检索结果-南通市图书馆

Mathematical modeling and analysis of gas torque in twin-rotor piston engine

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2013年第12期20卷 3536-3544页

作者：邓豪潘存云徐小军张湘 College of Mechatronic engineering and Automation National University of Defense Technology naval aeronautical engineering institute Qingdao Branch

The gas torque in a twin-rotor piston engine(TRPE) was modeled using adiabatic approximation with instantaneous combustion. The first prototype of TRPE was manufactured. This prototype is intended for high power density engines and can produce 36 power strokes per shaft revolution. Compared with the conventional engines, the vector sum of combustion gas forces acting on each rotor piston in TRPE is a pure torque, and the combustion gas rotates the rotors while compresses the gas in the compression chamber at the same time. Mathematical modeling of gas force transmission was built. Expression for gas torque on each rotor was derived. Different variation patterns of the volume change of working chamber were introduced. The analytical and numerical results is presented to demonstrate the main characteristics of gas torque. The results show that the value of gas torque in TRPE falls to be less than zero before the combustion phase is finished; the time for one stroke is 30° in terms of the rotating angle of the output shaft; gas torque in one complete revolution of the output shaft has a period which is equal to 60° and it is necessary to put off the moment when gas torque becomes zero in order to export the maximum energy.

关键词： rotor piston engine gas torque power density adiabatic process

Effects of pitting corrosion on fatigue life of aluminum alloy Y12CZ based on initial discontinuity state

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2006年第A03期16卷 1319-1322页

作者：郁大照陈跃良胡家林杨茂胜 naval aeronautical engineering Academy Yantai 264001China qingdao branch Naval Aeronautical Engineering AcademyQingdao 266041China

Based on initial discontinuity state (IDS) of material, a preliminary analytical model was presented to evaluate the effect of interaction of pitting corrosion and fatigue loading on the residual fatigue life of aluminum alloy LY12CZ. A life prediction was carried out using constant and variable amplitude loading for various pitting corrosion levels, and the prediction agreed reasonably with the available test data. The results suggest that the combination of a pit and IDS can be treated as the initial crack size. Pitting corrosion causes a significant decrease in fatigue lives with small corrosion depths. But the effect of pit on fatigue life is gradually reduced with increasing pit size. A pit with a constant depth can be applied to the model for long exposure structure. A preliminary recommendation for the pit depth is about 1 mm for LY12CZ. At last the effect of multiple-site corrosion damage (MSCD) on fatigue life was also studied, and the result shows that MSCD can decrease substantially fatigue life compared with that of a single crack.

关键词：铝合金疲劳分析金属腐蚀强度

Analysis of moisture distribution within composite materials in hygrothermal environment

在线全文

学校读者我要写书评

暂无评论

Analysis of moisture distribution within composite materials...

Rapid transfer alignment for SINS of carrier craft

第八届中国功能材料及其应用学术会议

作者： JIN Ping WANG De TAN Xiao-ming qingdao branch of naval aeronautical engineering institute Graduate Students Brigade of naval aeronautical engineering institute

ISBN: (纸本)9783037859698

The moisture absorption behavior of CCF300/BA9916 composites in 70℃ distilled water *** on the moisture absorption experiments,the moisture diffusivity and solubility were gained for FEM *** experiments results show that the moisture absorption behavior of CCF300/BA9916 composites basically conforms the Fickian’s second *** simulation results were coincided with the experimental data,the long-term absorption behavior and moisture distribution concentrations within the specimen were obtained.

关键词： Composites Moisture environment Distribution concentration

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Systems engineering and Electronics 2013年第2期24卷 303-308页

作者： Jingshuo Xu Yongjun Wang Zhicai Xiao qingdao Campus of naval aeronautical and Astronautical University Department of Control engineering Naval Aeronautical and Astronautical University

In order to improve the survival ability and rapid response ability of the carrier craft,a new rapid transfer alignment method of the strapdown inertial navigation system（SINS） on a rocking base is put *** the method,the aircraft carrier does not need any form of ***,interfering motions such as rolling,pitching,and yawing motions caused by sea waves are effectively ***,the deck flexure deformation model is ***,the state space model of transfer alignment is ***,the feasibility of this method is validated by the *** results show that the misalignment angle error can be estimated and reach an anticipated precision-0.2 mrad in 5 s,while the deck deformation angle error can be estimated and reach a better precision- 0.1 mrad in 20 s.

关键词： strapdown inertial navigation system(SINS) transfer alignment carrier aircraft carrier moored.

Register Allocation Algorithm for High-Level Circuit Synthesis for Improved Testability

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2008年第6期13卷 836-842页

作者：成本茂王红杨士元牛道恒靳洋 Department of Automation Tsinghua University qingdao branch Naval Aeronautical Engineering Academy

Register allocation in high-level circuit synthesis is important not only for reducing area, delay, and power overheads, but also for improving the testability of the synthesized circuits. This paper presents an improved register allocation algorithm that improves the testability called weighted graph-based balanced register allocation for high-level circuit synthesis. The controllability and observability of the registers and the self-loop elimination are analyzed to form a weighted conflict graph, where the weight of the edge between two nodes denotes the tendency of the two variables to share the same register. Then the modified desaturation algorithm is used to dynamically modify the weights to obtain a final balanced register allocation which improves the testability of the synthesized circuits a higher fault coverage than other algorithms with Tests on some benchmarks show that the algorithm gives less area overhead and even less time delay.

关键词： high-level synthesis (HLS) register allocation testability weighted graph

CT local reconstruction of solid rocket motor based on PI-POCS-TVM

在线全文

学校读者我要写书评

暂无评论

航空动力学报 2017年第2期32卷 470-476页

作者： LU Hong-yi CHEN Qing-gui ZHU Min LI Peng ZHAO Ru-yan WANG Bin Airborne Vehicle engineering Department Naval Aeronautical and Astronautical University Yantai Shandong 264001 China qingdao branch Naval Aeronautical and Astronautical University Qingdao Shandong 266041 China No. 7 Department Naval Aeronautical and Astronautical University Yantai Shanctong 264001 China

In order to test the defects of solid rocket motor(SRM)accurately and efficiently,the computed tomography(CT)inspection scheme for SRM's defects was investigated and a CT local reconstruction algorithm called prior information-projection onto convex sets-total variation minimization(PI-POCS-TVM)was *** SRM was first inspected by industrial CT(ICT)to generate a low-resolution SRM image used as the prior information,then high-resolution local inspection was carried out for SRM's *** validate the effectiveness of the CT inspection scheme for SRM's defects,one SRM was inspected by a narrow fan beam ICT *** back projection(FBP)algorithm,POCS,POCS-TVM and PI-POCS-TVM algorithms were applied to reconstruct CT *** performance of these algorithms was also *** demonstrated the effectiveness of the CT inspection scheme for SRM's ***,the PI-POCS-TVM algorithm has better local reconstruction image quality than the other three algorithms,showing great significance for accurate measurement of SRM's defects.

关键词： interior tomography exterior tomography compressed sensing prior information projection onto convex sets-total variation minimization(POCS-TVM) solid rocket motor

An Improved Local Weighted Linear Prediction Model for Chaotic Time Series

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2014年第2期31卷 16-20页

作者：曲建岭王小飞乔豫川高峰邸亚洲 Department of Control Naval Aeronautical Engineering Institute Qingdao Branch Qingdao 266041 Department of Radiology Leiden University Medical Center 2300 RC Leiden Netherlands

Previous research working on local prediction state with some unsuitable neighbor points （such as false points and pseudo-false neighbor points） are the main source of errors of local prediction and these unsuitable neighbors cannot be eliminated entirely. Therefore, an improved local weighted linear prediction model based on local integrated correlation, which can reduce the influence of the residual unsuitable neighbors, is proposed to predict chaotic time series in our study. Simulation results show that the performance of the improved model is superior to the other local prediction models in the prediction of chaotic time series without and with additive white Gaussian noise.

关键词： TIME series analysis CHAOS theory PREDICTION models ERROR analysis (Mathematics) PERFORMANCE evaluation

Restoration of space-variant blurred image based on motion-blurred target segmentation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems engineering and Electronics 2010年第2期21卷 191-196页

作者： Yuye Zhang Xuewei Wang Chunxin Wang qingdao branch Navy Aeronautical and Astronautical University Qingdao 266041 R R. China Control engineering Department Naval Aeronautical and Astronautical University Yantai 264001 R R. China

In imaging on moving target, it is easy to get space- variant blurred image. In order to recover the image and gain recognizable target, an approach to recover the space-variant blurred image is presented based on image segmentation. Be- cause of motion blur＇s convolution process, the pixels of observed image＇s target and background will be displaced and piled up to produce two superposition regions. As a result, the neighbor- ing pixels in the superposition regions will have similar grey level change. According to the pixel＇s motion-blur character, the target＇s blurred edge of superposition region could be detected. Canny operator can be recurred to detect the target edge which parallels the motion blur direction. Then in the segmentation process, the whole target image which has the character of integral convolution between motion blur and real target image can be obtained. At last, the target image is restored by deconvolution algorithms with adding zeros. The restoration result indicates that the approach can effectively solve the kind of problem of space-variant motion blurred image restoration.

关键词： image restoration space-variant blur image segmen- tation motion-blur.

Strategy dominance mechanism of autonomous collaboration in unmanned swarm within the framework of public goods game

在线全文

学校读者我要写书评

暂无评论

Journal of Systems engineering and Electronics 2023年第5期34卷 1252-1266页

作者： PAN Li WU Zhonghong YU Minggang LIU Jintao MEI Dan Weaponry engineering College Naval University of EngineeringWuhan 430000China Electronics engineering College Naval University of EngineeringWuhan 430000China Coastal Defense College Naval Aeronautical UniversityYantai 264001China qingdao Campus Naval Aeronautical UniversityQingdao 266000China

The key advantage of unmanned swarm operation is its autonomous cooperation. How to improve the proportion of cooperators is one of the key issues of autonomous collaboration in unmanned swarm operations. This work proposes a strategy dominance mechanism of autonomous collaboration in unmanned swarm within the framework of public goods game. It starts with the requirement analysis of autonomous collaboration in unmanned swarm;and an aspiration-driven multiplayer evolutionary game model is established based on the requirement. Then the average abundance function and strategy dominance condition of the model are constructed by theoretical derivation. Furthermore, the evolutionary mechanism of parameter adjustment in swarm cooperation is revealed via simulation,and the influences of the multiplication factor r, aspiration levelα, threshold m and other parameters on the strategy dominance conditions were simulated for both linear and threshold public goods games(PGGs) to determine the strategy dominance characteristics;Finally, deliberate proposals are suggested to provide a meaningful exploration in the actual control of unmanned swarm cooperation.

关键词： unmanned combat swarm autonomous collabora-tion strategy dominance multi-player public goods game(PGG)