In reality, instead of a constant frontal flame in the combustion zone, a detonation wave is formed, rushing at supersonic speed. In such a compression wave, fuel and oxidizer are detonated, this process, from the point of view of thermodynamics, increases Engine efficiency by an order of magnitude, due to the compactness of the combustion zone.
Interestingly, back in 1940, the Soviet physicist Ya.B. Zel'dovich proposed the idea of a detonation engine in the article "On the energy use detonation combustion". Since then, many scientists from different countries, then the United States, then Germany, then our compatriots came forward.
In the summer, in August 2016, Russian scientists managed to create the world's first full-size liquid-propellant jet engine operating on the principle of detonation combustion of fuel. Our country has finally established a world priority in the development of the latest technology for many post-perestroika years.
Why is the new engine so good? A jet engine uses the energy released by burning a mixture at constant pressure and a constant flame front. During combustion, the gas mixture of fuel and oxidizer sharply increases the temperature and the flame column escaping from the nozzle creates jet thrust.
During detonation combustion, the reaction products do not have time to collapse, because this process is 100 times faster than deflagration and the pressure increases rapidly, while the volume remains unchanged. The allocation of such a large number energy can actually destroy a car engine, which is why such a process is often associated with an explosion.
In reality, instead of a constant frontal flame in the combustion zone, a detonation wave is formed, rushing at supersonic speed. In such a compression wave, fuel and oxidizer are detonated, this process, from the point of view of thermodynamics, increases the efficiency of the engine by an order of magnitude, due to the compactness of the combustion zone. Therefore, experts so zealously began to develop this idea.
In a conventional LRE, which is in fact a large burner, the main thing is not the combustion chamber and nozzle, but the fuel turbopump unit (FPU), which creates such pressure that the fuel penetrates into the chamber. For example, in the Russian RD-170 rocket engine for Energia launch vehicles, the pressure in the combustion chamber is 250 atm and the pump that supplies the oxidizer to the combustion zone has to create a pressure of 600 atm.
In a detonation engine, pressure is created by detonation itself, which represents a traveling compression wave in the fuel mixture, in which the pressure without any TNA is already 20 times greater and turbopump units are superfluous. To make it clear, the American Shuttle has a pressure in the combustion chamber of 200 atm, and the detonation engine in such conditions needs only 10 atm to supply the mixture - this is like a bicycle pump and the Sayano-Shushenskaya hydroelectric power station.
In this case, a detonation-based engine is not only simpler and cheaper by an order of magnitude, but much more powerful and economical than a conventional rocket engine.
On the way to the implementation of the detonation engine project, the problem of co-ownership with the detonation wave arose. This phenomenon is not just a blast wave, which has the speed of sound, but a detonation wave propagating at a speed of 2500 m / s, there is no stabilization of the flame front in it, for each pulsation the mixture is updated and the wave starts again.
Previously, Russian and French engineers developed and built pulsating jet engines, but not on the principle of detonation, but on the basis of ordinary combustion pulsation. The characteristics of such PUVRDs were low, and when engine builders developed pumps, turbines and compressors, the age of jet engines and LREs came, and pulsating ones remained on the sidelines of progress. The bright heads of science tried to combine detonation combustion with a PUVRD, but the frequency of pulsations of a conventional combustion front is no more than 250 per second, and the detonation front has a speed of up to 2500 m/s and its pulsation frequency reaches several thousand per second. It seemed impossible to put into practice such a rate of mixture renewal and at the same time initiate detonation.
In the USA, it was possible to build such a detonation pulsating engine and test it in the air, however, it worked for only 10 seconds, but the priority remained with the American designers. But already in the 60s of the last century, the Soviet scientist B.V. Voitsekhovsky and, almost at the same time, an American from the University of Michigan, J. Nichols, came up with the idea to loop a detonation wave in the combustion chamber.
How a detonation rocket engine works
Such a rotary engine consisted of an annular combustion chamber with nozzles placed along its radius to supply fuel. The detonation wave runs around like a squirrel in a wheel, fuel mixture shrinks and burns out, pushing the products of combustion through the nozzle. In a spin engine, we obtain a wave rotation frequency of several thousand per second, its operation is similar to the working process in a rocket engine, only more efficiently, due to the detonation of the fuel mixture.
In the USSR and the USA, and later in Russia, work is underway to create a rotary detonation engine with a continuous wave to understand the processes occurring inside, and for this a whole science was created - physical and chemical kinetics. To calculate the conditions of an undamped wave, powerful computers were needed, which were created only recently.
In Russia, on a project of such spin engine many research institutes and design bureaus work, including the engine-building company of the space industry NPO Energomash. The Advanced Research Foundation came to help in the development of such an engine, because it is impossible to obtain funding from the Ministry of Defense - they only need a guaranteed result.
Nevertheless, during tests in Khimki at Energomash, a steady state of continuous spin detonation was recorded - 8 thousand revolutions per second on an oxygen-kerosene mixture. At the same time, detonation waves balanced vibration waves, and heat-shielding coatings withstood high temperatures.
But do not flatter yourself, because this is only a demonstrator engine that has worked for a very short time and nothing has yet been said about its characteristics. But the main thing is that the possibility of creating detonation combustion has been proven and a full-sized spin engine has been created in Russia, which will remain in the history of science forever.
Video: Energomash was the first in the world to test a detonation liquid-propellant rocket engine
The publication "Military-Industrial Courier" reports great news from the field of breakthrough missile technologies. A detonation rocket engine has been tested in Russia, Deputy Prime Minister Dmitry Rogozin said on his Facebook page on Friday.
“The so-called detonation rocket engines developed under the program of the Advanced Research Foundation have been successfully tested,” Interfax-AVN quotes the vice-premier.
It is believed that a detonation rocket engine is one of the ways to implement the concept of the so-called motor hypersound, that is, the creation of hypersonic aircraft capable of own engine reach speeds of Mach 4 - 6 (Mach - the speed of sound).
The russia-reborn.ru portal provides an interview with one of the leading specialized engine engineers in Russia about detonation rocket engines.
Interview with Petr Levochkin, chief designer of NPO Energomash named after Academician V.P. Glushko.
Engines for hypersonic missiles of the future are being created
Successful tests of the so-called detonation rocket engines were carried out, which gave very interesting results. Development work in this direction will be continued.
Detonation is an explosion. Can it be made manageable? Is it possible to create hypersonic weapons on the basis of such engines? What rocket engines will take uninhabited and manned vehicles into near space? This was our conversation with the Deputy General Director - Chief Designer of "NPO Energomash named after Academician V.P. Glushko" Petr Levochkin.
Petr Sergeevich, what opportunities do new engines open up?
Petr Levochkin: If we talk about the short term, today we are working on engines for such missiles as the Angara A5V and Soyuz-5, as well as others that are at the pre-design stage and are unknown to the general public. In general, our engines are designed to lift a rocket from the surface of a celestial body. And it can be any - terrestrial, lunar, Martian. So, if the lunar or Martian programs are implemented, we will definitely take part in them.
What is the efficiency of modern rocket engines and are there ways to improve them?
Petr Levochkin: If we talk about energy and thermodynamic parameters engines, it can be said that ours, as well as the best foreign chemical rocket engines today, have reached a certain perfection. For example, the completeness of fuel combustion reaches 98.5 percent. That is, almost all the chemical energy of the fuel in the engine is converted into thermal energy of the outgoing gas jet from the nozzle.
Engines can be improved in many ways. This includes the use of more energy-intensive fuel components, the introduction of new circuit designs, and an increase in pressure in the combustion chamber. Another direction is the use of new, including additive, technologies in order to reduce labor intensity and, as a result, reduce the cost. rocket engine. All this leads to a decrease in the cost of output payload.
However, upon closer examination, it becomes clear that increasing the energy characteristics of engines in the traditional way is ineffective.
Using a controlled propellant explosion could give a rocket a speed eight times the speed of sound
Why?
Petr Levochkin: Increasing pressure and fuel consumption in the combustion chamber will naturally increase engine thrust. But this will require an increase in the thickness of the walls of the chamber and pumps. As a result, the complexity of the structure and its mass increase, and the energy gain turns out to be not so great. The game will not cost the candle.
That is, rocket engines have exhausted the resource of their development?
Petr Levochkin: Not really. Speaking technical language, they can be improved by increasing the efficiency of intra-motor processes. There are cycles of thermodynamic conversion of chemical energy into the energy of an outflowing jet, which are much more efficient than the classical combustion of rocket fuel. This is the detonation combustion cycle and the Humphrey cycle close to it.
The very effect of fuel detonation was discovered by our compatriot - later Academician Yakov Borisovich Zeldovich back in 1940. Realization of this effect in practice promised very great prospects in rocket science. It is not surprising that the Germans in those same years actively investigated the detonation process of combustion. But they did not advance further than not entirely successful experiments.
Theoretical calculations have shown that detonation combustion is 25 percent more efficient than the isobaric cycle, which corresponds to fuel combustion at constant pressure, which is implemented in the chambers of modern liquid-propellant engines.
And what provides the advantages of detonation combustion in comparison with the classical one?
Petr Levochkin: The classic combustion process is subsonic. Detonation - supersonic. The speed of the reaction in a small volume leads to a huge heat release - it is several thousand times higher than in subsonic combustion, implemented in classical rocket engines with the same mass of burning fuel. And for us engine engineers, this means that with a much smaller detonation engine and with a small mass of fuel, you can get the same thrust as in modern huge liquid rocket engines.
It is no secret that engines with detonation combustion of fuel are also being developed abroad. What are our positions? We yield, we go at their level or we are in the lead?
Petr Levochkin: We are not inferior - that's for sure. But I can’t say that we are in the lead either. The topic is fairly closed. One of the main technological secrets is how to ensure that the fuel and oxidizer of a rocket engine does not burn, but explodes, without destroying the combustion chamber. That is, in fact, to make a real explosion controllable and manageable. For reference: detonation is the combustion of fuel in the front of a supersonic shock wave. There are pulsed detonation, when the shock wave moves along the axis of the chamber and one replaces the other, as well as continuous (spin) detonation, when the shock waves in the chamber move in a circle.
As far as we know, experimental studies of detonation combustion have been carried out with the participation of your specialists. What results have been obtained?
Petr Levochkin: Work was done to create a model chamber for a liquid detonation rocket engine. Under the patronage of the Foundation for Advanced Study, a large cooperation of leading scientific centers Russia. Among them, the Institute of Hydrodynamics. M.A. Lavrentiev, MAI, "Keldysh Center", Central Institute of Aviation Motors. P.I. Baranov, Faculty of Mechanics and Mathematics, Moscow State University. We proposed to use kerosene as a fuel, and gaseous oxygen as an oxidizing agent. In the process of theoretical and experimental studies, the possibility of creating a detonation rocket engine based on such components was confirmed. Based on the data obtained, we have developed, manufactured and successfully tested a model detonation chamber with a thrust of 2 tons and a pressure in the combustion chamber of about 40 atm.
This task was solved for the first time not only in Russia, but also in the world. So, of course, there were problems. Firstly, they are connected with the provision of stable detonation of oxygen with kerosene, and secondly, with the provision of reliable cooling of the fire wall of the chamber without curtain cooling and a host of other problems, the essence of which is clear only to specialists.
Can a detonation engine be used in hypersonic missiles?
Petr Levochkin: It is both possible and necessary. If only because the combustion of fuel in it is supersonic. And in those engines on which they are now trying to create controlled hypersonic aircrafts, subsonic combustion. And this creates a lot of problems. After all, if the combustion in the engine is subsonic, and the engine flies, say, at a speed of Mach 5 (one Mach equal to speed sound), it is necessary to slow down the oncoming air flow to sound mode. Accordingly, all the energy of this deceleration is converted into heat, which leads to additional overheating of the structure.
And in a detonation engine, the combustion process occurs at a speed of at least two and a half times higher than the sound speed. And, accordingly, we can increase the speed of the aircraft by this amount. That is, we are already talking not about five, but about eight swings. This is the currently achievable speed of aircraft with hypersonic engines, which will use the principle of detonation combustion.
Petr Levochkin: This is complex issue. We have just opened the door to the area of detonation combustion. There is still a lot of unexplored left outside the brackets of our study. Today, together with RSC Energia, we are trying to determine how the engine as a whole with a detonation chamber may look in the future in relation to upper stages.
On what engines will a person fly to distant planets?
Petr Levochkin: In my opinion, we will be flying on traditional LRE for a long time, improving them. Although, of course, other types of rocket engines are also developing, for example, electric rocket engines (they are much more efficient than rocket engines - their specific impulse is 10 times higher). Alas, today's engines and launch vehicles do not allow us to talk about the reality of massive interplanetary, and even more so intergalactic flights. So far, everything is at the level of fantasy: photon engines, teleportation, levitation, gravitational waves. Although, on the other hand, just a little over a hundred years ago, the writings of Jules Verne were perceived as pure fantasy. Perhaps a revolutionary breakthrough in the area where we work is not far away. Including in the field of practical creation of rockets using the energy of an explosion.
Dossier "RG":
"Scientific and Production Association Energomash" was founded by Valentin Petrovich Glushko in 1929. It now bears his name. Here they develop and produce liquid rocket engines for the I, in some cases II stages of launch vehicles. The NPO has developed more than 60 different liquid-propellant jet engines. The first satellite was launched on Energomash engines, the first man flew into space, the first self-propelled vehicle Lunokhod-1 was launched. Today, more than ninety percent of launch vehicles in Russia take off on engines designed and manufactured by NPO Energomash.
At the end of January, there were reports of new successes in Russian science and technology. From official sources it became known that one of the domestic projects of a promising detonation-type jet engine has already passed the testing stage. This brings the moment of complete completion of all the required work, as a result of which space or military rockets Russian development will be able to get new power plants with improved performance. Moreover, the new principles of engine operation can be applied not only in the field of rockets, but also in other areas.
In the last days of January, Deputy Prime Minister Dmitry Rogozin told the domestic press about the latest successes of research organizations. Among other topics, he touched upon the process of creating jet engines using new operating principles. A promising engine with detonation combustion has already been brought to the test. According to the Deputy Prime Minister, the use of new principles of operation of the power plant makes it possible to obtain a significant increase in performance. In comparison with the designs of traditional architecture, there is an increase in thrust of about 30%.
Diagram of a detonation rocket engine
Modern rocket engines different classes and types operated in various areas use the so-called. isobaric cycle or deflagration combustion. In their combustion chambers, a constant pressure is maintained, at which the fuel burns slowly. An engine based on deflagration principles does not need particularly strong units, but is limited in maximum performance. Increasing the main characteristics, starting from a certain level, turns out to be unreasonably difficult.
An alternative to an isobaric cycle engine in the context of performance enhancement is a system with a so-called. detonation combustion. In this case, the fuel oxidation reaction occurs behind the shock wave, with high speed moving through the combustion chamber. This places special demands on the design of the engine, but at the same time offers obvious advantages. In terms of fuel combustion efficiency, detonation combustion is 25% better than deflagration combustion. It also differs from combustion with constant pressure by an increased heat release rate per unit surface area of the reaction front. In theory, it is possible to increase this parameter by three to four orders of magnitude. As a result, the speed of reactive gases can be increased by 20-25 times.
Thus, the detonation engine, characterized by an increased coefficient useful action, capable of developing greater traction with less fuel consumption. Its advantages over traditional designs are obvious, but until recently, progress in this area left much to be desired. The principles of a detonation jet engine were formulated as early as 1940 by the Soviet physicist Ya.B. Zeldovich, but finished products of this kind have not yet reached operation. The main reasons for the lack of real success are problems with creating a sufficiently strong structure, as well as the difficulty of launching and subsequently maintaining a shock wave using existing fuels.
One of the latest domestic projects in the field of detonation rocket engines was launched in 2014 and is being developed at NPO Energomash named after V.I. Academician V.P. Glushko. According to the available data, the purpose of the project with the Ifrit cipher was to study the basic principles new technology with the subsequent creation of a liquid rocket engine using kerosene and gaseous oxygen. The new engine, named after the fire demons from Arab folklore, was based on the principle of spin detonation combustion. Thus, in accordance with the main idea of the project, the shock wave must continuously move in a circle inside the combustion chamber.
The lead developer of the new project was NPO Energomash, or rather, a special laboratory created on its basis. In addition, several other research and design organizations were involved in the work. The program received support from the Advanced Research Foundation. By joint efforts, all participants of the Ifrit project were able to form an optimal image promising engine, as well as to create a model combustion chamber with new principles of operation.
To study the prospects of the whole direction and new ideas, a so-called. a model detonation combustion chamber that meets the requirements of the project. Such an experimental engine with a reduced configuration was supposed to use liquid kerosene as a fuel. Gaseous oxygen was proposed as the oxidizing agent. In August 2016, testing of the experimental chamber began. It is important that for the first time in a project of this kind it was possible to bring it to the stage of bench tests. Previously, domestic and foreign detonation rocket engines were developed, but not tested.
In the course of testing a model sample, it was possible to obtain very interesting results showing the correctness of the approaches used. So, by using the right materials and technologies turned out to bring the pressure inside the combustion chamber to 40 atmospheres. The thrust of the experimental product reached 2 tons.
Model camera on the test bench
Within the framework of the Ifrit project, certain results were obtained, but the domestic liquid-fuel detonation engine is still far from full-fledged practical application. Before introducing such equipment into new technology projects, designers and scientists will have to decide whole line the most serious tasks. Only after that, the rocket and space industry or the defense industry will be able to start realizing the potential of new technology in practice.
In the middle of January Russian newspaper”published an interview with the chief designer of NPO Energomash, Petr Levochkin, the topic of which was the current state of affairs and the prospects for detonation engines. The representative of the enterprise-developer recalled the main provisions of the project, and also touched upon the topic of the successes achieved. In addition, he spoke about the possible areas of application of Ifrit and similar structures.
Eg, detonation engines can be used in hypersonic aircraft. P. Levochkin recalled that the engines now proposed for use in such equipment use subsonic combustion. At hypersonic speed of the flight apparatus, the air entering the engine must be slowed down to the sound mode. However, the braking energy must lead to additional thermal loads on the airframe. In detonation engines, the fuel burning rate reaches at least M=2.5. This makes it possible to increase the flight speed of the aircraft. Such a machine with a detonation-type engine would be able to accelerate to speeds eight times the speed of sound.
However, the real prospects for detonation-type rocket engines are not too great yet. According to P. Levochkin, we "have just opened the door to the area of detonation combustion." Scientists and designers will have to study many issues, and only after that it will be possible to create structures with practical potential. Because of this, the space industry will have to use traditional liquid-propellant engines for a long time, which, however, does not negate the possibility of their further improvement.
An interesting fact is that detonation principle combustion finds application not only in the field of rocket engines. Already exists domestic project aviation system with a detonation-type combustion chamber operating on the pulse principle. A prototype of this kind was brought to the test, and in the future it may give rise to a new direction. New engines with detonation combustion can find application in a variety of fields and partially replace gas turbine or turbo jet engines traditional designs.
The domestic project of a detonation aircraft engine is being developed at the OKB. A.M. Cradles. Information about this project was first presented at last year's international military-technical forum "Army-2017". At the stand of the enterprise-developer there were materials on various engines, both serial and under development. Among the latter was a promising detonation sample.
The essence of the new proposal is the use of a non-standard combustion chamber capable of carrying out pulsed detonation combustion of fuel in an air atmosphere. In this case, the frequency of "explosions" inside the engine should reach 15-20 kHz. In the future, an additional increase in this parameter is possible, as a result of which the engine noise will go beyond the range perceived by the human ear. Such features of the engine may be of particular interest.
The first launch of an experimental product "Ifrit"
However, the main advantages of the new power plant are associated with improved performance. Bench tests of experimental products showed that they are about 30% superior to traditional gas turbine engines in terms of specific performance. By the time of the first public demonstration of materials on the OKB engine. A.M. Cradles could get and quite high performance characteristics. An experimental engine of a new type was able to work for 10 minutes without interruption. The total operating time of this product at the stand at that time exceeded 100 hours.
Representatives of the developer indicated that it is already possible to create a new detonation engine with a thrust of 2-2.5 tons, suitable for installation on light aircraft or unmanned aerial vehicles. In the design of such an engine, it is proposed to use the so-called. resonators responsible for right move fuel combustion. An important advantage new project is the fundamental possibility of installing such devices anywhere in the airframe.
Specialists of OKB im. A.M. The cradles are working on aircraft engines with pulsed detonation combustion for more than three decades, but so far the project has not left the research stage and has no real prospects. main reason– lack of order and necessary financing. If the project receives the necessary support, then in the foreseeable future a sample engine suitable for use on various vehicles can be created.
To date, Russian scientists and designers have managed to show very remarkable results in the field of jet engines using new operating principles. There are several projects at once suitable for use in the rocket-space and hypersonic fields. In addition, new engines can be used in "traditional" aviation. Some projects are still in their early stages and not yet ready for inspections and other work, while in other areas the most remarkable results have already been obtained.
Exploring the subject of jet engines with detonation combustion, Russian specialists were able to create a bench model of a combustion chamber with the desired characteristics. The Ifrit prototype has already been tested, during which a large amount of various information was collected. With the help of the received data, the development of the direction will continue.
Mastering a new direction and translating ideas into a practically applicable form will take a lot of time, and for this reason, in the foreseeable future, space and army rockets in the foreseeable future will be equipped only with traditional liquid engines. Nevertheless, the work has already left the purely theoretical stage, and now each test run of an experimental engine brings closer the moment of building full-fledged missiles with new power plants.
According to the websites:
http://engine.space/
http://fpi.gov.ru/
https://rg.ru/
https://utro.ru/
http://tass.ru/
http://svpressa.ru/
Why is the new engine so good? A jet engine uses the energy released by burning a mixture at constant pressure and a constant flame front. During combustion, the gas mixture of fuel and oxidizer sharply increases the temperature and the flame column escaping from the nozzle creates jet thrust.
During detonation combustion, the reaction products do not have time to collapse, because this process is 100 times faster than deflagration and the pressure increases rapidly, while the volume remains unchanged. The release of such a large amount of energy can actually destroy a car engine, which is why such a process is often associated with an explosion.
In reality, instead of a constant frontal flame in the combustion zone, a detonation wave is formed, rushing at supersonic speed. In such a compression wave, fuel and oxidizer are detonated, this process, from the point of view of thermodynamics, increases the efficiency of the engine by an order of magnitude, due to the compactness of the combustion zone. Therefore, experts so zealously began to develop this idea.
In a conventional LRE, which is in fact a large burner, the main thing is not the combustion chamber and nozzle, but the fuel turbopump unit (FPU), which creates such pressure that the fuel penetrates into the chamber. For example, in the Russian RD-170 rocket engine for Energia launch vehicles, the pressure in the combustion chamber is 250 atm and the pump that supplies the oxidizer to the combustion zone has to create a pressure of 600 atm.
In a detonation engine, pressure is created by detonation itself, which represents a traveling compression wave in the fuel mixture, in which the pressure without any TNA is already 20 times greater and turbopump units are superfluous. To make it clear, the American Shuttle has a pressure in the combustion chamber of 200 atm, and the detonation engine in such conditions needs only 10 atm to supply the mixture - this is like a bicycle pump and the Sayano-Shushenskaya hydroelectric power station.
In this case, a detonation-based engine is not only simpler and cheaper by an order of magnitude, but much more powerful and economical than a conventional rocket engine.
On the way to the implementation of the detonation engine project, the problem of co-ownership with the detonation wave arose. This phenomenon is not just a blast wave, which has the speed of sound, but a detonation wave propagating at a speed of 2500 m / s, there is no stabilization of the flame front in it, for each pulsation the mixture is updated and the wave starts again.
Previously, Russian and French engineers developed and built pulsating jet engines, but not on the principle of detonation, but on the basis of ordinary combustion pulsation. The characteristics of such PUVRDs were low, and when engine builders developed pumps, turbines and compressors, the age of jet engines and LREs came, and pulsating ones remained on the sidelines of progress. The bright heads of science tried to combine detonation combustion with a PUVRD, but the frequency of pulsations of a conventional combustion front is no more than 250 per second, and the detonation front has a speed of up to 2500 m/s and its pulsation frequency reaches several thousand per second. It seemed impossible to put into practice such a rate of mixture renewal and at the same time initiate detonation.
In the USA, it was possible to build such a detonation pulsating engine and test it in the air, however, it worked for only 10 seconds, but the priority remained with the American designers. But already in the 60s of the last century, the Soviet scientist B.V. Voitsekhovsky and, almost at the same time, an American from the University of Michigan, J. Nichols, came up with the idea to loop a detonation wave in the combustion chamber.
Such a rotary engine consisted of an annular combustion chamber with nozzles placed along its radius to supply fuel. The detonation wave runs like a squirrel in a wheel around the circumference, the fuel mixture is compressed and burned out, pushing the combustion products through the nozzle. In a spin engine, we obtain a wave rotation frequency of several thousand per second, its operation is similar to the working process in a rocket engine, only more efficiently, due to the detonation of the fuel mixture.
In the USSR and the USA, and later in Russia, work is underway to create a rotary detonation engine with a continuous wave, to understand the processes occurring inside, for which a whole science of physical and chemical kinetics was created. To calculate the conditions of an undamped wave, powerful computers were needed, which were created only recently.
In Russia, many research institutes and design bureaus are working on the project of such a spin engine, including the engine-building company of the space industry NPO Energomash. The Advanced Research Foundation came to help in the development of such an engine, because it is impossible to obtain funding from the Ministry of Defense - they only need a guaranteed result.
Nevertheless, during tests in Khimki at Energomash, a steady state of continuous spin detonation was recorded - 8 thousand revolutions per second on an oxygen-kerosene mixture. At the same time, detonation waves balanced vibration waves, and heat-shielding coatings withstood high temperatures.
But do not flatter yourself, because this is only a demonstrator engine that has worked for a very short time and nothing has yet been said about its characteristics. But the main thing is that the possibility of creating detonation combustion has been proven and a full-size engine has been created in Russia, which will remain in history forever.
Detonation engine tests
FPI_RUSSIA / Vimeo
The specialized laboratory "Detonation LRE" of the Energomash Research and Production Association tested the world's first full-size detonation liquid-propellant rocket engine technology demonstrators. According to TASS, the new power plants run on an oxygen-kerosene fuel pair.
The new engine, unlike other power plants operating on the principle internal combustion, operates due to the detonation of the fuel. Detonation is the supersonic combustion of a substance this case fuel mixture. In this case, a shock wave propagates through the mixture, followed by a chemical reaction with the release of a large amount of heat.
The study of the principles of operation and the development of detonation engines has been carried out in some countries of the world for more than 70 years. The first such work began in Germany in the 1940s. True, the researchers failed to create a working prototype of a detonation engine at that time, but pulsating jet engines were developed and mass-produced. They were placed on V-1 rockets.
In pulsating jet engines, fuel burned at subsonic speeds. This combustion is called deflagration. The engine is called pulsating because fuel and oxidizer were fed into its combustion chamber in small portions at regular intervals.
Pressure map in the combustion chamber of a rotary detonation engine. A - detonation wave; B - trailing front of the shock wave; C - mixing zone of fresh and old combustion products; D - fuel mixture filling area; E is the region of the non-knocking burnt fuel mixture; F - expansion zone with detonated burnt fuel mixture
Detonation engines today are divided into two main types: impulse and rotary. The latter are also called spin. The principle of operation of impulse motors is similar to that of pulsating motors. jet engines. The main difference lies in the detonation combustion of the fuel mixture in the combustion chamber.
Rotary detonation engines use an annular combustion chamber in which the fuel mixture is fed sequentially through radial valves. In such power plants, detonation does not fade - the detonation wave “runs around” the annular combustion chamber, the fuel mixture behind it has time to be updated. Rotary engine first began to be studied in the USSR in the 1950s.
Detonation engines are capable of operating in a wide range of flight speeds - from zero to five Mach numbers (0-6.2 thousand kilometers per hour). It is believed that such power plants can produce more power, consuming less fuel than conventional jet engines. At the same time, the design of detonation engines is relatively simple: they lack a compressor and many moving parts.
All detonation engines tested so far have been developed for experimental aircraft. Tested in Russia power point is the first designed to be mounted on a rocket. What type of detonation engine was tested is not specified.
