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Review on Numerical and Experimental Research on Conventional and Unconventional Propeller Blade Design 常规与非常规螺旋桨叶片设计数值与实验研究综述
Pub Date : 2017-04-30 DOI: 10.15866/IREASE.V10I2.11547
H. A. Kutty, P. Rajendran
This paper reviews the research conducted on propeller blades based on the performance evaluation method and available design. The review includes the propeller blades used for aircrafts, unmanned aerial vehicles, marine vehicles and wind turbines, as the working principle remain the same, differing only in operating conditions. Both experimental and numerical methods were discussed to provide a reliable procedure to investigate the performance of propeller blades. In addition, the propeller blades design was discussed, including conventional and unconventional blade designs. Blade shape, chord length and twist angle are the basic parameters for optimization method on conventional design. Optimization managed to improve propeller performance at an impressive rate. Many designs are currently being developed allowing more possibilities for blade design advancement.
本文综述了基于性能评价方法和可用设计的螺旋桨叶片研究。该审查包括用于飞机,无人机,船舶和风力涡轮机的螺旋桨叶片,因为工作原理保持不变,只是在操作条件上有所不同。为了提供一种可靠的研究螺旋桨叶片性能的方法,对实验方法和数值方法进行了探讨。此外,还讨论了螺旋桨叶片的设计,包括常规叶片设计和非常规叶片设计。叶片型、弦长和扭角是常规设计优化方法的基本参数。优化设法以令人印象深刻的速度提高螺旋桨性能。许多设计目前正在开发允许更多的可能性叶片设计进步。
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引用次数: 7
Spatiotemporal Analysis for NDVI Time Series Using Local Binary Pattern and Daubechies Wavelet Transform 基于局部二值模式和小波变换的NDVI时间序列时空分析
Pub Date : 2017-04-30 DOI: 10.15866/irease.v10i2.11873
Bachir Kaddar, H. Fizazi
NDVI time series has shown to be very efficient for vegetation change dynamic analysis over a long period. However, noise and illumination variations present significant challenges to perform an accurate change detection. This paper aims at capturing global vegetation change dynamics within 16-days MODIS-NDVI time series by considering the inter-annual variations. To determine the appropriate scale that characterizes the long term variation, an efficient way relying on wavelet transform is used. First, the Daubechies 4 wavelet transform is employed to perform a multi-scale decomposition to extract the inter-annual variations and remove noise. Second, critical point theory is used to identify a set of points indicating potential vegetation change within time series, which, allows a time series reduction. Then, for each critical point, LBP code is computed to characterize the corresponding local patterns, which provides the ability to deal with illumination variations. Based on the extracted features, a change map is produced by computing similarity between neighboring time series, assessing dynamic vegetation change over the period of study. Experiment results using NDVI time series show clearly the potential of the proposed approach to detect change.
NDVI时间序列对长期植被变化动态分析非常有效。然而,噪声和光照变化对执行准确的变化检测提出了重大挑战。本文旨在通过考虑年际变化,捕捉全球16天MODIS-NDVI时间序列的植被变化动态。为了确定表征长期变化的合适尺度,采用了一种基于小波变换的有效方法。首先,采用Daubechies 4小波变换进行多尺度分解,提取年际变化,去除噪声;其次,利用临界点理论在时间序列内识别一组指示潜在植被变化的点,从而实现时间序列缩减。然后,对于每个临界点,计算LBP代码以表征相应的局部模式,从而提供处理光照变化的能力。基于提取的特征,通过计算相邻时间序列之间的相似度生成变化图,评估研究期间植被的动态变化。使用NDVI时间序列的实验结果清楚地显示了该方法检测变化的潜力。
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引用次数: 2
High-Temperature Starter-Generator with Fractional-Slot Concentrated Windings for More Electric Aircraft: Design and Testing of the Scaled-Size Prototype 多电飞机用分数槽集中绕组高温起动发电机:按比例样机的设计与试验
Pub Date : 2017-04-30 DOI: 10.15866/IREASE.V10I2.12038
F. Ismagilov, V. Vavilov, N. Tarasov, V. Ayguzina
This paper presents the design and experimental research of a scaled-size prototype of the high-temperature starter-generator for more electric aircrafts. A computer model of the prototype with a high accuracy and good convergence with the experimental results was designed. In addition, the cooling efficiency evaluation was carried out; the losses in starter-generator active parts were estimated. Based on the results of experimental research and computer simulation, the full-size starter-generator was designed. It is important to notice that the full-size starter-generator was less loaded in terms of electromagnetic and thermal loads. This shows the proposed method efficiency. The obtained mass properties of the full-sized starter-generator is less than the 10 kg Thales’ starter-generator. This proves the efficiency of the researched variant.
本文介绍了多电飞机用高温起动发电机按比例样机的设计与实验研究。设计了精度高、与实验结果收敛性好的样机计算机模型。此外,还进行了冷却效率评价;估计了起动器-发电机有功部分的损耗。在实验研究和计算机仿真的基础上,设计了全尺寸起动发电机。值得注意的是,全尺寸起动发电机在电磁和热负荷方面的负荷较小。验证了该方法的有效性。得到的全尺寸起动发电机的质量特性小于泰雷兹公司的10公斤起动发电机。这证明了所研究的变体的有效性。
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引用次数: 1
Increasing Energy Parameters of High-Speed Magneto-Electric Generator for Autonomous Objects 提高自主目标高速磁电发电机能量参数
Pub Date : 2017-04-30 DOI: 10.15866/IREASE.V10I2.11708
F. Ismagilov, I. Khayrullin, V. Vavilov, V. Bekuzin, V. Ayguzina
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引用次数: 2
In the loop simulator for the verification of small space platforms 在循环模拟器中对小空间平台进行验证
Pub Date : 2017-04-30 DOI: 10.15866/IREASE.V10I2.10593
F. Stesina, S. Corpino, L. Feruglio
The paper presents an end-to-end simulator aimed at supporting the engineering team in the design and verification activity across the whole product life cycle. The simulator is devoted to the analysis of small space systems, which present specific features if compared to large traditional platforms. Improving the understanding of the system early in the life cycle, and enhancing the verification process may help to increase the reliability and mission success of small-scale satellites while maintaining their key features of low cost and fast delivery. The simulator is designed through a Model and Simulation Based approach and allows performing "in-the-loop simulations" for the verification of functional and operational requirements at component, subsystem, and system level. The simulator is characterized by a modular architecture to adapt to several missions and different system configurations, also outside the space field. The core of the tool is a multi-processor workstation that sets up and runs the simulation, making use of a models database for the equipment and the mission environment, and a built-in interface unit to connect all the elements. The simulator has been successfully tested on a CubeSat project. Many test sessions were run and they are described into the detail in this article.
本文提出了一个端到端的模拟器,旨在支持工程团队在整个产品生命周期中的设计和验证活动。该模拟器专门用于分析小型空间系统,与大型传统平台相比,这些系统呈现出特定的特征。在生命周期早期提高对系统的了解,并加强验证过程,可能有助于提高小型卫星的可靠性和任务成功率,同时保持其低成本和快速交付的关键特征。该模拟器是通过基于模型和仿真的方法设计的,允许在组件、子系统和系统级别执行“环内仿真”,以验证功能和操作需求。该模拟器的特点是采用模块化架构,以适应多个任务和不同的系统配置,也适用于太空领域之外。该工具的核心是一个多处理器工作站,用于设置和运行仿真,利用设备和任务环境的模型数据库,以及连接所有元素的内置接口单元。该模拟器已在CubeSat项目上成功测试。运行了许多测试会话,本文将对它们进行详细描述。
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引用次数: 7
An EKF Based Method for Path Following in Turbulent Air 湍流空气中基于EKF的路径跟踪方法
Pub Date : 2017-02-28 DOI: 10.15866/IREASE.V10I1.10501
C. Grillo, F. Montano
An innovative use of the Extended Kalman Filter (EKF) is proposed to perform both accurate path following and adequate disturbance rejection in turbulent air. The tuned up procedure employs simultaneously two different EKF: the first one estimates gust disturbances, the second one estimates modified aircraft parameters. The first filter, by using measurements gathered in turbulent air, estimates both aircraft states and wind components. The second one, by using the estimated disturbances, obtains command laws that are able to reject disturbances. The predictor of the second EKF uses the estimated wind components to solve motion equations in turbulent air. Besides a set of unknown stability and control parameters (containing displacements of the controls) is introduced into the predictor. This set contains modified aerodynamic coefficients. These ones are obtained by adding entirely new derivatives or synthetic increments to basic ones. Therefore, the above aforementioned unknown values of aircraft parameters augment the aircraft’s state. The filter estimates the augmented state by using a set of measurements formed by the desired flight path variables. In this way, it is possible to obtain the command laws by using the postulated unknown stability and control derivatives, which contain the control displacements. Therefore, the obtained control laws, related to either the characteristics of the disturbance or the desired flight path, are adaptive.
提出了扩展卡尔曼滤波(EKF)的一种创新应用,在湍流空气中实现精确的路径跟踪和足够的干扰抑制。调整过程同时采用两种不同的EKF:第一个估计阵风干扰,第二个估计修改后的飞机参数。第一个过滤器,通过使用在湍流空气中收集的测量数据,估计飞机状态和风的成分。第二种方法是利用估计的扰动,得到能够抑制扰动的指令律。第二次EKF的预报器使用估计的风分量来求解湍流空气中的运动方程。此外,在预测器中引入了一组未知的稳定性和控制参数(包含控制器的位移)。这一组包含修正的空气动力系数。这些是通过在基本的衍生物上添加全新的衍生物或合成增量而得到的。因此,上述飞机参数的未知值增强了飞机的状态。该滤波器通过使用由期望的飞行路径变量组成的一组测量值来估计增强状态。这样,就可以利用假设的未知稳定性和包含控制位移的控制导数来获得命令律。因此,所得到的控制律,无论是与扰动的特性还是与期望的飞行路径有关,都是自适应的。
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引用次数: 4
Integrated High-Temperature Starter-Generator for Aerospace Vehicles. Testing of a Scaled-Size Prototype 用于航天飞行器的集成高温起动-发生器。按比例大小的原型测试
Pub Date : 2017-02-28 DOI: 10.15866/IREASE.V10I1.11034
V. Vavilov
The main purpose of this article is to perform experiments on a scaled model of the SG on HPS with permanent magnets, a teeth winding and an outer rotor at temperature of up to 2200С to analyze its electromechanical characteristics. On the basis of these researches, it is possible to create and verify the computer model in Ansys Maxwell which allows linear scaling of SG dimensions to design a SG with higher capacity. This paper also deals with the application efficiency research of different types of high-temperature wires (including copper conductor and nickel conductors). It helps to choose the best variant for the SG with HPS. Changings on losses in a high-temperature SG with a rise in temperature is analyzed as well. On the basis of research results the conclusion on practicality of the suggested concept and the SG structural design are given. The novelty of the paper is that the experimental research results of the high-temperature SG on HPS with a teeth winding and an outer rotor at a temperature of 2200С is being published for the first time. The conclusion on the integration of the SG into HPSs are being given based on the researches.
本文的主要目的是在温度高达2200С的情况下,在带有永磁体、齿形绕组和外转子的HPS上进行SG的比例模型实验,分析其机电特性。在这些研究的基础上,可以在Ansys Maxwell中创建并验证计算机模型,该模型允许对SG尺寸进行线性缩放,从而设计出更高容量的SG。本文还对不同类型高温导线(包括铜导体和镍导体)的应用效率进行了研究。它有助于选择最好的变型与HPS的SG。分析了高温SG中损耗随温度升高的变化规律。在研究结果的基础上,给出了建议概念的实用性和SG结构设计的结论。本文的新颖之处在于首次发表了高温SG在温度为2200С的齿形绕组外转子HPS上的实验研究结果。在研究的基础上,提出了SG集成到hps中的结论。
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引用次数: 4
A Dual-Level Hybrid Approach for Classification of Satellite Images 一种双级混合卫星图像分类方法
Pub Date : 2017-02-28 DOI: 10.15866/irease.v10i1.11191
Mustapha Si Tayeb, H. Fizazi
The traditional methods for extracting information from satellite images are generally based on the spectral response of the sensors. These approaches are in some cases insufficient in particular in case of high-resolution images. In fact these images have a spectral content increasingly heterogeneous. It is, therefore, necessary to use more efficient analysis methods. The multi-source classification is a robust analytical tool, and it is one of the most used approaches for the extraction of telemetric information. This paper is focused on the problem of the classification of satellite images by the hybridization of several methods: multi-layer perceptron, hidden Markov models and genetic algorithms. The results prove the efficiency of the proposed final approach, with a classification rate of 98.79%, significantly higher respect to the results obtained by the MLP method, and by other approaches.
从卫星图像中提取信息的传统方法通常是基于传感器的光谱响应。这些方法在某些情况下是不够的,特别是在高分辨率图像的情况下。事实上,这些图像的光谱含量越来越不均匀。因此,有必要采用更有效的分析方法。多源分类是一种鲁棒的分析工具,是遥测信息提取中最常用的方法之一。本文研究了多层感知器、隐马尔可夫模型和遗传算法相结合的卫星图像分类问题。结果证明了该方法的有效性,分类率为98.79%,明显高于MLP方法和其他方法的分类率。
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引用次数: 0
Justification Possibilities of Removing Man-Made Objects from the Earth's Orbit Using Inflatable Structures 论证利用充气结构将人造物体移出地球轨道的可能性
Pub Date : 2017-02-28 DOI: 10.15866/IREASE.V10I1.10848
V. M. Kulkov, V. V. Terentyev, S. O. Firsyuk
In this paper, the problem of clearing up low-Earth orbit from the man-made space debris is considered. For this purpose the variants of released in space inflatable ballutes (IB) are proposed. A set of mathematical models and systems of equations, sufficient to evaluate the requirements for the design of the spacecraft equipped with IB, is formed. For an object with a low mass (about 20 kg, which corresponds to a small spacecraft) the calculation of the basic parameters for this orbit is carried out and the results for four different initial attitudes are shown. Finally the requirements for the design and characteristics of the IB materials are described.
本文研究了近地轨道人造空间碎片的清除问题。为此,提出了空间释放充气ballutes (IB)的改型。形成了一套数学模型和方程系统,足以评估配备IB的航天器的设计要求。对于小质量物体(约20kg,对应于小型航天器),进行了该轨道基本参数的计算,并给出了四种不同初始姿态的计算结果。最后阐述了IB材料的设计要求和特点。
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引用次数: 0
3D Backward-Facing Step Flow Structure Modification with Plasma Actuators 用等离子体作动器修正三维后向阶跃流动结构
Pub Date : 2017-02-28 DOI: 10.15866/IREASE.V10I1.10491
A. J. Torres, R. Bardera-Mora, Mario Sánchez García, M. Calero
Backward-Facing Step (BFS) shape is a common configuration found in several engineering applications. The turbulent flow structure in the backside of a BFS leads to risky situations. Then, flow control is a useful technique to achieve safe conditions. In recent years, plasma devices have become an interesting technology with high importance for flow control because of non-moving parts, fast time response and low energy consumption. This paper presents the experimental investigation of a set of Dielectric Barrier Discharge (DBD) plasma actuators placed on the rounded edge of a BFS and its capability for flow control by wind tunnel testing. In contrast to the other studies, the behaviour of the plasma actuators in presence of 3D flow over a BFS was investigated. Firstly, a parametric study by analysing the location and the influence of the electrical parameters of the DBD plasma actuator was performed at a freestream velocity of 6 m/s using Particle Image Velocimetry (PIV). It was seen that actuator with -45° wall jet provides the highest flow control at 30 kVpp and 2.5 kHz with a reattachment length reduction of 65.6% referred to plasma off case. This configuration was optimized and compared with a double actuator for a higher velocity (10 m/s). The manufacturing complexity of the double actuator recommends the use of a simple actuator due to the fact that they have similar results, with a 30% of reattachment point reduction approximately at 10 m/s. Anyhow, the results confirm the authority of plasma actuators to modify the flow structure behind a BFS.
后向台阶(BFS)形状是在许多工程应用中发现的常见配置。BFS尾部的紊流结构会导致危险情况的发生。因此,流量控制是实现安全条件的有效技术。近年来,等离子体器件因其无运动部件、时间响应快、能耗低等特点,在流体控制中具有重要的应用价值。本文通过风洞试验,研究了一组介质阻挡放电(DBD)等离子体致动器放置在BFS圆角边缘的实验结果及其控制流动的能力。与其他研究相反,研究了等离子体致动器在BFS上存在三维流动时的行为。首先,利用粒子图像测速技术(PIV)对自由流速度为6 m/s的DBD等离子体作动器进行了参数化研究,分析了电参数的位置和影响。结果表明,采用-45°壁面射流的执行器在30 kVpp和2.5 kHz时提供了最高的流量控制,在等离子体关闭情况下,再连接长度减少了65.6%。对该配置进行了优化,并与更高速度(10 m/s)的双驱动器进行了比较。由于双致动器的制造复杂性,建议使用简单的致动器,因为它们具有相似的结果,在大约10米/秒的速度下,再附着点减少30%。无论如何,结果证实了等离子体作动器在改变BFS后流动结构方面的权威。
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引用次数: 2
期刊
International Review of Aerospace Engineering
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