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A comprehensive aerodynamic-thermalmechanical design method for fast response turbocharger applied in aviation piston engines

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Propulsion and Power Research 2024年第2期13卷 145-165页

作者： Yu Zhou Yue Song Shuai Zhao Xueyu Li Longtao Shao Huansong Yan Zheng Xu shuiting Ding Research Institute of Aero-Engine Beihang UniversityBeijing 100083China Aircraft/Engine Integrated System Safety Beijing Key Laboratory Beijing 100083China School of Energy and Power Engineering Beihang UniversityBeijing 100083China School of Transportation Science and Engineering Beihang UniversityBeijing 100083China AVIC Nanjing Engineering Institute of Aircraft Systems Nanjing 210000China Hangzhou International Innovation Institute Beihang UniversityHangzhou 311115China Civil Aviation University of China Tianjin 300300China

Limited by the poor transient response performance of turbochargers,the dynamic performance of aviation piston engines tends to *** a bid to enhance the turbocharger’s acceleration capabilities,this study scrutinizes various factors impacting its *** on the operational principles and transient response process of the turbocharger,three types of in-ertiadnamely,aerodynamic inertia(ADI),thermal inertia(TI),and mechanical inertia(MI)d are identiﬁed and addressed for *** begin,this paper pioneers the innovative deﬁnition of a method for evaluating the transient response performance of the *** method incor-porates the introduction of an ADI parameter,inspired by the deﬁnition of ***,a thin-walled volute design with a low Biot number and a lightweight turbine impeller is introduced to reduce the turbocharger’s TI and *** simulation results of theﬂowﬁeld distribution within the volute and diffuser demonstrate the comprehensive design method’s effectiveness in improving gas pressure and temperature distributions in these ***,the pressure distributionﬂuctuation in the constant moment-of-momentum volute(CMV)is 62.8%lower than that in the constant velocity moment volute(CVMV).The low-TI thin-walled volute not only en-hances the turbocharger’s response speed but also reduces its weight by approximately 40%.The impact of three types of inertia on the engine’s response speed is quantiﬁed as follows:ADI(94%)>MI(5%)>TI(1%).This conclusion has been veriﬁed through test results of both the turbocharger and the *** design method not only signiﬁcantly improves the turbo-charger’s response performance but also offers valuable insights for the optimal design of other blade mechanical systems.

关键词： Turbocharger Fast response design method Aerodynamic inertia Thermal inertia Mechanical inertia

Gas exchange optimization in aircraft engines using sustainable aviation fuel:A design of experiment and genetic algorithm approach

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Energy and AI

Energy and AI 2024年第3期17卷 261-280页

作者： Zheng Xu Jinze Pei shuiting Ding Longfei Chen Shuai Zhao Xiaowei Shen Kun Zhu Longtao Shao Zhiming Zhong Huansong Yan Farong Du Xueyu Li Pengfei Yang Shenghui Zhong Yu Zhou Hangzhou International Innovation Institute Beihang UniversityHangzhou311115China Research Institute of Aero-Engine Beihang UniversityBeijing102206China Civil Aviation University of China Tianjin300300China Aircraft/Engine Integrated System Safety Beijing Key Laboratory Beijing100083China Aero Engine Academy of China Beijing101304China School of Energy and Power Engineering Beihang UniversityBeijing100083China AVIC Chengdu Aircraft Design and Research Institute Chengdu610091China AVIC Nanjing Engineering Institute of Aircraft Systems Nanjing211106China School of Transportation Science and Engineering Beihang UniversityBeijing100083China Faculty of Science and Engineering University of Nottingham Ningbo ChinaNingbo315100China

The poppet valves two-stroke(PV2S)aircraft engine fueled with sustainable aviation fuel is a promising option for general aviation and unmanned aerial vehicle propulsion due to its high power-to-weight ratio,uniform torque output,and flexible valve ***,its high-altitude gas exchange performance remains unexplored,presenting new opportunities for optimization through artificial intelligence(AI)*** study uses validated 1D+3. models to evaluate the high-altitude gas exchange performance of PV2S aircraft *** valve timings of the PV2S engine exhibit considerable flexibility,thus the Latin hypercube design of experiments(DoE)methodology is employed to fit a response surface model.A genetic algorithm(GA)is applied to iteratively optimize valve timings for varying *** optimization process reveals that increasing the intake duration while decreasing the exhaust duration and valve overlap angles can significantly enhance high-altitude gas exchange *** optimal valve overlap angle emerged as 93.CA at sea level and 82°CA at 4000 m *** effects of operating parameters,including engine speed,load,and exhaust back pressure,on the gas exchange process at varying altitudes are further *** higher engine speed increases trapping efficiency but decreases the delivery ratio and charging efficiency at various *** effect is especially pronounced at elevated *** increase in exhaust back pressure will significantly reduce the delivery ratio and increase the trapping *** study demonstrates that integrating DoE with AI algorithms can enhance the high-altitude performance of aircraft engines,serving as a valuable reference for further optimization efforts.

关键词： Poppet valves two-stroke Design of experiment Genetic algorithm optimization Heavy fuel aircraft engine High altitude gas exchange performance

复合翼eVTOL电池需求及对动力总成安全性的影响

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推进技术 2024年第3期45卷 207-221页

作者：丁水汀丁硕孙爽但敏赵自庆中国民航大学航空工程学院天津300300

动力电池是电动化飞行得以实现的重要组成部分,其技术层次和安全水准对电动垂直起降飞行器(Electric Vertical Take off and Landing aircraft,eVTOL)的商业化推广尤为重要。本文在典型飞行任务下,研究电池性能对eVTOL飞行器的运营性能... 详细信息

动力电池是电动化飞行得以实现的重要组成部分,其技术层次和安全水准对电动垂直起降飞行器(Electric Vertical Take off and Landing aircraft,eVTOL)的商业化推广尤为重要。本文在典型飞行任务下,研究电池性能对eVTOL飞行器的运营性能、适航性能和安全性能的影响。利用开源软件SUAVE(Stanford University Aerospace Vehicle Environment,SUAVE)对复合翼eVTOL进行了整机与动力总成的建模,利用故障树分析(Fault Tree analysis,FTA)方法对动力总成进行了安全性分析。通过仿真,发现在现有电池技术水平下,电池的放电倍率约束是决定电池性能需求的关键限制条件,针对本文设计的eVTOL,3.2 Wh/kg是满足所有安全约束的最低能量密度,在使用过程中电池容量的衰退是设计者选择电池能量密度的重要参考指标。单独改善电池的可靠性对动力总成可靠性的提升是有限的,但电池性能的衰退将使电池成为动力总成失效的主要因素。通过FTA发现本文搭建的典型动力总成失效率为1.524×10^(-7),接近SC-VTOL-01中单座飞行器的基础级灾难性故障率要求。

关键词：复合翼eVTOL 电池全电动力总成故障树分析安全性

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主动脉疾病腔内治疗进展及展望

中华放射学杂志 2024年第10期58卷 1092-1096页

作者：李晓健王国权王琼翟水亭郑州大学阜外华中心血管病医院血管中心郑州

目前, 腔内治疗已成为主动脉疾病的首选治疗方法, 在临床上被广泛应用于胸腹主动脉瘤、Stanford B型主动脉夹层等疾病的治疗, 并取得了良好的中远期疗效, 尤其是随着腔内技术和器材的发展, 对于累及内脏区及主动脉弓部分支血管的复杂主... 详细信息

目前, 腔内治疗已成为主动脉疾病的首选治疗方法, 在临床上被广泛应用于胸腹主动脉瘤、Stanford B型主动脉夹层等疾病的治疗, 并取得了良好的中远期疗效, 尤其是随着腔内技术和器材的发展, 对于累及内脏区及主动脉弓部分支血管的复杂主动脉病变, 通过各种先进的腔内技术治疗也取得了令人满意的效果。但对于升主动脉包括主动脉根部病变, 尽管国内外诸多研究机构做了许多大胆的尝试, 但临床效果甚微, 仍然为血管腔内干预的相对禁区。近年来, 随着腔内治疗理念的更新及创新器具的不断涌现, 主动脉疾病的腔内治疗适应证不断扩大, 并发症大大降低及临床预后持续改善, 主动脉疾病腔内治疗的安全性及有效性得到了显著提升, 未来发展前景良好。

关键词：主动脉疾病主动脉夹层腹主动脉瘤腔内修复术介入放射学

Safety Analysis of Flow Parameters in a Rotor-stator Cavity

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Chinese Journal of Aeronautics 2012年第6期25卷 831-838页

作者： ZHANG Gong DING shuiting Airworthiness Technologies Research Center Beihang University Beijing 100191 China National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics School of Jet Propulsion Bei hang University Beij ing 100191 China

In order to ensure the safety of engine life limited parts （ELLP） according to airworthiness regulations, a numerical approach integrating one-way fluid structure interaction （FSI） and probabilistic risk assessment （PRA） is developed, by which the variation of flow parameters in a rotor-stator cavity on the safety of gas turbine disks is investigated. The results indicate that the flow parameters affect the probability of fracture of a gas turbine disk since they can change the distribution of stress and temperature of the disk. The failure probability of the disk rises with increasing rotation Reynolds number and Chebyshev number, but descends with increasing inlet Reynolds number. In addition, a sampling based sensitivity analysis with finite difference method is conducted to determine the sensitivities of the safety with respect to the flow parameters. The sensitivity estimates show that the rotation Reynolds number is the dominant variable in safety analysis of a rotor-stator cavity among the flow parameters.

关键词： airworthiness aircraft engines engine life limited parts safety analysis rotor-stator cavity risk assessment

Sensitivity Analysis for Safety Design Verification of General Aviation Reciprocating Aircraft Engine

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Chinese Journal of Aeronautics 2012年第5期25卷 675-680页

作者： CAO Jiaokun DING shuiting Airworthiness Technologies Research Center Beihang UniversityBeijing 100191China

This paper presents an application of global sensitivity analysis for system safety analysis of reciprocating aircraft engine. Compared with local sensitivity analysis results, global sensitivity analysis could provide more information on parameter inter- actions, which are significant in complex system safety analysis. First, a deterministic aviation reciprocating engine thermody- namics model is developed and parameters of interest are defined as random variables. Then, samples are generated by Monte Carlo method for the parameters used in engine model on the basis of definition of factor distribution. Eventually, results from engine model are generated and importance indices are calculated. Based on the analysis results, design is improved to satisfy the airworthiness requirements. The results reveal that by using global sensitivity analysis, the parameters could be ranked with respect to their importance, including first order indices and total sensitivity indices. By reducing the uncertainty of parameters and adjusting the range of inputs, safety criteria would be satisfied.

关键词： sensitivity analysis safety analysis airworthiness reciprocating aircraft engine design verification

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基于人工神经网络的电力变压器声纹识别技术

沈阳工业大学学报 2024年第4期46卷 380-387页

作者：李瑞琪李燕杜水婷王军华北电力大学电气与电子工程学院河北保定071003 国网甘肃省电力公司数字化事业部甘肃兰州730050

针对变压器运行状态声纹识别的应用需求以及BP神经网络识别模型准确率较低等问题,提出了一种改进人工神经网络的变压器声纹识别技术。该技术以变压器声纹信号中的MFCC系数作为模型的输入特征向量,在BOA算法中引入动态权重因子和变异因子... 详细信息

针对变压器运行状态声纹识别的应用需求以及BP神经网络识别模型准确率较低等问题,提出了一种改进人工神经网络的变压器声纹识别技术。该技术以变压器声纹信号中的MFCC系数作为模型的输入特征向量,在BOA算法中引入动态权重因子和变异因子对BP神经网络权值和阈值进行寻优,开展声纹识别。实验结果表明,利用变压器声纹信号的3.维MFCC特征系数可使识别准确率达到90%以上,优化后算法的运算速度比PSO-BP神经网络与BOA-BP神经网络提高了9.24%和8.64%,具有更高的运算效率和识别准确率。

关键词：声纹识别 BP神经网络特征向量权重因子动态寻优模式识别变异因子状态检测

Identification of key factors affecting the failure of aviation piston engine turbochargers based on an improved correspondence analysis-polar angle-based classification

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Chinese Journal of Aeronautics 2021年第5期34卷 466-484页

作者： Mengyao BAO shuiting DING Guo LI Civil Aviation Management Institute of China Beijing 100102China Aircraft|Engine Integrated System Safety Beijing Key Laboratory Beihang UniversityBeijing 100083China

Turbocharging is an efficient approach for addressing power reduction and oil consumption increase in aviation piston engines during high-altitude ***,a turbocharger significantly increases the complexity of a power system,and its considerably complex matching relation with the engine results in a coupling of failure *** analytical methods are hard to identify failure-inducing ***,safety issues are becoming increasingly *** study focuses on methods for identifying failure-inducing factors.A whole-machine system model is established and validated through *** response surface method is employed to further abstract the system simulation model to a surrogate model(average error:~3.)in order to reduce the computational cost while ensuring *** this basis,an improved Correspondence Analysis(CA)-Polar Angle(PA)-based Classification(PAC)is proposed to identify the key factors affecting the failure mode of *** identification method is based on the row profile coordinates G varying with the numerical deviations of the key factors,and is capable of effectively identifying the key factors affecting the *** a validation example,this method identifies the diameter of the exhaust valve(e_(2))as the primary factor affecting the safety margin for each work boundary.

关键词： Failure-inducing factors Improved correspondence analysis Polar angle Turbochargers Whole-machine system model

HPA轴及海马BDNF与抑郁症的相关性及柴胡经典方治疗研究进展

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实用中医内科杂志 2024年第1期38卷 28-31页

作者：徐水婷胡玉英广西中医药大学广西南宁530001 广西中医药大学第一附属医院广西南宁530023

随着当今时代快速发展,抑郁症已成为人类常见病种,以情绪消沉、沉默寡言、思维迟缓等为主症,严重者甚至有自残、自杀的倾向。抑郁症的发病机制复杂,涉及诸多因素。抗抑郁西药种类多,具有一定的疗效,但存在不良反应大、依从性低及易复发... 详细信息

随着当今时代快速发展,抑郁症已成为人类常见病种,以情绪消沉、沉默寡言、思维迟缓等为主症,严重者甚至有自残、自杀的倾向。抑郁症的发病机制复杂,涉及诸多因素。抗抑郁西药种类多,具有一定的疗效,但存在不良反应大、依从性低及易复发等问题,而中药治疗疗效显著。探讨下丘脑-垂体-肾上腺(HPA轴)、海马脑源性神经营养因子(BDNF)与抑郁症的相关性,对柴胡及其经典复方通过调控HPA轴及海马BDNF发挥抗抑郁作用进行综述,以期为临床研发更多具有抗抑郁作用的中药提供理论参考。

关键词：下丘脑-垂体-肾上腺海马BDNF 抑郁症柴胡经典复方