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Chernyshev S.L.,Moscow Institute of Physics and Technology | Gaifullin A.M.,Moscow Institute of Physics and Technology | Sviridenko Y.N.,Central Aerohydrodynamic Institute Na Prof Ne Zhukovsky Tsagi
Progress in Aerospace Sciences | Year: 2014

This paper provides a review of research conducted in TsAGI (Central AeroHydrodynamic Institute) concerning a vortex wake behind an airliner. The research into this area of theoretical and practical importance have been done both in Russia and in other countries, for which these studies became a vital necessity at the end of the 20th century. The paper describes the main methods and ratios on which software systems used to calculate the evolution of a vortex wake in a turbulent atmosphere are based. Verification of calculation results proved their acceptable consistency with the known experimental data. The mechanism of circulation loss in a vortex wake which is based on the analytical solution for the problem of two vortices diffusing in a viscous fluid is also described. The paper also describes the model of behavior of an aircraft which has deliberately or unintentionally entered a vortex wake behind another aircraft. Approximated results of calculations performed according to this model by means of artificial neural networks enabled the researchers to model the dynamics of an aircraft in a vortex wake on flight simulators on-line. © 2014 Elsevier Ltd.

Chernyshev S.L.,Central Aerohydrodynamic Institute Na Prof Ne Zhukovsky Tsagi | Zakharchuk V.T.,Central Aerohydrodynamic Institute Na Prof Ne Zhukovsky Tsagi
48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition | Year: 2010

Several properties of the complex spectrum boundary points of the non-Hermitian eigen values problem for matrices are investigated. The algorithm for calculation of eigen values with maximal and minimal real and imaginary part and eigen functions corresponding to these values is proposed. Normally, these eigen values define increment (instability) or decrement (stability). Similar eigen values are also needed while considering merely mathematical problems (e.g. in finite-difference scheme theory and in creation of calculation algorithms). The algorithm proposed is efficient especially for dispersed matrices because it retains matrices dispersity during calculation process. It does not require any initial approximations to eigen values to be found. The results of applying this algorithm to numeric investigation of classical stability problems are given, namely solutions of Poiseuille and Blasius flow problems as a part of boundary eigen values problem for Orr-Sommerfeld equation. © 2010 by the American Institute of Aeronautics and Astronautics, Inc.

Chernyshev S.L.,Central Aerohydrodynamic Institute Na Prof Ne Zhukovsky Tsagi | Kiselev A.P.,Central Aerohydrodynamic Institute Na Prof Ne Zhukovsky Tsagi | Kuryachii A.P.,Central Aerohydrodynamic Institute Na Prof Ne Zhukovsky Tsagi
Progress in Aerospace Sciences | Year: 2011

This paper presents a brief review of activities in laminar flow control being performed at the Central Aerohydrodynamic Institute named after Prof. N.E. Zhukovsky (TsAGI). These efforts are focused on the improvement of the existing laminar flow control methods and on the development of new ones. The investigations have demonstrated the effectiveness of aircraft surface laminarization applications with the aim of friction drag reduction. The opportunity of considerable delaying of laminarturbulent transition due to special wing profile geometry and using boundary layer suction and surface cooling has been verified at sub- and supersonic speeds through various wind tunnel testing at TsAGI and during flying laboratory experiments at the Flight Research Institute (LII). The investigations on using hybrid laminar flow control systems for friction drag reduction were also carried out. New techniques of laminar flow control were proposed, in particular, the method of local heating of the wing leading edge, boundary layer laminarization by means of receptivity control, and electrohydrodynamic methods of boundary layer stability control. © 2010 Elsevier Ltd. All rights reserved.

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