyhedral bubbles with a wider bubble size distribution,while low He/dpa caused small,low-mobility,and relatively low-density spherical *** was found that the higher the He/dpa ratio,the greater the swelling during irradiation and annealing,and annealing further enhanced the ***,the tunnel structure was first found in body-centered cubic(BCC)F/M steel during in-situ *** current work provides valuable and potential insights for further understanding the He/dpa effects in materials serving in different nuclear reactors.

关键词： He effect Ferritic-martensitic steel He bubble Ion irradiation Annealing

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Experimental and Numerical Research on Droplet Drag Coefficient and Deformation Coefficient in Nuclear Power Plants 29

Experimental and Numerical Research on Droplet Drag Coeffici...

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2022 29th International Conference on Nuclear Engineering, ICONE 2022

作者： Ru, Li Ruifeng, Tian Bowen, Chen Bo, Wang Harbin Engineering University Heilongjiang Provincial Key Laboratory of Nuclear Power System & Equipment Harbin China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China

ISBN: (纸本)9780791886502

There are many multiphase flow phenomena in steam generators (SG) of nuclear power plants (NPPs) and the movement of droplets affects the separation efficiency of dryers in SG. And the most important factor affecting droplet movement is drag force on droplet. Drag force coefficient (DRC) and deformation coefficient (DEC) as characterization coefficient of drag force have important research significance. In this paper, water and silicone oil are used as continuous phase and dispersed phase, respectively. Study on variation of the DRC when Re is in the range of 30-1200 is carried out. Firstly, the motion of droplets (MDs) of different sizes is visually studied by using the high-speed camera and images of MD is acquired. The droplet contour is recognized based on principle of boundary differentiation and the centroid coordinates of the droplet are determined, thus DRC and DEC are obtained. Besides, the relationship between DRC and DEC are researched. Additionally, Lattice Boltzmann Method (LBM) is used to simulate the droplet motion. The simulation results are compared with the experimental results, thus verifying the feasibility of LBM method to simulate the MD. The results show that when velocity of droplet (VD) is low, DRC is inversely proportional to VD. While VD is high, DRC is constant. When the droplet diameter (DD) is small, the final VD is proportional to DD, and when DD is large, the final VD is proportional to the square of DD. The DEC is linearly related to We. The larger the We, the smaller the DEC. Shan-Chen model of LBM is feasible for droplets with low Reynolds number (Re), while the simulation of droplets with high Re is the future prospect. © 2022 by ASME.

关键词： Numerical methods

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