高、低能扰动力函数对叶轮机阵发非定常气动力的影响(英文)

为了研究扰动力函数对多级叶轮机叶片排中基本的高、低能阵发非定常气动响应的影响,在研究用轴流压气机上进行了一系列的基础研究。      

TRANSIENT AERODYNAMIC BEHAVIOURS ASSOCIATED WITH STEPWISE INCIDENCE VARIATION OF AIRFOILS

Transient aerodynamic characteristics of airfoil are important for the safety of airplanes, the development of helicopter rotors and many other applications of unsteady aerodynamics. For a better understanding of these phenomena, it is necessary to investigate the simultaneous relation between the characteristics and the flow field. The purpose of the present study is to clarify experimentally the fundamentals of the aerodynamic behaviours associated with stepwise incidence variations from 0 to some certain values, including high angles of attack, of symmetric airfoils at low speeds, Reynolds number being of the order of 104. Temporal variations of surface pressure distribution, lift, drag and . pitching moment, and the observation of the flow field will be discussed.     

SEPARATED FLOW AROUND BENT-NOSE BICONIC IN HYPERSONIC FLOW

This article investigates the separated flow around the bent-nose biconic, in which the second ordered TVD(Total Variation Diminishing) method is applied. The governing cqua-tion is a thin layer Navier-Stokes equation. The surface pressure distribution at the leeward side is a little higher in the vicinity of the symmetrical plane. This seems to be caused by the development of the vortex at the leeward side due to the separated flow. The location of a separation line and the size are in very good agreement with the experiment. Also the secondary separation is captured very clearly.     

OPTICAL TELEPHONE CORD PASSING THROUGH LONG PIPE WITH SPIRAL FLOW

A new effective technique, useful in telecommunications industry for passing an optical telephone cord attached to a connector through pipeline,has been developed using the spiral flow. Using this technique, the cord could be passed through a straight pipeline 150 meters long and a roll of vinyl tube 50 meters long. However, under the same condition, the cord could not pass through when using the turbulent flow. To obtain a high speed stable spiral flow, a nozzle with an annular slit connected to a conical cylinder was used. A pressurized fluid with no tangential flow was supplied through this slit and the fluid, passing through the conical cylinder, was deformed into spiral flow with the steeper axial velocity distribution compared to that of turbulence pipe flow due to Coanda effect and instability. As a result, the cord was attracted to the axis area of the pipe, which effectively increased the ability for the work of cord passing. This high ability for cord passing is attributed mainly to the reduct     

STRATOSPHERIC LIGHTER-THAN-AIR POWERED PLATFORM

A feasibility study has been carried out on a high altitude (20km) superpressurcd PLTA(powered lighter-than-air) platform, which has a long service life and larger payload than that of a large artificial satellite. This PLTA platform has an electric propulsion system to cope with wind flow for position keeping and its thruster is driven by solar power acquired through solar cells. Solar energy is to be stored for night use in regenerative fuel cells. The study is focused on energy balance and hull structure analysis of the platform. This platform is particularly capable of conducting high resolution remote sensing and telecommunications relay. This platform can replace a number of ground-based telecommunications relay facilities and can guarantee reasonable radio frequency intensity enough to secure good telecommunications quality. The altitude where the platform resides is the least windy area in the lower stratosphere at a height from which one can have a direct line of sight on the ground within a 1,     

摆动磨削和强力(蠕动进给)磨削方法的发展现状和应用可能性

为了使平面和型面磨削这种方法的应用更广泛、更有效和更经济早在五十年代的中期,Edmund Lang 就已集中了一些助手,从事于寻找进行平面和型面磨削新方法的可能性。即利用一种新型机床,它既能达到当时在铣床上所能达到的切削效率,同时也能达到一般磨削所能达到的精度。在当时现有的经验基础上作进一步发展,有可能在一定的前提和考虑到一些影响因素(磨轮、驱动功率、机器设计)的情况下实现这     

飞行模拟的准直显示

本文叙述了目视飞行模拟器在显示方面的限制,表明了准直显示的要求。给出了获得飞行模拟准直显示法广泛研究的结果以及继之发展的“睹飞”(Duo-view)显示,从座舱各部分看,它都给出了不变形的显示。本文叙述了这种显示系统并指出了它的性能。     

光学薄膜的特性

本文研究介质薄膜的各种特性:折射率和吸收系数、光散射、结构、显微结构、密度、气体吸收、化学成分、均匀度、附着力、硬度和机械应力、环境影响。Ⅰ、前言适当地选择折射率、薄膜厚度和膜层数目,可以设计出各种通常是很复杂的光学薄膜,这种薄膜设计,要在工业上得以实现,是需要足够数量的高质量镀膜材料,经过处理之后,使薄膜有适当的复现特性。尽管在过去几年中材料科学和镀膜技术有显著的进展,但遗憾的是适合的材料数目仍然有限。单层薄膜的主要介质材料的基本光学性质的研究是 Hass     

计算流体动力学的问题范围及最新发展

1、引言本文是关于计算流体动力学问题范围和最新发展的译述。所谓“最新”是相对于我的书(Roache,1972)而言的。(为简短起见,那本书在本文中称为 CFD。本文里的有些课题在 CFD 中已提及但强调得不够,而其余的在写那本书时尚未出现。