Improvement of conventional combustion chamber structure in order to enhance GTE ecological indicators

The test results of a conventional combustion chamber with the improved structure are presented. The concentration of toxic substance emissions is reduced as compared with combustion chambers of the similar type.     

A technique for selecting a rational variant of a multifunctional aircraft system

A technique for selecting a rational variant of a multifunctional aircraft system using the analytic hierarchy process is proposed and a solution of a practical problem is presented.     

The geostationary orbit and satellite communications: concepts older than commonly supposed

The first proposal for a radio-equipped, man-made satellite in geostationary orbit is customarily attributed to author Arthur Charles Clarke (1917-), however, he makes no claim to having originated the geostationary orbit. Clarke's now classic article, in the October 1945 issue of Wireless World described a system of worldwide broadcasting via three satellites in geostationary orbit. In the article, Clarke listed seven references, including two to previous significant works by Willy Ley (Rockets, first published in 1944) and Hermann Noordung (The Problems of Space Travel, published in 1929). Both these works make reference to the geostationary orbit but as Clarke (see IEEE Spectrum, vol. 31, no.3, p. 4 et seq., Mar. 1994) points out the concept predates these works. It goes back at least to the works of Konstantin Eduardovich Tsiolkovsky (1857-1935), a Russian scientist now regarded as the father of space research. His book, ("Dreams of Earth and Sky"), published in 1895, was the first by a scientist on the subject.     

Amplification of the influence of solar flux variations on the winter stratosphere by planetary waves

Recent observational evidence has suggested that variations in solar activity may affect winter stratospheric polar ozone and temperature levels. The paucity of direct sunlight available during this season points strongly to a dynamical mechanism. We have carried out several large ensemble experiments within the middle atmosphere and the coupled middle atmosphere and lower thermosphere to simulate the radiative/dynamical coupling via planetary waves for a range of solar fluxes. In the former case, the model response in the winter stratosphere was linear and of the order of the summer stratopause forcing, whilst in the latter, the level of correlation in the winter stratosphere remained high, but was diluted over a wider volume. The inclusion of the upper atmosphere enhanced the winter polar stratospheric response by a factor of three.     

Statistical analysis of experimental study results on low-cycle fatigue resistance for the EI698-VD high-temperature alloy

The results of low-cycle fatigue tests of smooth cylindrical specimens made of the EI698-VD nickel-base high-temperature alloy widely used in aircraft engine industry are considered statistically. The influence of such factors as an initial level of mechanical properties, operating time and temperature of tests is evaluated. The experimental data on low-cycle fatigue (LCF) are used when determining the cyclic life for disks.