共查询到20条相似文献,搜索用时 687 毫秒
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郑庆 《民用飞机设计与研究》2021,(4):100-103
民机研制过程中,可达性设计要求贯彻不到位,可能会导致飞机存在某些方面的设计缺陷,并在投入运营后不断暴露,影响维修经济性。随着虚拟现实技术和人工智能技术的不断发展,利用虚拟维修技术,通过构建逼真的虚拟环境来对虚拟样机进行维修性分析,能够在研制阶段开展维修性设计评价。由此从民机可达性设计的角度出发,综合考虑维修区域可达性、维修人员可达性、维修工具可达性、维修部件可达性、部件细部可达性五个方面,给出可达性分析结果判据,建立了可达性设计缺陷分析方法,实现研制过程中的可达性设计评价,及时找到设计缺陷并改进,提高飞机维修性。最后以某型飞机电源设备为对象,利用此方法开展了维修可达性分析,给出了应用实例,验证了此方法的可行性。 相似文献
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防空导弹武器系统维修性设计综述 总被引:1,自引:0,他引:1
陈万创 《自动驾驶仪与红外技术》2000,(1):1-8
为满足现代防空导弹武器系统全寿命周期的高维修性要求,我们对其可维修性工程设计进行了探讨。本文主要对防空导弹武器系统的可维修性设计措施作了综述,提出了维修性设计的准则,基本设计方法和维修性验证。 相似文献
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基于模糊综合评判的维修性设计评估 总被引:4,自引:0,他引:4
鉴于影响维修性设计评判的多因素性和不确定性,提出用模糊综合评判法,进行飞机维修性设计的综合评价。在建立模糊综合评判集的基础上,利用层次分析法确定评价因素的分配权重,对维修性设计进行评估。根据评判结果.进行方案选择或做出设计改进,保证维修性设计满足规定的要求。 相似文献
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本文首先简要介绍了航空产品维修性模型建立的一般过程、维修性分配和预计的方法步骤,然后对维修性用不同的方法进行了定性的分析,最后给出了维修性设计应遵循的一般准则。 相似文献
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王洁萱 《民用飞机设计与研究》2021,(1):98-101
民用飞机维修性的好坏直接影响到市场竞争力,是民用飞机成功运营的关键因素之一。维修性预计是民用飞机研制过程中维修性设计的主要工作之一,能够评价设计是否满足维修性要求。抽样评分法作为维修性预计的方法之一,具有样本量小、预计简便、设计初始阶段即可应用的优点。电源系统为飞机的所有用电设备供电,其维修性的好坏直接影响机载设备能否正常运行,对整机的维修性设计起着关键作用。对抽样评分法展开研究,并根据民用飞机维修性设计现状,量化了维修要求的人为因素评分核对表,对抽样评分方法进行了优化。通过抽样评分法对某机型电源系统的维修性进行了预计,评价是否达到维修性设计要求。最后阐述了抽样评分法在民用飞机维修性设计过程中的重要性。 相似文献
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王洁萱 《民用飞机设计与研究》2021,(4):110-113
民用飞机维修性参数选取和指标确定是维修性设计的基础工作之一,为了反映出民用飞机的维修性、运营费用和维修人力等方面的目标,需要选择合适的维修性参数并确定维修性指标。国产民用飞机由于缺少研制经验和设计资料,无法使用成熟方法进行维修性参数选取和指标确定,针对这一问题进行研究。结合民用飞机的设计特点阐述了民用飞机维修性参数的选取方法,通过综合权衡民用飞机设计中各影响因素和维修性参数有效性,从与维修时间相关、与维修工时相关、与维修成本相关的三类参数中选取适当的民用飞机维修性参数。针对民用飞机设计现状,明确维修性指标的确定依据和具有实用性的方法,以使民用飞机具有良好的维修性。解决了国产民用飞机维修性参数选取和指标确定工作无参考依据的问题,为民用飞机维修性参数选取和指标确定提供了一条可行途径。 相似文献
7.
吴昊 《民用飞机设计与研究》2019,(4):92-96
在民用飞机维修性设计中,维修性指标分配是一个重要环节。合理的分配维修性指标,可以使民机各系统在设计过程中省钱省力。在民机初步设计阶段,针对维修分配输入不足,首先利用层次分析法对维修性分配因素进行筛选,再运用模糊数学理论中的综合评判方法,综合考虑多方面的模糊因素,提出了基于设计特性模糊综合的维修性分配模型。最后,结合工程实例利用该方法对维修性指标进行了分配应用,结果表明该方法可用来指导民用飞机各系统的维修性设计工作,达到了维修性分配目的。 相似文献
8.
王洁萱 《民用飞机设计与研究》2022,(3):123-127
维修性设计是民用飞机研制工作中的基础工作之一,维修性的好坏直接影响到民用飞机的经济性和市场竞争力。我国民用飞机维修性设计工作起步较晚,缺少系统的正向方法和技术指导资料。将系统工程实践应用于民用飞机设计过程中,进行正向设计,可以尽可能减少设计工作量,减少返工。将利益攸关方的维修性需求落实到系统设备的维修性设计中,对于民用飞机的维修性设计至关重要。以民用飞机电子电气舱的维修性设计为例,通过需求识别,以需求权重为基础计算得到维修性设计要求的相对重要度。再用关联矩阵法将维修性设计要求落实到民用飞机系统设备的设计上。该方法采用正向设计,为设计出满足用户需求且易于维修的民用飞机提供了设计思路。 相似文献
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The effect of inlet conditions on the flow and heat transfer in multiple rotating cavity with axial throughflow 总被引:1,自引:0,他引:1
This paper discusses experimental results from two different build configurations of a heated multiple rotating cavity test rig.Measurements of heat transfer from the discs and tangential velocities are presented.The test rig is a 70% full scale version of a high pressure compressor stack of an axial gas turbine engine.Of particular interest are the internal cylindrical cavities formed by adjacent discs and the interaction of these with a central axial throughflow of cooling air.Tests were carried out for a range of non-dimensional parameters representative of high pressure compressor internal air system flows(Re up to 5×106 and Rez up to 2×105).Two different builds have been tested.The most significant difference between these two build configurations is the size of the annular gap between the(non-rotating) drive shaft and the bores of the discs.The heat transfer data were obtained from thermocouple measurements of surface temperature and a conduction solution method.The velocity measurements were made using a two component,LDA system.The heat transfer results from the discs show differences between the two builds.This is attributed to the wider annular gap allowing more of the throughflow to penetrate into the cavity.There are also significant differences between the radial distributions of tangential velocity in the two builds of the test rig.For the narrow annular gap,there is an increase of non-dimensional tangential velocity V/Ωr with radial location to solid body rotation V/Ωr=1.For the wider annular gap,the non-dimensional velocities show a decrease with radial location to solid body rotation. 相似文献
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Research on Auto-detection for Remainder Particles of Aerospace Relay Based on Wavelet Analysis 总被引:2,自引:0,他引:2
GAO Hong-liang ZHANG Hui WANG Shu-juan 《中国航空学报》2007,20(1):75-80
Aerospace relay is one kind of electronic components which is used widely in national defense system and aerospace system. The existence of remainder particles induces the reliability declining, which has become a severe problem in the development of aerospace relay. Traditional particle impact noise detection (PIND) method for remainder detection is ineffective for small particles, due to its low precision and involvement of subjective factors. An auto-detection method for PIND output signals is proposed in this paper, which is based on direct wavelet de-noising (DWD), cross-correlation analysis (CCA) and homo-filtering (HF), the method enhances the affectiv-ity of PIND test about the small particles. In the end, some practical PIND output signals are analysed, and the validity of this new method is proved. 相似文献
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YANG Fen ZHANG Xue-jun TIAN Fang WU Xu GAN Fu-xing 《中国航空学报》2007,20(2):181-186
Antimony-doped tin hydroxide colloid precipitates have been synthesized by hydrolysis of SnCl4 and SbCl3 using: (1) an ion-exchange hydrolysis to remove chlorine ions, and (2) isoamyl acetate as an azeotropic solvent to obviate water. The obtained dried powder is of high dispersivity without any need for further grinding. The size and dispersivity of the final particles are investigated with the aid of TG-DTA, BET, XRD and TEM. After having calcined, the antimony-doped tin oxide nanopowder possesses a tetragonal rutile structure with high dispersivity, uniform particles and low hard agglomeration. 相似文献
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Effects of Mo on the Microstructure and Hydrogen Sorption Properties of Ti-Mo Getters 总被引:1,自引:0,他引:1
ZHOU Hong-guo WEI Xiu-ying MAO Chang-hui XIONG Yu-hua QIN Guang-rong 《中国航空学报》2007,20(2):172-176
The effects of Mo on the microstructure evolution, porosity and hydrogen sorption properties of Ti-Mo getters are investigated in this work. The results show that the addition of Mo prolongs the densification process of Ti-Mo getters and results in a significant amount of sintered pores. With the Mo content increasing, the porosity of getters firstly increases reaching the maximum value as it at- tains about 7.5wt.%, and then drops. At the room temperature, the hydrogen sorption property of getters increases progressively with the Mo content increasing, but the tendency is not very clear before its content lies below 2.5wt.%. When the Mo content achieves about 7.5wt.%, the hydrogen sorption property proves to be the best. The discussion is made about the above mentioned phenomena inclusive of hydrogen sorption properties of getters under different activation conditions (from 500-750 ℃). 相似文献
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超声速燃烧数值模拟中的湍流与化学反应相互作用模型 总被引:1,自引:0,他引:1
高精度数值模拟有助于理解超声速湍流燃烧中湍流与化学反应的相互作用,可为发动机燃烧室等工程应用设计提供可靠的预测模型。除直接数值模拟外,目前在湍流燃烧应用中使用的大涡模拟和雷诺平均Navier-Stokes模拟均需要借助模型模化发生在湍流小尺度上的流动与化学反应过程对湍流大尺度运动的影响。现有的湍流与化学反应相互作用模型大致可分为:火焰面类模型和概率密度函数类模型,2类模型在不同的应用中各自具有优势和局限性。此外,现有模型大都基于低马赫数燃烧,而超声速燃烧中通常会伴随快速混合、局部熄火和再着火以及激波等复杂过程,这为发展其中的湍流与化学反应相互作用模型提出了更多的挑战。 相似文献
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适于低轨卫星IP网络的单核共享树组播算法(英文) 总被引:1,自引:0,他引:1
为了解决低轨卫星IP网络中现有典型源组播算法的信道资源浪费问题,本文提出了一套单核共享树组播算法,即核心群合并共享树(CCST)和加权核心群合并共享树(w-CCST)算法。CCST 算法包括动态近似中心(DAC)选核方法和核心群合并组播路径构建方法。DAC方法专为周期、规律运动的低轨卫星网络提出,不需要复杂的星上计算。在核心群合并方法中,以核节点作为初始核心群,通过核心群和剩余组成员的最短路径方法逐步扩展直至整棵组播树构建完成,从而使得组播树的树代价最小,大大提高了网络的带宽利用率和组播传输效率。w-CCST 算法中所提出的加权因子可以调整树代价和端到端传播时延之间的折衷程度,因此,可以通过调整加权因子来适度增大树代价、降低端到端传播时延以支持某些端到端时延要求苛刻的实时组播业务。最后,与低轨卫星 IP 网络中典型算法进行了性能比较,仿真结果说明,CCST 算法的平均树代价比其它算法显著降低,w-CCST 算法的平均端到端传播时延小于 CCST 算法。 相似文献
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Jet Vectoring Control Using a Novel Synthetic Jet Actuator 总被引:3,自引:1,他引:2
LUO Zhen-bing XIA Zhi-xun XIE Yong-gao 《中国航空学报》2007,20(3):193-201
A primary air jet vectoring control system with a novel synthetic jet actuator (SJA) is presented and simulated numerically. The results show that, in comparison with an existing traditional synthetic jet actuator, which is able to perform the duty of either “push” or “pull”, one novel synthetic jet actuator can fulfill both “push” and “pull” functions to vector the primary jet by shifting a slide block inside it. Therefore, because the new actuator possesses greater efficiency, it has potentiality to replace the existing one in various appli- cations, such as thrust vectoring and the reduction of thermal signature. Moreover, as the novel actuator can fulfill those functions that the existing one can not, it may well be expected to popularize it into more flow control systems. 相似文献
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Nonlinear Adaptive Slewing Motion Control of Spacecraft Truss Driven by Synchronous V-gimbaled CMG Precession 总被引:1,自引:0,他引:1
Zhou Di Zhou Jingyang 《中国航空学报》2007,20(4):332-338
The slewing motion control of a truss arm driven by a V-gimbaled control-moment-gyro (CMG) is a nonlinear control problem. The V-gimbaled CMG consists of a pair of gyros that must precess synchronously. The moment of inertia of the system, the angular momentum of the gyros and the external disturbances are not exactly known. With the help of feedback linearization and recursive Lyapunov design method, an adaptive nonlinear controller is designed to deal with the unknown items. Performance of the proposed controller is verified by simulation. 相似文献
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LI Yue-jun YAN Chao 《中国航空学报》2007,20(3):202-209
A new time-accurate marching scheme for unsteady flow calculations is proposed in the present work. This method is the combination of classical Successive Over-Relaxation (SOR) iteration method and Jacobian matrix diagonally dominant splitting method of LUSGS. One advantage of this algorithm is the second-order accuracy because of no factorization error. Another advantage is the low computational cost because the Jacobian matrices and fluxes are only calculated once in each physical time step. And, the SOR algorithm has better convergence property than Gauss-Seidel. To investigate its accuracy and convergency, several unsteady flow computa- tional tests are carried out by using the proposed SOR algorithm. Roe’s FDS scheme is used to discritize the inviscid flux terms. Un- steady computational results of SOR are compared with the experiment results and those of Gauss-Seidel. Results reveal that the numerical results agree well with the experimental data and the second-order accuracy can be obtained as the Gauss-Seidel for unsteady flow computations. The impact of SOR factor is investigated for unsteady computations by using different SOR factors in this algorithm to simulate each computational test. Different numbers of inner iterations are needed to converge to the same criterion for different SOR factors and optimal choice of SOR factor can improve the computational efficiency greatly. 相似文献