星形延边三角形接线平衡变压器的阻抗匹配与数学模型

星形延边三角形接线平衡变压器是应用于我国电气化铁道的一种新型三相一两相平衡变压器。针对其特殊的接线形式，提出了以磁势平衡方程、绕组连接方程、端口输出方程和电压传递方程为基础的多绕组变压器系统化分析方法。根据理想平衡变压器的技术条件提出了基于绕组之间短路阻抗的阻抗匹配关系式，推广了以前的有关结论。讨论了星形延边三角形接线平衡变压器的等值模型、两相等值电路和中性点不接地运行等问题。给出了星形延边三角形接线平衡变压器在相坐标下的节点导纳矩阵，以便与电力系统其它部分接口进行有关分析。     

结合定常CFD技术的当地流活塞理论

结合定常CFD技术和超音速非定常气动力工程计算方法——活塞理论，发展了一种基于超音速、高超音速定常流场求解非定常气动力的当地流活塞理论。适用于超音速、高超音速飞机颤振中的小振幅非定常气动力计算。通过与非定常Euler方程求解结果的比较，发现在马赫数不太高或大迎角的超音速流动中，其精度比原始活塞理论高得多，也能够计算超音速、高超音速下大钝头和考虑机身干扰的复杂外形非定常气动力，扩大了活塞理论的应用范围。与非定常Euler方程或N-S方程的数值求解相比，计算效率很高。     

多级离心压缩机无叶扩压器内气动性能的数值研究

对某多级离心压缩机的气动性能进行了整级CFD数值模拟,重点研究并比较了级间与级后无叶扩压器内的气动特点。计算方法基于Jameson格式,湍流模型选择Spalart-Allmaras模型。结果表明,在多级离心压缩机中,无叶扩压器的性能对整个机组的总体性能影响很大。级间与级后无叶扩压器内的能量损失都很高,但后者以摩擦损失为主,而前者由于受其下游弯道的影响,流动发生分离,因而其能量损失来源于摩擦与分离的共同作用。     

A method for the determination of turbulence intensity by means of a fast response pressure probe and its application in a LP turbine

This paper describes the measurements and the post-processing procedure adopted for the determination of the turbulence intensity in a low pressure turbine (LPT) by means of a single sensor fast response aerodynamic pressure probe. The rig was designed in cooperation with MTU Aero Engines and considerable efforts were put into the adjustment of all relevant model parameters. Blade count ratio, airfoil aspect ratio, reduced massflow, reduced speed, inlet turbulence intensity and Reynolds numbers were chosen to reproduce the full scale LP turbine. Measurements were performed adopting a phase-locked acquisition technique in order to provide the time resolved flow field downstream of the turbine rotor. The total pressure random fluctuations are obtained by selectively filtering, in the frequency domain, the deterministic unsteadiness due to the rotor blades and coherent structures. The turbulence intensity is derived from the inverse Fourier transform and the correlations between total pressure and velocity fluctuations. The determination of the turbulence intensity allows the discussion of the interaction processes between the stator and rotor for engine-representative operating conditions of the turbine.     

Structural design of carbon/epoxy bio‐inspired wind turbine blade using fluid/structure simulation

The purpose of this paper is to present the structural design procedure of a low‐speed, horizontal axis, bio‐inspired wind turbine blade made of carbon/epoxy. The methodology initiates with the mechanical characterization of the carbon fiber composite material. An aerodynamic simulation using Computational Fluid Dynamics (CFD) method is performed in order to obtain the pressure distribution profile of the blade. This result is coupled with a Finite Element Analysis (FEA) to carry out an iterative design process through a Fluid‐Structure Interaction (FSI) simulation. Different stacking sequences of laminates are evaluated to find a configuration which allows balance between aerodynamic and dynamic inertial loads, ensuring an almost undeformed geometry during wind turbine's operation. The final structural design of the blade consists in six regions with different laminates. These are balanced and symmetric with distinct thickness characteristics and stacking sequences, which vary in three different orientations: 0^°, ± 45^° and 90^°, achieving a minimum deflection at the tip close to 3.11 cm, and a total weight of 3.6 kg of a 1.8 m radius blade, even with the restrictions imposed by the non‐conventional geometry. Copyright © 2016 John Wiley & Sons, Ltd.     

高温堆燃料元件气动力提升过程的数值模拟

为研究高温气冷堆中燃料球的气动力提升过程，本文采用三维计算流体力学数值模拟与三自由度动力学仿真解耦的方法对燃料球的运动轨迹进行了模拟。通过计算流体力学方法计算了燃料球在提升管内所受的气动力，运用三自由度动力学仿真给出了燃料球在输送管道内的运动轨迹。将数值模拟的运动轨迹与实验测量的结果进行对比发现，本文数值模拟可准确地预测燃料球的运动轨迹和碰撞次数，与实验结果相符。这表明本文方法可用于模拟高温堆燃料球的气动力提升过程。     

Acoustic Resonance in Exhaust Gas Economizer Tube Bundles Prediction and Suppression of Resonance

The tendency for air column resonance generation in structures with a constant volume behind a tube array like that of an exhaust gas economizer has been reported, but many points remain unclear with respect to the mechanism and conditions that generate acoustical resonance. When acoustical resonance is generated, in reality, prevention and suppression measures are implemented by inserting a baffle plate into the ducts through a process of trial and error. The purpose of this study is to clarify the mechanism of generation of acoustical resonance, and to establish an appropriate measure to prevent such resonance. Noise generated in an exhaust gas economizer was correlated with the flow inside the tube array and experimentally analyzed, and the mechanism for resonance generation was considered. In addition, the effectiveness of a baffle plate positioned in order to prevent resonance was investigated. We have successfully employed a single baffle plate to suppress resonance.     

基于分布式控制的某加载试验电气测控系统设计

针对飞机舱门气动加载试验的特点,分析了21个加载通道的测控要求,应用分布式控制方案,采用上下位机结构;选用PCI板卡及合理的调理电路设计,完成了下位机的采集通信功能;上位机中,在labWindows/CVl平台下实现了了监督控制与数据采集,利用多线程机制及多媒体定时器技术,保证了多通道分布式系统中的实时性要求,该电气设计在地面模拟飞行试验中工作良好,充分满足了试验的各项指标要求。     

Weighted Self-Adaptive Threshold Wavelets for Interpolation Point Selection Used in Interconnect MOR

超高膨胀比涡轮噪声控制技术研究

赵辛午，黄洪雁

（哈尔滨工业大学 能源科学与工程学院，哈尔滨 150001）

中文说明：

气动噪声控制是提高鱼雷隐身性能的关键技术之一。本文讨论了局部进气的超高膨胀比涡轮气动噪声产生机理。相邻喷嘴与流道之间形成的三角形非出气区域引起的尾迹、圆周局部进气设计引起的不稳定性、喷嘴和转子之间区域形成的复杂激波系是这类涡轮气动噪声产生的三种主要来源。因此，本文提出了两种气动噪声控制方法，增加转静子之间的轴向间距，喷嘴下俯、双侧修型和尾缘吹气。数值模拟结果表明：在对原涡轮气动性能影响不大的情况下，优化后涡轮的气动噪声下降10 dB以上。

关键词：超高膨胀比涡轮、气动噪声、流动特性、优化

     

基于单个CCCCTA接地回转器的系统综合

为综合基于CCCCTA的接地回转器,根据CCCCTA的零-镜模型和接地回转器的节点导纳矩阵,利用节点导纳矩阵扩展法,我们实现了4个相互等效的接地回转器。导出的回转器具有两个特点,一个是通过调节CCCCTA的偏置电流,可以电控调节回转器的参数; 另一个特点是电路仅使用单个CCCCTA。作为一个例子,通过使用导出的回转器之一,我们实现了一个极点频率为1.274MHz、品质因素为4的带通滤波器。计算机仿真证明所导出的电路正确有效。