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NUMERICAL SIMULATION AND EXPERIMENTAL RESEARCH OF SHEAR-DRIVEN WATER FILM ON FLAT PLATE

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NUMERICAL SIMULATION AND EXPERIMENTAL RESEARCH OF SHEAR-DRIV...

2024 CSAA/IET International Conference on Aircraft Utility systems, AUS 2024

作者： Li, Qinyang Guan, Ning Ning, Bo Zhu, Guangya Zhang, Dalin Chen, Weijian Key Laboratory of Aircraft Environment Control and Life Support MIIT Nanjing University of Aeronautics and Astronautics Nanjing China College of Aeronautics Shandong Jiaotong University Changqing University Science and Technology Park No.5001 Haitang Road Jinan China Utility System Design and Research Department Jiangxi Hongdu Aviation Industry Group Company Ltd. Nanchang China

The supercooled water droplets in the air will form a water film on the aircraft during flight, which will then form icing, which will have an impact on the aerodynamic performance of the aircraft and even endanger the flight safety. In this paper, based on the Eulerian Wall Films model, the partial wetting effect is introduced, and the water film flow on flat plates driven by airflow shear force is investigated. The flow behaviours of water film with different contact angles under different flow rates were explored through water film test. The effectiveness of the calculation method for water film flow characteristics in this paper was verified by comparison between numerical simulation and test records, which laid a foundation for the anti-icing calculation in subsequent studies. © The Institution of Engineering & technology 2024.

关键词： Shear flow

A Position Probability Prediction Method of Marine Moving Targets for Optimization Search by Satellite

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A Position Probability Prediction Method of Marine Moving Ta...

IEEE International Conference on Control science and systems Engineering (CCSSE)

作者： Xiao Zheng Xiaodong Peng Zhiyuan Guo Huimin Qiang Junbao Zhao Laboratory of System Simulation and Concurrent Design Technology (National Space Science Center Chinese Academy of Sciences) University of Chinese Academy of Science Beijing China Beijing Remote Sensing Information Institute Beijing China

ISBN: (数字)9798331517199

ISBN: (纸本)9798331517205

Marine moving ship target search has great application demand and development prospects in marine surveillance, marine search and rescue, customs anti-smuggling, and other aspects. Satellites are a vital means of searching for marine moving targets. Ground coverage for imaging satellites is relatively limited; the vast marine area makes searching for marine moving ships challenging. Target position prediction, used as the guidance information for satellite detection to reduce the uncertainty of the target position and improve search efficiency, is an essential approach to achieving target optimization search. This paper proposes a target position prediction method based on joint learning of multi-source factors for optimal satellite search of marine moving targets. Firstly, it analyzes the characteristics of marine moving targets and the factors affecting motion. Then, it puts forward the motion prediction model based on a deep neural network, integrating multifactor, like the state of the moving target, environmental attributes such as nautical charts, meteorology and hydrology, and kinematic constraints, to predict the target positional distribution probability. Finally, the target search strategy based on the maximum sum of the distribution probabilities of the satellite coverage area is adopted to improve target detection probability. The experiment results show that the prediction method can realize the target positional distribution probability prediction, reduce the uncertainty search when making the satellite search plan, and improve efficiency.

关键词： Satellites Uncertainty Object detection Kinematics Predictive models Search problems Satellite navigation systems Marine vehicles Modeling Optimization

A numerical method for predicting bursting strength of composite rocket motor case considering filament winding process-induced stress

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Chinese Journal of Aeronautics 2025年第2期 509-522页

作者： Jiqiu LIANG Fei ZHAO Dan WU Anxin DING Hubei Key Laboratory of Advanced Aerospace Propulsion Technology System Design Institute of Hubei Aerospace Technology Academy School of Materials Science and Engineering Wuhan University of Technology State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology

A numerical method to predict the bursting strength of filament wound composite rocket motor case is proposed here. This method can evaluate the longitudinal stress evolution of each composite layer as impregnated filaments with fiber tension are wound layer by layer, and consider the effects of accumulated stress and deformation during filament winding on the bursting strength of composite case. Taking ?520 mm composite cases as a case study, the filament-winding-processinduced stress and deformation as well as progressive damage behavior are numerically predicted,followed by a comparison with experimental results. The numerical results show that the predicted bursting pressures for composite cases manufactured on the mandrels with and without a flexible component are 14.20 MPa and 21.40 MPa, respectively. These values exhibit slight deviation from the measured pressures of 13.50 MPa and 21.57 MPa. Moreover, the predicted damage locations,situated respectively in the dome and cylinder, agree well with the experimental observation. These observations indicate that use of flexible component reduces the load-bearing capacity of the ***, it validates the reliability and accuracy of the proposed numerical method in predicting the bursting strength of composite cases.

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Chemical Speciation Distribution and Thermal Stability of Heavy Metals Along Flue Gas Cleaning systems in a Hazardous Waste Incinerator

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SSRN 2022年

作者： Li, Wenhan Ma, Zengyi Deng, Lilin Huang, Qianming Zhai, Zian Huang, Bochen Liu, Ting Wang, Shuang Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China State Key Laboratory of Clean Energy Utilization Institute for Thermal Power Engineering Zhejiang University Hangzhou310027 China

In this study, chemical speciation distribution and thermal stability of heavy metals (As, Cd, Cr, Cu, Pb, Se, Zn, and Hg) along flue gas cleaning systems were investigated in a hazardous waste incinerator located in Zhejiang, China. The chemical speciation and thermal stability of heavy metals, environmental risk evaluation, and morphological and mineralogical characteristics of incineration residues were assessed before and after heat treatments at different temperatures. The results showed that As and Cr in the raw incineration residues mainly fractionated as the residual form with the proportion of over 48.9% and 74.5%, respectively, whereas most of Se was associated with the oxidizable and residual fraction. The chemical speciation of Cu and Pb in bag filter ashes was related to the chlorine content in the waste, and high chlorine availability favored the formation of acid soluble Cu and Pb. The residual fraction of Hg (over 68.0%) was the most dominant in bag filter ashes, which might exist in the form of HgS. During heat treatments at different temperatures, the vaporization of heavy metals increased with increasing temperature. As, Cr and Se showed high thermal stability due to the fact that As, Cr and Se were involved in the crystallization reaction, and heat treatment would promote the transformation from the mobile fractions into residual fraction. Hg and Cd displayed the worst thermal stability, and high temperature heat treatment would contribute to secondary volatilization from the incineration residues. Cu, Pb and Zn had moderate thermal stability, and heat treatment would cause the volatilization of the mobile fractions or transformation from the mobile fractions into residual fraction. With the increase of heat treatment temperature, the environmental risk of incineration residues displayed a decreasing trend and reached the medium risk level or below after heat treatment at 1200 °C without any additives or pretreatments. © 2022, The Authors. All ri

关键词： Heavy metals

Creep Behavior of a Novel Ods Ferrite Steel Reinforced with Ultra-Fine Y2(Zr0.6, Ti0.4)2O7 Particles

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SSRN 2024年

作者： Zhao, Zhenyu Cao, Yuankui Zhang, Yuyang Fu, Ao Zhang, Ruiqian Zhong, Yuntao Li, Jia Fang, Qihong Liu, Bin State Key Laboratory of Powder Metallurgy Central South University Changsha410083 China Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of China Chengdu610041 China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body China

Oxide dispersion strengthened (ODS) ferrite steel is a competitive candidate structural material for the Generation IV fission reactors. In this work, a novel ODS ferrite steel reinforced with ultra-fine Y2(Zr0.6, Ti0.4)2O7 particles was prepared by powder metallurgy method, which exhibit superior mechanical properties at elevated temperatures. Creep tested of the ODS ferrite steel at 800 ℃ was conducted to reveal its high-temperature creep failure mechanism. This ODS steel has an average grain size of 1.31 μm, and the mean size and number density of the ultra-fine oxide particles are 5.48 nm and 4.85×1023 m-3, respectively. When the apply creep stress is 100 MPa, the creep rupture time of the ODS steel is 2448.5 h, and the minimum creep rate is only 1.05×10-7 s-1. Under the similar creep stress at 800 ℃, the creep rate of this ODS steel is at least one order of magnitude lower than that of other typical ODS steels reported in the literatures, showing excellent creep properties. By fitting the data of minimum creep rate, apply stress and effective stress normalized by shear modulus, the creep threshold stress of the ODS steel was determined as 56.2 MPa, and the true stress exponent was calculated as 4.5 ± 1.0, which indicates that the creep mechanism is dominated by dislocation. Orowan bypass mechanism and dislocation climb over the particle mechanism play a major role in this dislocation mediated creep behavior. Due to the strong hindering effect of dislocation motion caused by the ultra-fine and dispersed Y2(Zr0.6, Ti0.4)2O7 particles, the novel ODS ferrite steel thereby achieved excellent creep properties. © 2024, The Authors. All rights reserved.

关键词： Creep

Experimental Study on Surface Characteristics and Thermal Conductivity of New Zirconium Alloy with Oxide Layer

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SSRN 2022年

作者： Zhong, Lei Chen, Deqi Yu, Hongxing Liu, Haidong Chen, Mingjing Liu, Hanzhou Deng, Jian Ding, Shuhua Wu, Dan Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610041 China Key Laboratory of Low-grade Energy Utilization Technologies and Systems Chongqing University Ministry of Education Chongqing 400044 China

The surface properties and thermal conductivity of oxide layer formed on the new zirconium alloy due to high temperature steam oxidation are studied in this paper. The thickness of oxide layer, surface wettability and thermal conductivity are measured. The effects of oxidation temperature and time on the wettability and thermal conductivity of zirconium alloy are analyzed. The results show that zirconium on the surface is fully oxidized to ZrO2 , and the difference of surface wettability is caused by different surface morphology. The characteristics of oxide layer surface cracks will affect the surface wettability. At the same oxidation temperature, with increasing time duration, the size and number of oxide layer cracks increase. The change of thermal conductivity is the result of competition among factors such as the development of recrystallization process, the increase of oxide layer thickness and the influence of pores and cracks. © 2022, The Authors. All rights reserved.

关键词： Wetting

Study on Imc-Pid Control of Once Through Steam Generator for Small Lead Bismuth Fast reactor

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SSRN 2022年

作者： Sun, Aodi Zhang, Ru Xiao, Kai He, Zhengxi Sun, Peiwei Wei, Xinyu Key Laboratory of Advanced Nuclear Energy and Technology Shaanxi Engineering Research Center of Advanced Nuclear Energy Xi’an Jiaotong University Xi’an710049 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China

Due to the particularity of nuclear reactor, it is difficult to adjust the controller parameters by experiment. The simulation calculation inevitably simplifies the actual model. The controller parameters tuned by this model is likely to cause poor performance due to model mismatch. Therefore, the research on the adaptability of the controller to model mismatch has guiding significance for engineering application. In this paper, a once through steam generator(OTSG) for small lead bismuth fast reactor(SLBFR) is established and verified, and the presented model is simplified by three different methods. Internal model control(IMC) and IMC-PID controllers are designed based on the simplified models. With the increase of λ , IMC-PID controller becomes insensitive to model mismatch caused by model linearization, non-minimum phase characteristics, noise and time delay, and has high robustness to model mismatch. However, the robustness to model sacrifices the sensitivity of the system. In the study of rapid power reduction, it is found that large λ will lead to conservative control output, and then make the control performance worse. Through the research of this paper, Method 1 is recommended, and λ is selected between 5 and 10 to design feedwater IMC-PID controller for OTSG of SLBFR. © 2022, The Authors. All rights reserved.

关键词： Model predictive control

Experimental study of thermal and hydraulic characteristics of pressurizertype heating container during blowdown process

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Experimental study of thermal and hydraulic characteristics ...

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

作者： Ke, Bingzheng Gao, Puzhen Wang, Bo Chen, Bowen Li, Ru Tian, Ruifeng Cheng, Kun Lu, Chuan Fundamental Science on Nuclear Safety and Simulation Technology Laboratory Harbin Engineering University Harbin China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China

ISBN: (纸本)9780791883785

Blowdown process is an important process in LOCA. Studying the internal thermal hydraulic characteristics of the pressurizer during LOCA blowdown process can help to accurately analyze the process of the whole LOCA, which is of great significance to reduce the hazard of accidents and improve the safety of nuclear power plants. An experiment system of blowdown process under low pressure conditions is built, and it uses a pressure gauge and a differential pressure level gauge to measure the pressure and liquid level in the pressurizer-type heating container, and uses a thermocouple to measure the temperature in the pressurizer-type heating container at different heights and distances from the centerline. The changes of pressure, liquid level and temperature characteristics during the blowdown process were obtained. The research results show that the higher the heating power, the greater the slope of pressure change in the heating container, and the pressure changes from negative to positive growth;The greater the heating power is, the faster the liquid level decreases, and the liquid level decreases sharply after the blowdown inflection point. The greater the heating power is, the greater the rate of temperature change, from negative growth to positive growth. The temperature change rate after the blowdown inflection point is reduced. As the height increases, the temperature inside the container first increases and then decreases;the further away from the container's centerline, the higher the measured temperature. © 2020 American Society of Mechanical Engineers (ASME). All rights reserved.

关键词： Containers

Development of the Expanding Mandrel Test Facility for Investigation of Zircaloy Cladding Performance Under Loading Strain Rate Similar to Power Ramp

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SSRN 2022年

作者： He, Yanan Wu, Yingwei Qiu, Bowen Lei, Zhao He, Liang Jiao, Yongjun Chen, Ping Tian, Wenxi Su, Guanghui Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology Shaanxi Engineering Research Center of Advanced Nuclear Energy Xi’an Jiaotong University Xi'An710049 China Nuclear Power Institute of China Science and Technology on Reactor System Design Technology Laboratory Chengdu China

The in-pile pellet-cladding interaction (PCI) is the one of challenging problems for conventional UO2-Zicaloy fuel systems, which can threaten the integrity of the fuel rod and lead to the release of fission product. Currently, several experiments and numerical studies have been devoted to PCI analysis. However, attributing the lacking of experimental data with high fidelity, the development, and validation of the PCI analysis model is not sufficient. In this study, an expanding mandrel test facility has been developed to investigate PCI behaviors, where the digital image correlation (DIC) measuring system was introduced to online monitor the displacements/strain of cladding outer surface with improved fidelity. In addition, the oxygen content measurement system was employed to identify the failure of cladding. Subsequently, the expanding mandrel test facility was leveraged to investigate the PCI performance of three types of cladding (e.g. N36 cladding, recrystallized Zircaloy4 cladding, and M5 cladding) under both with/without iodine corrosion and cladding real-time strain, failure time and failure strain were recorded. Then, performance comparisons among these claddings were completed and discussed. The results show that the established facility can be applied to expanding mandrel tests under varied theoretical loading strain rates (10~60%/h) and the working environment temperature can reach 350 . Meanwhile, there are three distinct stages for the deformed Zicaloy cladding during the expanding mandrel test. The comparison results suggest that recrystallized Zircaloy4 cladding shows the largest cladding failure strain with/without iodine corrosion under 20%/h theoretical loading strain, while M5 cladding and N36 cladding present considerable performance without iodine corrosion effect. In addition, N36 and recrystallized Zircaloy4 cladding seems more iodine corrosion resistant than that for M5 cladding, which can be beneficial for its in-pile performance. Besides,

关键词： Corrosion resistance