There was held a round table "Planes and Engines of the Future" in the RAS SB Institute of Theoretical and Applied Mechanics named after S. Khristianovich in June 2007. More than 70 leading national scientists and specialists, guests from Germany participated in its work. Discussions were dedicated to prospects of flying machines, prime trends of development of fundamental and applied research in aviation and space industries.

Reports of academicians Viktor Panin (Institute of Physics of Strength and Materials Science, Tomsk) and Alexander Rebrov (Institute of Thermal Physics named after S. Kutateladze, Novosibirsk), other prominent Siberian scientists roused great interest. They covered a wide range of problems - from creation of nanostructural materials to their practical application, from laser technologies of metal cutting to welding, from assessment of expenditures on construction of aircraft to description of environmental problems.

Heated debates developed in the course of discussion of possibilities to use aerodynamic and stands for ground modeling of elements of perspective aircraft and aerospace engines. It is common knowledge that this approach is inefficient in terms of hypersonic flying speed. In our case it is based on mathematical methods. And modern computers are able to forecast main parameters and characteristics of the plane with a high precision level sufficient for engineering needs.

Certainly, hypersonic aircraft are largely developed on the basis of specific tests. They are carried out to check up effectiveness of proposed physical and mathematical methods as a result of which it becomes possible to appreciate mechanisms of interaction of air streams with a plane, solve many special problems arising in the course of design and tests of machines. By the way, it is not a simple task to reproduce original parameters of a hypersonic flight. It is impossible to maintain high temperatures (some thousand degrees) and intense pressure (up to thousands of atms) in ground-based devices for a long time. And then aerodynamic pipes of short-term action with a working interval of some milliseconds (and even microseconds!) come to the rescue. Development of time-saving measurement methods and high-performance computer complexes allow not only to collect huge volumes of information, but also to process it.

Of course, when creating experimental devices, a lot of difficulties can emerge. In particular, it is very difficult to bring a required quantity of energy into a stream. Scientists consider different methods of warming up this stream: use of heavy pistons to compress it rapidly and, thus, increase the temperature, laser radiation energy, magneto-hydrodynamic devices, electrical discharges of high capacity, etc.

The alternative way of considered experiment consists in application of ballistic routes, when the model is fired at a required speed into a long (some hundred meters) tube. In the course of this flight scientists measure its aerodynamic parameters.

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However, even at low speeds aerodynamic pipes can give a lot of useful information, which is very important for modern commercial aircraft. But in this case it is necessary to increase their working parts by some tens of meters. But implementation of relevant projects require significant investments and expenses, which is too much for one country. That is why intergovernmental working groups and committees are now being set up.

Participants of the "round table" took special note of the problem of modeling promising aviation engines - prime phase of construction of hypersonic flying vehicles gaining 5 - 15 sound velocities and more. To achieve this goal, it is necessary to develop a radically new ram jet engine, which would use atmospheric air as an oxidizer. But to implement this idea in practice, it is difficult, first, to reduce the air speed before it gets into the combustion chamber; second, it is difficult to mix fuel and oxidizer and achieve complete combustion of inflammable mixture. Figuratively speaking, scientists have not only to kindle a match in the strong wind, but also bring this process to the end. Nevertheless, specialists are now considering different principles of operation of such engines. They have proved that their potentialities can be substantially extended via application of nonpermanent processes of enhancement of efficiency of the combustion chamber. Another attractive offer - creation of the engine running on a continuous wave detonation.

At the same time, one should remember that hypersonic ram jet engines under consideration are limited in speed and flying height. Besides, it is reasonable to apply two-stage constructions to bring these engines into outer

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space: the first stage - a plane with the specified engine, the second stage - a recoverable vehicle with a rocket engine (this principle was applied in the American demonstrator X-43 - a small model about 4 m long, whose flight lasted for about 12 seconds). But it cost some hundred million dollars to create this machine.

In a word, the "round table" participants made the following conclusion: in order to come to grips with this challenge - to use aircraft with hypersonic units, they have to cooperate with specialists from different countries. And the most promising way to solve this problem is to integrate efforts of the European Union and Russia.

Scientists and specialists who gathered in Novosibirsk in summer 2007 also discussed the problem of increase of life of flying machines. In many respects, the problem lies in a technology of production of proper components of aircraft. At the present time they are all-welded, produced by means of a laser, which often results in a destruction of a metal structure near the welding seam; there is also lack of information on its endurance strength. Many specialists believe that it is possible to improve reliability of connections by way of combination of different methods of power supply to the seam (ultrasound, cold plasma, electron flow) and use of nanotechnologies. Besides, application of nanostructural coatings will allow to prolong the life of aircraft components.

One more pressing problem is reduction of noise from engines and structural elements of flying vehicles. Blast waves, accompanying flight of supersonic aircraft, are detrimental not only to buildings near airports (broken window glasses), but also to all living souls along its route. Moreover, high-speed passenger planes affect ecological situation; their flight is accompanied by dangerous exhausts into the atmosphere, destruction of the Earth's ozone layer and formation of toxic oxides.

But planes are interesting for people not only because of their high speeds and huge tonnage. At present minor aviation, including homemade machinery, becomes more and more popular. In this case the major problem is safety of such vehicles. Microaircraft*, constructed on the basis of nanotechnologies, seem exotic to the majority of people, although can be used in many ways: environmental monitoring, monitoring of safety of buildings, control over air composition, condition of forest areas, etc.

As a whole, many participants of the "round table" believe that a comprehensive approach to the problem of creation of any aeroplane is extremely important. It is necessary to consider it as a living organism. And, it will respond by improving our life and making it more comfortable.

A. Maskov, "Aircraft and Engines of the Future", "Science in Siberia", No. 25, 2007

Prepared by Yaroslav SIBIRTSEV

* See: Ye. Sokolov, "Microaircraft", Science in Russia, No. 3, 2006. - Ed.