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211.
随着高速、超高速轨道交通的快速发展,需要发展新型的风洞设备,实现风洞性能和试验能力的突破.磁浮飞行风洞是利用真空管道列车概念结合动模型试验技术提出的一种新概念风洞设备,可以构建出更加接近真实状态的测试环境.本文从磁浮飞行风洞基本概念、国内外研究现状及发展趋势、试验技术、应用需求等几个方面开展论述.首先论述了国内外传统风洞和动模型设备的现状及发展趋势,指出了发展磁浮飞行风洞的必要性;其次,重点对磁浮飞行风洞需要发展的试验技术进行了分析;最后,对磁浮飞行风洞在超高速轨道交通及其他领域的应用需求进行了展望. 相似文献
212.
C. Mahesh Satya Prakash V. SathiyamoorthyR.M. Gairola 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
In this paper, an improved Kalpana-1 infrared (IR) based rainfall estimation algorithm, specific to Indian summer monsoon region is presented. This algorithm comprises of two parts: (i) development of Kalpana-1 IR based rainfall estimation algorithm with improvement for orographic warm rain underestimation generally suffered by IR based rainfall estimation methods and (ii) cooling index to take care of the growth and decay of clouds and thereby improving the precipitation estimation. 相似文献
213.
N. I. Akishev I. I. Zakirov V. A. Ivanov V. N. Paimushin M. A. Shishov 《Russian Aeronautics (Iz VUZ)》2011,54(2):115-124
The known analytical solutions of the linearized stability problems for rectangular hinged plates under the combined loading
are generalized to the similar problems for skew plates, the deformation mechanics of which is described by the equations
of the classical theory formed in the oblique Cartesian coordinates. 相似文献
214.
In this paper, we examine experimentally some devices the principle of action of which is based on using the dynamic pressure
of air extracted to engine cooling and which are meant for reducing the radial temperature gradient in GTE rotor disks. We
established that the devices equipped with the ejector channels make it possible to accelerate the process of the disk hub
heating by hot air suction from the cavity periphery towards the rotor axis of rotation. Using the data of visualization studies,
we show the possibility for efficient operation of ejector devices in the conditions of real GTE rotor circumferential velocities. 相似文献
215.
A technique of optimizing the electrode system of the differential recorder for the aircraft time-of-flight ion-marking airspeed
and aircraft angle of attack sensor by the criterion of ion-marking recording error variance minimum is considered. The technique
is based on analyzing the function of spatial distribution for the ion-marking and recorder electrode interaction field potential
and determining a point for which this function reaches the maximum slope. The relations making it possible to synthesize
the sensor electrode system by the complex criterion as a ratio of error variance to transformation channel response are obtained. 相似文献
216.
The basic steps of an algorithm are given for calculating the parameters of the limiting state of a helicopter main rotor
blade. To estimate the static strength, a technique of elastic constants variation is used; it is based on the limit equilibrium
theory and enables us to obtain the upper and lower bounds for the critical load simultaneously. An iterative technique is
proposed to determine the lower bound of the allowable load on the root section of the composite blade depending on the azimuthal
angle of its turn in the helicopter hovering mode. 相似文献
217.
A technique of analyzing the flutter initiation in flat plate compressor cascades was developed. The viscous and inviscid
flow study was carried out using the COBRA solver based on the modified implicit Godunov method and unsteady implicit method
updated for using. The flutter conditions were revealed and the effect of taking into account viscosity, angles of attack
and time steps was investigated. 相似文献
218.
V. A. Futin 《Russian Aeronautics (Iz VUZ)》2011,54(2):165-169
The influence of the clearance between the case and blade ends of the semi-open impeller on the centrifugal stage characteristics
is considered using the experimental data and numerical calculation results. 相似文献
219.
The influence of geometry and operating conditions of the centrifugal compressor stage on the radial gas force is determined
on the basis of the theoretical method and calculation program using experimental boundary conditions. 相似文献
220.
M. V. Usanin A. A. Siner A. M. Sipatov L. Yu. Gomzikov V. G. Avgustinovich 《Russian Aeronautics (Iz VUZ)》2011,54(1):34-42
The application of the low dissipative high-order accurate scheme for numerical solution of the Euler and Navier-Stokes equations
in the two-dimensional statement is considered. The scheme of calculating space derivatives is the seven-point central-difference
approximation of the fourth order with the coefficients optimized to reduce the dispersion errors. The optimized six-step
Runge-Kutta method is used for evaluating the time derivatives. By means of filtration, spurious pulsations are suppressed
and shocks are processed. The results of verifying the calculation scheme realized on the stationary problem of flow around
the model turbine blades are presented. 相似文献