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With the development of electric helicopters’ motor technology and the widespread use of electric drive rotors, more aircraft use electric rotors to provide thrust and directional control. For a helicopter tail rotor, the wake of the main rotor influences the tail rotor’s inflow and wake. In the procedure of controlling, crosswind will also cause changes to the tail disk load. This paper describes requirements and design principles of an electric motor drive and variable pitch tail rotor system. A particular spoke-type architecture of the motor is designed, and the performance of blades is analyzed by the CFD method. The demand for simplicity of moving parts and strict constraints on the weight of a helicopter makes the design of electrical and mechanical components challenging. Different solutions have been investigated to propose an effective alternative to the mechanical actuation system. A test platform is constructed which can collect the dynamic response of the thrust control. The enhancement of the response speed due to an individual motor speed control and variable-pitch system is validated. 相似文献
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可调静子叶片机匣间隙对轴流压气机性能的影响 总被引:1,自引:0,他引:1
多级轴流压气机多采用可调静子调节压气机中低转速性能。由于转动需要,静子叶片与流道间必然存在径向间隙,使得流场中额外引入端壁间隙流。利用CFD软件,研究了可调静子径向间隙对多级轴流压气机性能的影响。相关三维粘性数值仿真结果表明:高精度的CFD分析中,间隙影响不可忽略;可调静子转轴的优化设计,可有效减小间隙对压气机性能的影响。 相似文献
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Experimental Study on Emission Performance of an LPP/TVC 总被引:2,自引:0,他引:2
A key issue in the commercial aircraft engine design is environmental acceptability, and designers are continually challenged to reduce emissions. In this paper, an experimental investigation is performed to evaluate the emission performance of a liquid-fueled trapped vortex combustor (TVC) under lean premixed prevaporized (LPP) mode. When operating as an LPP system, a TVC is fueled both in the cavities and in the main stream. The correlations between the emission performance and the total excess air ratio, the positions (4 positions) of the fuel injectors in the main stream, and the inlet temperature are obtained. Experi- mental results show that both the volume concentrations of unburnt hydrocarbon (UHC) and NOx (NO, NO2 usually grouped together as NOx) increase with the increase of total excess air ratio from 1.5 to 3.0; the emission performance relies heavily on the position of the main stream injector, and the best performance is achieved at Position 4 in the experiments; the increase of the inlet temperature impacts on the emission performance positively; the smallest volume concentrations of UHC and NOx obtained in the experiment are 94×10 6 and 2.3×10 6 respectively. This paper validates the feasibility of low emissions for an LPP/TVC and provides a reference for further optimization of TVCs. 相似文献
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主要介绍了DSP TMS320VC5402芯片并行引导装载的实现方案。对硬件电路设计和配置文件编写过程中的要点作了讨论,并给出了实例。 相似文献
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在基于类别形状函数变换(CST)的反设计方法中,通过考察CST参数化与反设计过程,完成了基于参数敏感性分析的反设计,实现了翼型的快速、准确反设计;研究了Bernstein多项式阶数进化对反设计过程敏感性的影响。研究结果表明,在亚音速状态下,采用反设计方法能使设计压力分布较好逼近目标压力分布;在跨音速状态出现激波时或在计算过程出现迭代发散时,加入阶数进化手段后的敏感性分析方法能改善激波区域的敏感度,使迭代较好收敛。方法能够反映各种光滑翼型压力残差和翼型几何外形改变的关系,在给定状态下用初始翼型快速且比较准确地拟合目标翼型。 相似文献