Kazan State Technical University of A.N. Tupolev’s name (KAI)

Karl Marx str., 10, Kazan, Russia

e-mail: perel@kai.ru

The researches of air accidents in the airport zones accompanying with cases of sudden failures or explosions of engines, show, that in the nearest neighborhood of a place of a catastrophe the stack of nearest steam power plant or large boiler-house is situated, as a rule (Irkutsk, 1997, crush during take-off of airplane " Ruslan " is, China, 1998, crush of airplane TU-134 owing to explosion of engines at a landing approach etc.).

The scientific version of the author is that at hit of gas depleted by oxygen from the mentioned stacks in the air engine the combustion chamber puts out.

According to the rules of operations at dieting out of the combustion chamber it is necessary to switch off fuel supply in the engine. Otherwise, the feeding fuel partially evaporates, partially fills up various pockets and there begins to boil, so during some time the explosive mixture will be derived. The switch on of ignition in such situation inevitably will come to explosion or, at the best, to a clap, which, in turn, will put out of the camera. On the other hand, there is not time for disconnecting fuel supply, blow-down of an engine and lighting up of the combustion chamber. Thus one from the probable reasons of a catastrophe is a hit in a engine inert (poor oxygen) gas.

According to book of R.S. Scorer “Environmental Aerodynamics” (Halsted Press, 1978) at the outlet from these stacks can be formed following smoke whiffes: wavy, conic, fan-shaped, smoked, ascending, bifurcated, termic forming. The last represent rather steady formations of large portions of smoke (yields of combustion, in which the oxygen practically is absent). Bifurcated formations are adjoin to them, they differ from termics by fresh air that penetrates inside, and two homogeneous on a structure but not intermixed during some time cylindrical termics will be formed. They also represent large danger for aviation engines.

It is possible to add also, that at unsatisfactory grounding of airplane with a working engine on ground the static charge is stored on it reducing to forming potential difference in 1,0 - 1,5kV. The static charge is born by an exhaust jet also, that can promote the form of rather steady aerosol structures of exhaust gases. It is impossible to eliminate, that in this case the formation of bifurcated termics also is possible. For example, in article of O.Favorsky, A. Starick “Atmosphere of the Earth and Aircraft: the problems and research tasks” (Actual problems of aviation and aerospace systems: processes, models, experiment; Kazan – Daytona Beach, No.1, 1998) can be found data of a debris flow. The learning of problems of amount of the charged particles and their influence to formation of aerosols is the extremely actual task.

In this connection it is represented expedient to make a complex research on a strict mathematical basis of behavior of the engine in the given situation and to work out the concept for system engineering of automatic control ensuring safety of flight. The solution of the similar task is possible on the basis of designed program complexes GRAD, POTOK created in KSTU-KAI. At use of these tools the finishing of a mathematical model of an engine is necessary for the description of processes of a boiling and evaporation of air kerosene on hot details of an engine at the dieting out combustion chamber.

Besides the numerical experiment with simulation of air composition feeding in an engine, with researching of an engine response is necessary. It will allow, in particular, to define a structure of monitoring of air pool in a neighborhood of the airports, the necessity in which is already obvious. The author is ready to make the full complex of researches, with the building of strong mathematical model, with the elaboration of corresponding algorithm for engines control system with the aim: to ensure the safety flight regime.

B.Kh.Perelstein, Dr., Principal Researcher; he is the author more than 100 scientific works, 30 inventions; scientific interests area is problems of mathematical modelling, the non-stable thermodynamics; the processes in gas-turbine engines, in gas-turbine plants.

http://www.kai.ru/people/perelshtein.dh.