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多元线性回归在引气系统故障诊断中的应用
Application of multiple linear regression to fault diagnosis of bleed air system
 [PDF]

梁坤,左洪福,孙见忠,王容辉
- , 2015, DOI: 10.13700/j.bh.1001-5965.2014.0633
Abstract: 摘要 针对利用快速存取记录器(QAR)数据进行民机系统故障诊断问题,以民机引气系统为对象,提出了一种适合多飞行循环数据特点的多元线性回归模型的故障检测方法.首先建立了多飞行循环数据的引气系统性能多元线性回归模型,设计了飞行循环和飞行循环内故障检测方法;然后采用最大后验估计方法进行模型参数估计;最后设计了适合多飞行循环数据的模型参数最大后验估计算法.借助仿真数据和航空公司收集的实际飞行数据对方法进行了验证,结果表明了该方法有效且具有一定工程应用价值.
Abstract:To solve the fault diagnosis problem of civil aircraft systems by utilizing quick access record(QAR) data, with the civil aircraft bleed air system as the research object, we proposed a fault detection method of multiple linear regression model for multi-flight cycle data characteristics. Firstly, the multi-linear regression model of bleed air system performance was established for multi-flight cycles data and the fault detection method of flight cycles and flight cycle's interior was designed. Then the model parameters were estimated by maximum posteriori method. Finally, the maximum posteriori estimation algorithm of the model parameters was designed for multi-flight cycle data. With simulated data and actual flight data collected by airlines, the method was validated. The results show the method's feasibility and application value in engineering practice.
COMPARATIVE ANALYSIS OF TRANSPORT AIRCRAFT, BACKROUND FOR SHORT/ MEDIUM COURIER TRANSPORT AIRCRAFT PROCUREMENT  [PDF]
Neculai P?UN,Matei POPA
INCAS Bulletin , 2010, DOI: 10.13111/2066-8201.2010.2.1.7
Abstract: In accordance with Air Force requirements, the comparative analysis of short/medium transport aircraft comes to sustain procurement decision of short/medium transport aircraft. This paper presents, in short, the principles and the results of the comparative analysis for short/medium military transport aircraft.
Path instabilities of air bubbles rising in clean water  [PDF]
Mingming Wu,Moteza Gharib
Physics , 1998,
Abstract: Experiments are conducted to study the path and shape of single air bubbles (diameter range 0.10- 0.20cm) rising freely in clean water. The experimental results demonstrate that the bubble shape has a bistable state, i. e. the bubble chooses to be in spherical or ellipsoidal shape depending on its generation mechanism. The path of a spherical/ellipsoidal bubble is found to change from a straight path to a zigzag/spiral path via a supercritical/subcritical bifurcation when the Reynolds number of the bubble exceeds a threshold.
AIRCRAFT CONFLICTS RESOLUTION BY COURSE MANEUVERING РОЗВ’ЯЗАННЯ КОНФЛ КТНИХ СИТУАЦ Й М Ж ПОВ ТРЯНИМИ КОРАБЛЯМИ МАНЕВРУВАННЯМ КУРСОМ ПОЛЬОТУ РОЗВ’ЯЗАННЯ КОНФЛ КТНИХ СИТУАЦ Й М Ж ПОВ ТРЯНИМИ КОРАБЛЯМИ МАНЕВРУВАННЯМ КУРСОМ ПОЛЬОТУ  [cached]
В. Харченко,Д. Василь?в
Proceedings of National Aviation University , 2011,
Abstract: Enhancement of requirements for air traffic efficiency at increasing of flights intensity determines the necessity of development of new optimization methods for aircraft conflict resolutions. The statement of problem of optimal conflict resolutions at Cooperative Air Traffic Management was done. The method for optimal aircraft conflict resolution by course maneuvering has been developed. The method using dynamic programming provides planning of aircraft conflict-free trajectory with minimum length. The decomposition of conflict resolution process on phases and stages, definition of states, controls and recursive equations for generation of optimal course control program were done. Computer modeling of aircraft conflict resolution by developed method was done Розглянуто метод оптимального розв’язання конфл ктних ситуац й м ж пов трянимикораблями маневруванням курсом польоту при кооперативному керування пов тряним ру-хом. Запропонований метод з урахуванням р зних обмежень забезпечу планування безконф-л ктно тра ктор польоту з м н мальною в дстанню.The method for optimal aircraft conflict resolution by course maneuvering at Cooperative AirTraffic Management is considered. Proposed method provides planning of conflict-free trajectorywith minimum length in accordance with different limitations.Рассмотрен метод оптимального разрешения конфликтных ситуаций между воздушнымисудами маневрированием курсом полета при кооперативном управлении воздушным движени-ем. Предложенный метод с учетом разных ограничений обеспечивает планирование бесконф-ликтной траектории полета с минимальным расстояннием. Показано, що п двищення вимог до ефективност пов тряного руху при спостережуваномузб льшенн нтенсивност польот в зумовлю необх дн сть розроблення нових оптим зац й-них метод в та алгоритм в розв’язання конфл ктних ситуац й м ж пов тряними кораблями. Зроблено постановку задач оптимального розв’язання конфл ктних ситуац й при кооперати-вному керуванн пов тряним рухом. Розро
Impacts of aircraft emissions on the air quality near the ground
H. Lee,S. C. Olsen,D. J. Wuebbles,D. Youn
Atmospheric Chemistry and Physics Discussions , 2013, DOI: 10.5194/acpd-13-689-2013
Abstract: The continuing increase in demand for commercial aviation transport raises questions about the effects of resulting emissions on the environment. The purpose of this study is to investigate, using a global chemistry transport model, to what extent aviation emissions outside the boundary layer influence air quality in the boundary layer. The effects of current levels of aircraft emissions were studied through comparison of multiple simulations allowing for the separated effects of aviation emissions occurring in the low, middle and upper troposphere. We show that emissions near cruise altitudes rather than emissions during landing and take-off are responsible for most of the total odd-nitrogen (NOy), ozone (O3) and aerosol perturbations near the ground with a noticeable seasonal difference. Overall, the perturbations of these species are smaller than 1 ppb even in winter when the perturbations are greater than in summer. Based on the widely used air quality standards and uncertainty of state-of-the-art models, we conclude that aviation-induced perturbations have a negligible effect on air quality even in areas with heavy air traffic. Aviation emissions lead to a less than 1% aerosol enhancement in the boundary layer due to a slight increase in ammonium nitrate (NH4NO3) during cold seasons and a statistically insignificant aerosol perturbation in summer. In addition, statistical analysis using probability density functions, Hellinger distance, and p-value indicate that aviation emissions outside the boundary layer do not affect the occurrence of extremely high aerosol concentrations in the boundary layer. An additional sensitivity simulation assuming the doubling of surface ammonia emissions demonstrates that the aviation induced aerosol increase near the ground is highly dependent on background ammonia concentrations whose current range of uncertainty is large.
The influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation.  [cached]
Fi?er J.,Jícha M.
EPJ Web of Conferences , 2013, DOI: 10.1051/epjconf/20134501102
Abstract: The paper deals with instigation of influence of air duct geometry on air jet direction in aircraft cabin ventilated by mixing ventilation. CFD approach was used for investigation and model geometry was based on small aircraft cabin mock-up geometry. Model was also equipped by nine seats and five manikins that represent passengers. The air jet direction was observed for selected ambient environment parameters and several types of air duct geometry and influence of main air duct geometry on jets direction is discussed. The model was created in StarCCM+ ver. 6.04.014 software and polyhedral mesh was used.
Cost - Benefit Assessment of Aircraft Safety  [PDF]
Ivana ?avka,Olja ?okorilo
International Journal for Traffic and Transport Engineering , 2012,
Abstract: The constant increase of air traffic volume causes the requirements for development and implementation of numerous measures that will enable monitoring of the safety level in the aviation organizations. An inseparable element of the process of implementing an adequate safety management system in aviation refers to the analysis of economic parameters for assessing the risk of aircraft accidents. Based on the statistical data related to the accidents of aircraft A320, which is considered in this paper, the main indicators of safety were analyzed. However, since aircraft accidents are among a group of rare events, historical data may not always be used to determine the level of safety. In such cases, it is necessary to develop mathematical models that will calculate the safety level. Therefore, this paper presents a methodology for assessing the costs of safety in the event of an aircraft accident, and which is a useful tool in the safety management system that could indicate the potential financial loss in case of an aircraft accident, but also the benefits that may arise by making investments in improving the safety level.
ECONOMIC AND ENVIRONMENTAL ASPECTS ON ENERGY ALTERNATIVES FOR A CLEAN AIR – WIND FARMS  [PDF]
PAUL CALANTER,OCTAVIAN SERBAN,ANCA DRAGOMIR
Aerul ?i Apa : Componente ale Mediului , 2011,
Abstract: Economic and environmental aspects on energy alternativesfor a clean air – wind farms. Wind energy represents an increasingly moreattractive alternative in Romania. Regulations concern investment and operationof installations, but also energy recovery and environmental protection. Windfarms development, sustained by landscape, wind speed distribution and investorsfinancial promotion, competes with the prudence imposed by the potentialenvironmental impact (biodiversity, microclimate, etc), and the lack of historicaldata and information structuring. Adequate organization and dissemination ofrelevant information might be valuable for investors and sustainable developmentstrategies.
Evaluation of Clean Air from Viewpoint of Tile Industry Personnel
F Golbabaei,H Nazeman,SJ Shahtaheri,AR Kouhpaei
Iranian Journal of Public Health , 2002,
Abstract: The purpose of this study was to determine evaluation of clean air from viewpoint of tile industry personnel at two pressing workplaces, in order to utilize the results for economic policy making of air pollution control. Total dust was measured on the basis of NIOSH Method 0500, showing dust concentration of 59.26 ±15.81 mg/m3 and 32.16 ±9.85 mg/m3 in the mentioned workplaces. The value of clean air was determined, using Contingent Evaluation Method from the viewpoint of 100 workers (50 workers in each workplace) as case group, and 100 administrative personnel as control group. The results demonstrated that, the average payments by workers are 77500 and 16700 Rials per person monthly in the case and control groups respectively. The workers were exposed to 3 options as: discount in payment of insurance premium and tax, causing an increase in partnership monthly payment in the case group: 39% and 55% respectively, and in the control group equivalent to 20% and 36% respectively. It is worth mentioning that, to pay loan to the workers did not indicate any significant difference between case and control groups partnerships.
Prediction of air temperature in the aircraft cabin under different operational conditions  [cached]
Volavy F.,Fi?er J.,N?ske I.
EPJ Web of Conferences , 2013, DOI: 10.1051/epjconf/20134501096
Abstract: This paper deals with the prediction of the air temperature in the aircraft cabin by means of Computational Fluid Dynamics. The simulations are performed on the CFD model which is based on geometry and cabin interior arrangement of the Flight Test Facility (FTF) located at Fraunhofer IBP, Germany. The experimental test flights under three different cabin temperatures were done in FTF and the various data were gathered during these flights. Air temperature in the cabin was measured on probes located near feet, torso and head of each passenger and also surface temperature and air temperature distributed from inlets were measured. The data were firstly analysed in order to obtain boundary conditions for cabin surfaces and inlets. Then the results of air temperature from the simulations were compared with measured data. The suitability and accuracy of the CFD approach for temperature prediction is discussed.
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