边界层综合诊断技术研究

给出了对二元翼型模型和三元三角翼模型表面边界层转捩用表面热膜技术、红外热像仪技术和液晶显示技术在同一风洞中同时进行显示和测量并进行比较的结果。对二元NACA-0012翼型表面边界层转捩点位置测量,三种方法都给出了相吻合的结果。三元的60°三角翼模型经过多次实验,测量结果表明表面热膜技术能够给出三角翼模型表面边界层转捩位置的定量侧量结果。红外热像仪技术和液晶显示技术研究在应用时受到环境条件的影响,在合适的条件下也能给出模型表面边界层转捩位置的定量结果。     

Mechanical properties of ANTRIX balloon film and fabrication of single cap large volume balloons

The zero pressure plastic balloons used for high altitude studies are generally made from polyethylene material. Tensile properties of the thin film polymer are the key parameters for material selection due to extremely low temperature of −90 °C encountered by the balloons in the tropopause region during the ascent at equatorial latitudes. The physical and structural properties of the material determine the uniformity of the stress distribution over the entire shell. Load stresses from the suspended load propagate via load tapes heat sealed along with the gore seals as per the balloon design. A balance between this heat seal strength and the film strength is a desirable property of the basic resin in terms of the bubble strength, gauge uniformity, and long-term storage properties. In addition, the design of the top shell of the balloon and its stress distribution play an important role since only a fraction of the balloon is deployed during the filling operation and the ascent. In this paper we describe the mechanical properties of the ‘ANTRIX’ film developed by us and the optimized design of single cap balloons, which have been successfully used in our experiments over the past 5 years.     

ZnO薄膜气敏元件

通过在Al2O3衬底上粉末溅射ZnO做出了气敏特性和稳定性较好的ZnO薄膜气敏元件,实现ZnO薄膜的实用化,表明了ZnO是除SnO2外又一种新的气敏基材料.文中还对ZnO薄膜有关气敏特性和元件的气敏电流IG随酒气浓度C变化的规律进行了介绍.     

Preparation and Microstructure of Highly - Oriented LaNiO3 Thin Films by RF Sputtering Method

In an attempt of being used as buffer layers and electrodes for the textured BaTiO3 （BTO） ferroelectric thin films, highly （100）-oriented LaNiO3 （LNO） thin films of different thicknesses were deposited directly on Si （100） substrate with radio-frequency （RF） magnetron sputtering method. It is observed that the substrate temperatures and the film thicknesses bring main influences on the microstructures and orientation of the thin film. The effects of the thicknesses and substrate temperatures on the orientation of the films were studied on the LNO films of different thicknesses. The highly （100）-oriented LNO thin films were obtained at the substrate temperature of 600℃. The existence of epitaxially grown BTO films indicates that the oriented LNO thin films obtained in this work could be used as a buffer layer for epitaxial growth.     

基于有限元素法的挤压油膜动力特性研究

挤压油膜阻尼器(SFD,Squeeze Film Dumpers)因减振效果显著,目前广泛应用于航空发动机等高速旋转机械中.在基于雷诺方程的短轴承近似解或长轴承近似解基础上,提出了求解带挤压油膜阻尼器的转子支承系统稳态动力特性的有限元挤压油膜计算方法,该方法能有效地模拟转子系统在各种工作条件下的油膜力模型.为了验证上述理论分析结果,用有限元法计算了带挤压油膜阻尼器转子系统的油膜压力分布和油膜阻尼,分析中还考虑了油膜惯性力的影响.通过对某发动机转子支承系统的模拟计算,并与试验结果进行对比分析,证明给出的系统动力特性计算方法及性能分析结果可用于工程实际.      

单排圆柱孔射流气膜加热与气膜冷却方式的对比

为了揭示气膜加热和气膜冷却两种方式在影响规律机制上的异同,通过数值计算研究了两种方式单排圆柱孔在典型吹风比下(0.5,1.0和1.5)的射流-主流相干特征,并分析了热气流-冷气流温度比变化对气膜绝热加热或冷却效率的影响。研究结果表明:在相同的吹风比下,在气膜加热方式下喷注射流向主流的穿透趋向更为显著,引起喷注射流抬离壁面并在气膜孔出口附近诱导出尺度更大的卵形涡对;当温度比接近于1时,气膜绝热加热效率与气膜绝热冷却效率差异较小,随着温度比偏离1的程度加剧,气膜绝热加热效率与气膜绝热冷却效率差异显著增大。     

复杂边界条件下的多层多孔壁温度场的计算模型

经过推导给出了具有孔内和内外表面对流换热及外表面热辐射复杂边界条件下的多层多孔壁温度场的计算模型,并以具有陶瓷隔热涂层的全气膜覆盖气冷叶片为例进行了温度场计算。计算结果表明：陶瓷涂层具有明显的隔热效果,并可明显地减小冷却空气用量;燃气温度对壁温影响较大;考虑热辐射将更加符合实际物理过程;对于涡轮叶片若不考虑热辐射将低估壁温 1. ５％ ～3. ５％ 。该模型可用于多层多孔壁冷却结构形式的发动机高温部件的优化设计。     

Ti-10V-2Fe-3A1合金表面彩色转化膜制取方法及其性能

介绍Ti－10V－2Fe－3A1合金表面彩色转化股的制取工艺及其性能。     

非结构网格生成方法的改进及气膜冷却三维静子流场的求解

讨论五面体网格下,涡轮静子叶片含多排冷却孔时三维粘性流场雷诺平均Navier-Stokes方程组的数值求解问题。考虑到叶片含多排冷却孔的工程背景,本文发展了生成五面体非结构网格的快速有效方法即仅在一个拟S₁面上生成非结构网格,而沿叶高方向仍采用结构网格的生成办法。文中还采用了新的网格优化措施以改善生成网格的质量。流场的计算采用了非结构网格下的高分辨率迎风格式。几个典型算例表明:本文发展的网格生成方法快速有效,而且网格生成质量较高;发展的计算格式能够获得较为满意的三维流场数值解,并具有较高的激波分辨率。