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 it so good new engine? 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 engine efficiency by an order of magnitude, due to the compactness of the combustion zone. Therefore, experts so zealously set about developing this idea. In a conventional rocket engine, which is essentially a large burner, the main thing is not the combustion chamber and nozzle, but the fuel turbopump unit (TNA), which creates such pressure that 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. The problem of co-control with a detonation wave arose on the way to implementing the detonation engine project. 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 came jet engines and LRE, and pulsating 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, 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 spin engine it is in Russia that will remain in the history of science forever.
LLC "Analog" was organized in 2010 for the production and operation of the design of sprayers invented by me for fields, the idea of which is fixed by the RF Patent for utility model No. 67402 in 2007.
Now, I have developed a concept rotary internal combustion engine, in which it is possible to organize detonation (explosive) combustion of incoming fuel with an increased release (by about 2 times) of pressure and temperature energy of exhaust gases while maintaining engine performance. Accordingly, with an increase, approximately 2 times, the efficiency heat engine, i.e. up to about 70%. The implementation of this project requires large financial costs for its design, selection of materials and production of a prototype. And in terms of characteristics and applicability, this is an engine, most of all, aviation, and also quite applicable for cars, self-propelled equipment etc., i.e. is necessary at the present stage of development of technology and environmental requirements.
Its main advantages will be simplicity of design, efficiency, environmental friendliness, high torque, compactness, low level noise even without a muffler. Copy protection will be its high manufacturability and special materials.
The simplicity of the design is ensured by its rotary design, in which all parts of the engine perform a simple rotational movement.
Environmental friendliness and efficiency are ensured by 100% instantaneous combustion of fuel in a durable, high-temperature (about 2000 g C), uncooled, separate combustion chamber, which is closed for this time by valves. Cooling of such an engine is provided from the inside (cooling of the working fluid) with any portions of water necessary for this, entering the working section before firing the next portions of the working fluid (combustion gases) from the combustion chamber, while obtaining additional water vapor pressure and useful work on the working shaft.
High torque even at low speeds is provided (compared to a piston ICE) by a large and constant size shoulder of the impact of the working fluid on the working blade. This factor will allow for any land transport do without a complex and expensive transmission, or at least significantly simplify it.
A few words about its design and operation.
The internal combustion engine has a cylindrical shape with two rotor-vane sections, one of which serves to inlet and pre-compress the fuel-air mixture and is a well-known and efficient section of a conventional rotary compressor; the other, working, is a modernized rotary steam engine Marcinevsky; and between them there is a static array of durable heat-resistant material, in which there is a separate, lockable for the duration of combustion, combustion chamber with three non-rotating valves, 2 of which are free, according to the petal type, and one is controlled to relieve pressure before inlet of the next portion of the fuel assembly.
When the engine is running, the working shaft with rotors and blades rotates. In the inlet section, the blade sucks in and compresses the fuel assembly and, when the pressure increases above the pressure of the combustion chamber (after depressurizing it) working mixture is driven into a hot (about 2000 gr C) chamber, ignited by a spark, instantly explodes. Wherein, inlet valve closes, opens Exhaust valve, and before opening it is injected into the working section required amount water. It turns out that super-hot gases are shot into the working section under high pressure, and there a portion of water, which turns into steam and the vapor-gas mixture, sets the engine rotor in rotation, while cooling it. According to available information, there is already a material that can withstand temperatures up to 10,000 ° C for a long time, from which a combustion chamber must be made.
In May 2018, an Application for an invention was filed. The application is currently under consideration on the merits.
This application for investment is submitted to secure funding for R & D, the creation of a prototype, its fine-tuning and tuning until a working sample is obtained. this engine. This process may take a year or two. Funding options for further development of engine modifications for various equipment can and should be developed separately for its specific samples.
additional information
The implementation of this project is a test of the invention by practice. Getting a working prototype. The resulting material can be offered to the entire domestic engineering industry for the development of models Vehicle with an efficient internal combustion engine based on contracts with the developer and payment of commission fees.
You can choose your own, the most promising direction for the design of internal combustion engines, for example, aircraft engine building for ALS and offer a manufactured engine, as well as install this internal combustion engine on own development SLA, the prototype of which is under assembly.
It should be noted that the private jet market in the world has just begun to develop, while in our country it is in its infancy. And, incl. namely, the lack of a suitable internal combustion engine hinders its development. And in our country, with its endless expanses, such aviation will be in demand.
Market Analytics
The implementation of the project is the receipt of a fundamentally new and extremely promising internal combustion engine.
Now the emphasis is on ecology, and as an alternative piston internal combustion engine an electric motor is proposed, but this energy necessary for it needs to be generated somewhere, accumulated for it. The lion's share of electricity is generated at thermal power plants, which are far from environmentally friendly, which will lead to significant pollution in their locations. And the service life of energy storage devices does not exceed 2 years, where to store this harmful trash? The result of the proposed project is an effective and harmless and, no less important, convenient and familiar internal combustion engine. Just need to fill low grade fuel into the tank.
The result of the project is the prospect of replacing all piston engines in the world with this one. This is the prospect of using the powerful energy of the explosion for peaceful purposes, and constructive solution for this process in ICE is proposed for the first time. What's more, it's relatively inexpensive.
Project uniqueness
This is an invention. Design that allows the use of detonation in the engine internal combustion offered for the first time.
At all times, one of the main tasks in the design of internal combustion engines was to approach the conditions of detonation combustion, but not to allow its occurrence.
Monetization channels
Sale of licenses for the right to manufacture.
1The problem of development of rotary detonation engines is considered. The main types of such engines are presented: the Nichols rotary detonation engine, the Wojciechowski engine. The main directions and trends in the development of the design of detonation engines are considered. It is shown that modern concepts of a rotary detonation engine cannot, in principle, lead to the creation of a workable design that surpasses the existing jet engines in terms of its characteristics. The reason is the desire of designers to combine wave generation, fuel combustion, and fuel and oxidizer ejection into one mechanism. As a result of self-organization of shock-wave structures, detonation combustion is carried out in a minimum rather than maximum volume. The result actually achieved today is detonation combustion in a volume not exceeding 15% of the volume of the combustion chamber. The way out is seen in a different approach - first, an optimal configuration of shock waves is created, and only then fuel components are fed into this system and optimal detonation combustion is organized in a large volume.
detonation engine
rotary detonation engine
Wojciechowski engine
circular detonation
spin detonation
impulse detonation engine
1. B. V. Voitsekhovsky, V. V. Mitrofanov, and M. E. Topchiyan, Structure of the detonation front in gases. - Novosibirsk: Publishing House of the USSR Academy of Sciences, 1963.
2. Uskov V.N., Bulat P.V. On the problem of designing an ideal diffuser for compressing a supersonic flow // Basic Research. - 2012. - No. 6 (part 1). - S. 178-184.
3. Uskov V.N., Bulat P.V., Prodan N.V. The history of the study of irregular reflection of a shock wave from the symmetry axis of a supersonic jet with the formation of a Mach disk // Fundamental Research. - 2012. - No. 9 (part 2). - S. 414-420.
4. Uskov V.N., Bulat P.V., Prodan N.V. Justification of the application of the stationary Mach configuration model to the calculation of the Mach disk in a supersonic jet // Fundamental research. - 2012. - No. 11 (part 1). – S. 168–175.
5. Shchelkin K.I. Instability of combustion and detonation of gases // Uspekhi fizicheskikh nauk. - 1965. - T. 87, no. 2.– S. 273–302.
6. Nichols J.A., Wilkmson H.R., Morrison R.B. Intermittent Detonation as a Trust-Producing Mechanism // Jet Propulsion. - 1957. - No. 21. - P. 534-541.
Rotary detonation engines
All types of rotary detonation engines (RDE) have in common that the fuel supply system is combined with the fuel combustion system in the detonation wave, but then everything works like in a conventional jet engine - a flame tube and a nozzle. It was this fact that initiated such activity in the field of modernization gas turbine engines(GTE). It seems attractive to replace only the mixing head and the mixture ignition system in the gas turbine engine. To do this, it is necessary to ensure the continuity of detonation combustion, for example, by launching a detonation wave in a circle. Nichols was one of the first to propose such a scheme in 1957, and then developed it and conducted a series of experiments with a rotating detonation wave in the mid-1960s (Fig. 1).
By adjusting the diameter of the chamber and the thickness of the annular gap, for each type of fuel mixture, it is possible to choose such a geometry that detonation will be stable. In practice, the relationship between the gap and the diameter of the engine turns out to be unacceptable, and it is necessary to control the speed of wave propagation by controlling the fuel supply, as discussed below.
As with pulse detonation engines, the circular detonation wave is capable of ejecting oxidizer, allowing RDE to be used at zero speeds. This fact led to a flurry of experimental and computational studies of RDE with an annular combustion chamber and spontaneous ejection. fuel-air mixture, to list here which does not make any sense. All of them are built approximately according to the same scheme (Fig. 2), reminiscent of the Nichols engine scheme (Fig. 1).
Rice. 1. Scheme of organization of continuous circular detonation in the annular gap: 1 - detonation wave; 2 - a layer of "fresh" fuel mixture; 3 - contact gap; 4 - an oblique shock wave propagating downstream; D is the direction of the detonation wave
Rice. 2. Typical circuit RDE: V - free flow velocity; V4 - flow rate at the outlet of the nozzle; a - fresh fuel assemblies, b - detonation wave front; c - attached oblique shock wave; d - combustion products; p(r) - pressure distribution on the channel wall
A reasonable alternative to the Nichols scheme could be the installation of a plurality of fuel-oxidation injectors that would inject a fuel-air mixture into the region immediately before the detonation wave according to a certain law with a given pressure (Fig. 3). By adjusting the pressure and the rate of fuel supply to the combustion region behind the detonation wave, it is possible to influence the rate of its propagation upstream. This direction is promising, but the main problem in the design of such RDEs is that the widely used simplified model of the flow in the detonation combustion front does not correspond to reality at all.
Rice. 3. RDE with controlled fuel supply to the combustion area. Wojciechowski rotary engine
The main hopes in the world are associated with detonation engines operating according to the scheme rotary engine Voitsekhovsky. In 1963 B.V. Voitsekhovsky, by analogy with spin detonation, developed a scheme for continuous combustion of gas behind a triple configuration of shock waves circulating in an annular channel (Fig. 4).
Rice. Fig. 4. Scheme of the Wojciechowski continuous combustion of gas behind a triple configuration of shock waves circulating in the annular channel: 1 - fresh mixture; 2 - doubly compressed mixture behind a triple configuration of shock waves, detonation area
IN this case the stationary hydrodynamic process with gas combustion behind the shock wave differs from the detonation scheme of Chapman-Jouguet and Zel'dovich-Neumann. Such a process is quite stable, its duration is determined by the reserve of the fuel mixture and, in well-known experiments, is several tens of seconds.
Wojciechowski's detonation engine scheme served as a prototype numerous studies̆ rotational and spin detonation engines̆ initiated in the last 5 years. This scheme accounts for more than 85% of all studies. All of them have one organic drawback - the detonation zone occupies too little of the total combustion zone, usually no more than 15%. As a result, the specific performance of engines is worse than that of engines of traditional design.
On the causes of failures with the implementation of the Wojciechowski scheme
Most of the work on engines with continuous detonation is associated with the development of the Wojciechowski concept. Despite the more than 40-year history of research, the results actually remained at the level of 1964. The share of detonation combustion does not exceed 15% of the volume of the combustion chamber. The rest is slow combustion under conditions that are far from optimal.
One of the reasons for this state of affairs is the lack of a workable calculation methodology. Since the flow is three-dimensional, and the calculation takes into account only the laws of conservation of momentum on the shock wave in the direction perpendicular to the model detonation front, the results of calculating the inclination of shock waves to the flow of combustion products differ from those observed experimentally by more than 30%. The result is that, despite many years of research various systems fuel supply and experiments on changing the ratio of fuel components, all that has been done is to create models in which detonation combustion occurs and is maintained for 10-15 s. There is no talk of increasing efficiency, or of advantages over existing liquid-propellant and gas-turbine engines.
The analysis of the available RDE schemes carried out by the authors of the project showed that all the RDE schemes offered today are inoperative in principle. Detonation combustion occurs and is successfully maintained, but only to a limited extent. In the rest of the volume, we are dealing with the usual slow combustion, moreover, behind a non-optimal system of shock waves, which leads to significant losses full pressure. In addition, the pressure is also several times lower than necessary for ideal combustion conditions with a stoichiometric ratio of the fuel mixture components. As a result, the specific fuel consumption per unit of thrust is 30-40% higher than that of conventional engines.
But most main problem is the very principle of organization continuous detonation. As shown by studies of continuous circular detonation, carried out back in the 60s, the detonation combustion front is a complex shock wave structure consisting of at least two triple configurations (about triple configurations of shock waves. Such a structure with an attached detonation zone, like any thermodynamic system with feedback, left alone, tends to take a position corresponding to the minimum level of energy. As a result, the triple configurations and the area of detonation combustion are adjusted to each other so that the detonation front moves along the annular gap with the minimum possible volume of detonation combustion for this. This is directly opposite to the goal that engine designers set for detonation combustion.
For creating efficient engine RDE needs to solve the problem of creating an optimal triple configuration of shock waves and organizing a detonation combustion zone in it. Optimal shock-wave structures must be able to create in a variety of technical devices, for example, in optimal diffusers of supersonic air intakes. The main task is the maximum possible increase in the share of detonation combustion in the volume of the combustion chamber from today's unacceptable 15% to at least 85%. Existing engine designs based on the schemes of Nichols and Wojciechowski cannot provide this task.
Reviewers:Uskov V.N., Doctor of Technical Sciences, Professor of the Department of Hydroaeromechanics of St. Petersburg State University, Faculty of Mathematics and Mechanics, St. Petersburg;
Emelyanov V.N., Doctor of Technical Sciences, Professor, Head of the Department of Plasma Gas Dynamics and Heat Engineering, BSTU "VOENMEH" named after A.I. D.F. Ustinov, St. Petersburg.
The work was received by the editors on October 14, 2013.
Bibliographic link
Bulat P.V., Prodan N.V. REVIEW OF PROJECTS OF DETONATING ENGINES. ROTARY DETONATING ENGINES // Fundamental Research. - 2013. - No. 10-8. - S. 1672-1675;URL: http://fundamental-research.ru/ru/article/view?id=32642 (date of access: 03/04/2019). We bring to your attention the journals published by the publishing house "Academy of Natural History"
The Lyulka Experimental Design Bureau developed, manufactured and tested a prototype of a pulsating resonator detonation engine with a two-stage combustion of a kerosene-air mixture. According to ITAR-TASS, the average measured thrust of the engine was about one hundred kilograms, and the duration continuous work─ more than ten minutes. By the end of this year, the Design Bureau intends to manufacture and test a full-size pulsating detonation engine.
According to Alexander Tarasov, chief designer of the Lyulka Design Bureau, during the tests, the operating modes characteristic of a turbojet and ramjet engines. Measured values of specific thrust and specific consumption propellants proved to be 30-50 percent better than conventional jet engines. During the experiments, the new engine was switched on and off repeatedly, as well as traction control.
On the basis of the studies carried out, the data obtained during testing, as well as the circuit design analysis, the Lyulka Design Bureau intends to propose the development of a whole family of pulsed detonation aircraft engines. In particular, engines with a short service life for unmanned vehicles can be created. aircraft and missiles and aircraft engines with cruising supersonic flight.
In the future, based on new technologies, engines for rocket-space systems and combined power plants aircraft capable of flying in and out of the atmosphere.
According to the design bureau, the new engines will increase the aircraft's thrust-to-weight ratio by 1.5-2 times. In addition, when using such power plants, the flight range or the mass of aircraft weapons can increase by 30-50 percent. At the same time, the specific weight of the new engines will be 1.5-2 times less than that of conventional jet power plants.
The fact that in Russia work is underway to create a pulsating detonation engine was reported in March 2011. This was stated then by Ilya Fedorov, managing director of the Saturn research and production association, which includes the Lyulka Design Bureau. What type of detonation engine was in question, Fedorov did not specify.
Currently, three types of pulsating engines are known - valved, valveless and detonation. The principle of operation of these power plants is to periodically supply fuel and oxidizer to the combustion chamber, where the fuel mixture is ignited and the combustion products flow out of the nozzle with the formation jet thrust. The difference from conventional jet engines lies in the detonation combustion of the fuel mixture, in which the combustion front propagates faster speed sound.
Throbbing jet engine was invented at the end of the 19th century by the Swedish engineer Martin Wiberg. A pulsating engine is considered simple and cheap to manufacture, but due to the characteristics of fuel combustion, it is unreliable. First new type The engine was used in series during World War II on German V-1 cruise missiles. They were equipped with the Argus As-014 engine from Argus-Werken.
Currently, several major defense firms in the world are engaged in research in the field of high-efficiency pulsating jet engines. In particular, the work is being carried out by the French company SNECMA and American General Electric and Pratt & Whitney. In 2012, the US Naval Research Laboratory announced its intention to develop a spin detonation engine that would replace conventional gas turbine power plants on ships.
The US Navy Research Laboratory (NRL) intends to develop a rotary, or spin, detonation engine (Rotating Detonation Engine, RDE), which in the future will be able to replace conventional gas turbine power plants on ships. According to NRL, the new engines will allow the military to reduce fuel consumption while increasing the energy efficiency of power plants.
The US Navy currently operates 430 gas turbine engines (GTEs) on 129 ships. They consume two billion dollars worth of fuel every year. The NRL estimates that the RDE could save the military up to $400 million a year on fuel. RDE will be able to generate ten percent more power than conventional gas turbine engines. The RDE prototype has already been created, but when such engines will begin to enter the fleet is still unknown.
The RDE was based on the NRL developments obtained during the creation of a pulsating detonation engine (Pulse Detonation Engine, PDE). The operation of such power plants is based on the stable detonation combustion of the fuel mixture.
Spin detonation engines differ from pulsating ones in that the detonation combustion of the fuel mixture in them occurs continuously ─ the combustion front moves in the annular combustion chamber, in which the fuel mixture is constantly updated.
The publication "Military-Industrial Courier" reports great news from the field of breakthrough missile technologies. Detonation rocket engine 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 Deputy Prime Minister.
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 4 - 6 Machs (Max - 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 im. 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 is our conversation with the Deputy General Director - Chief Designer of NPO Energomash im. Academician V.P. Glushko" by 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 rockets 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 of a rocket engine. All this leads to a decrease in the cost of the 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 not quite further successful experiments they didn't make any progress.
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 named after A.I. 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.
