随着电传操纵技术的日益普及,放宽静稳定布局逐渐在民航飞机上得到应用,但对飞机液压及操纵系统的设计要求也逐步提高。发动机是飞机二次能源的主要来源,单发停车除对飞机飞行性能及操纵品质产生直接影响外,二次能源的损失也会加剧上述影响。通过分析典型放宽静稳定性电传客机的总体气动系统、电源系统、液压系统及飞控系统的设计特征,梳理了单发停车对于液压及飞控的影响,分析了对飞行操纵性及稳定性可能产生的危害。研究表明,电传客机在采用高效的气动设计的同时,在一定程度上削弱了纵向及航向稳定性,需要通过电传操纵的增稳功能予以弥补。高增稳飞控系统要求舵面有较高的偏转速率,应最大程度保证供往飞控舵面的液压流量。电传飞机的操稳特性由本体飞机、电传控制律及液压/舵面的动态特性共同决定,比常规飞机复杂,在设计、审定、使用及维护中应高度重视。

The atmospheric corrosion behavior of 6061 aluminum alloy exposed in industrial and marine atmosphere environments for 36 months has been investigated by weight loss test, tensile strength X‐ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), optical microscope. results showed that, compared with environment, presented higher susceptibility environment. XPS analysis indicated that the major constituents products formed environment were hydroxide, oxide, sulfate. In...

This paper deals with the prediction of long-term atmospheric corrosion in different field environments using power-linear function. A method for calculation exponent n and stationary rate α function is proposed based on 1- 8-y loss results (C1 C8) ISO CORRAG program. The response surface artificial neural network methodology are used to obtain accurate estimation C1 C8 locations environmental variables. Considering uncertainty model experimental data, confidence intervals also calculated....

The effect of cathodic polarization on the corrosion behavior alkyd-resin-coated carbon steel with an artificial coating defect was researched using a wire beam electrode (WBE) and electrochemical impedance spectroscopy (EIS) in both static flowing simulated solutions. microscopic morphology chemical structure organic were characterized by scanning electron microscopy (SEM) infrared (FT-IR) to reveal degradation mechanisms coatings under different potentials. study found that failure process...

The atmospheric corrosion behaviour of 30CrMnSiA high-strength steel exposed in rural, industrial and marine atmosphere environments China for 60 months was investigated virtue the weight loss, X-ray diffractometer (XRD), scanning electron microscope (SEM) grey relational analysis. results showed that exhibited highest susceptibility lowest environment rural environment, respectively. Lepidocrocite goethite were found as major constituents rust layer three types environments, akaganeite also...

Predicting the corrosion loss over time in different environments is challenging because process develops and influenced by multiple environmental factors simultaneously. Conventional regression analysis not applicable it has several limitations dealing with multilevel structured data. In this paper, hierarchical linear modelling method employed instead. A two-level growth model built to analyse individual effects of environment on carbon steel, zinc, copper. Environmental that have...

Corrosion in natural seawater is difficult to simulate a laboratory due the slow rate and complexity of corrosion process which involves multiple influential factors. This paper aims explore quantitative effect environmental factors on find best experimental conditions represent actual environment have acceleration effect. A new framework followed this consists three parts: design experiments, outdoor tests, mechanism consistency confirmation. L6(31 × 22) orthogonal experiment designed study...

Coupler separation is among the serious accidents threatening operation safety of heavy-haul trains. This paper reports a study on formation mechanism and key influencing factors middle coupler 20,000-tonne combined train during air-braking release by means field investigation, theoretical analysis numerical simulation. The interaction state between connected knuckles potential sensitive leading to are investigated based tests analysis. process related analysed through simulations. results...

The effects of periodic wakes and inlet freestream turbulence intensity (FSTI) on coherent structures in the boundary layer a high-lift low-pressure turbine cascade are studied this paper. Large-eddy simulations (LES) performed T106D-EIZ profile at Reynolds number (Re) 60,154 (based chord outflow velocity). Eight cases, considering FSTI 0, 2.5%, 5% 10% as well wake reduced frequency (fr) 0.67, 1.34 0.335, conducted discussed. results show that open separation could be compressed by to small...

There are obvious differences in the corrosion process of materials different climatic regions, and it is great significance to establish model considering effects environmental factors improve adaptability. However, many existing models do not take comprehensive into account, selection these sufficiently investigated. Meanwhile, comparison also based on goodness-of-fit. In order atmospheric prediction use an improved method judge suitable instead traditional goodness-of-fit, this paper...

Mechanism equivalence analysis, focusing on the underlying quantitative relationship between degradation model parameters under different stress levels when accelerated failure mechanism remains unchanged, has been developed and adopted widely in tests (ADTs) over recent years. For a specific process, conditions can be derived based acceleration factor invariant principle further utilized to test whether unchanged or not levels. In this paper, unified form of for commonly-used stochastic...

As to guarantee flight safety when system failures occur, modern fly-by-wire control systems for commercial aircraft incorporate reconfiguration modes. While relaxed static stabilities (RSS) are utilized on most new designed airliners, the flying qualities design become a major concern laws developed. The aim of this paper is analyze reduction activated. Longitudinal and lateral-directional laws, along with their alternative direct modes, were developed longitudinal directional stabilities....

The product’s reliability is influenced by multiple environmental factors in the dynamic field environment. In this article, a assessment method proposed. This links effects of environment to with acceleration models. Three modeling methods are developed taking into full consideration variability, dependency, and randomness Then three applied calculate factor for material exposed corrosive atmosphere time-to-whisker-nucleation semiconductor devices, incorporating nonlinear factors. results...

The relative Ma number from rotor outlet is often quite large in high pressure turbine, especially vaneless counter rotating turbine. Therefore, it necessary that appropriate blades are adopted for working circumstances. In this paper, 13 design parameters firstly chosen through analysis of the key factors affecting turbine performance. Then non-uniform rational B spline method employed to parameterize model blade, and made dynamic geometric associate. Furthermore, a parametric modeling...

Abstract This paper studies the impact of changing climate on atmospheric corrosion loss in future low pollution environment. Two change scenarios (SSP1-2.6 and SSP5-8.5) are studied they reveal a warmer environment with decreasing sulphur dioxide contamination slightly changed relative humidity precipitation from 2010 to 2100. As consequence, corrosivity is both enhanced by increased time-of-wetness weakened decreased deposition rate. To consider climate, error minimized short-term model...

Seismic processing is an important technology in petroleum industry. Processing results are usually observed and analyzed by scientists via interactive applications. In these applications, multidimensional range queries frequently executed to fetch the data that users interested in. The traditional B+-tree index does not work well for because considerable has be scanned from storage devices during query execution. this paper, we present MLB +-tree, a multi-level accelerate on seismic data....

A methodology for automatic quadrilateral mesh generation is presented. It based on a novel application of the Delaunay triangulation algorithm, by which meshes can be generated as easily triangular complex domains. The relative-element size method (RESM) has been used effective priori and posteriori control number distribution elements. An adaptive refinement technique that allows specified solution accuracy to achieved with one or at most two cycles also proposed. Its robustness...