Detonation engine. The detonation engine is the future of the Russian engine. Pulse and continuous modes

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At the end of January, reports of new successes of Russian science and technology appeared. From official sources it became known that one of the domestic projects of a promising jet engine of detonation type has already passed the test stage. This brings the moment of complete completion of all required works, based on the results of which cosmic or military rockets of Russian development will be able to obtain new power plants with increased characteristics. Moreover, new principles of engine operation can be used 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 Patriotic Press on the latest success of research organizations. Among the other, he touched the creation process jet enginesUsing new principles of work. A promising engine with detonation burning has already been brought to the test. According to the vice-premier, the application of new work principles power plant Allows you to get a significant increase in characteristics. In comparison with the constructs of traditional architecture, there is an increase in thrust of about 30%.

Modern rocket engines of different classes and types operated in various fields are used by the so-called. Isobaric cycle or deflagration burning. In their combustion chambers, constant pressure is maintained, in which slow fuel burning occurs. The engine on the deflagration principles does not need particularly durable units, but is limited in maximum indicators. Increasing the main characteristics, starting from a certain level, it turns out to be unreasonably complex.

An alternative to the engine with an isobaric cycle in the context of improving the characteristics - the system with the so-called. detonation burning. In this case, the fuel oxidation reaction occurs behind the shock wave, with a high speed moving along the combustion chamber. This makes special requirements for the engine design, but it gives obvious advantages. From the point of view of the efficiency of combustion of fuel, detonation burning is 25% better than the deflagration. Also differs from burning with a constant pressure of the increased power of heat dissipation from the unit of the surface of the reaction front. In theory, it is possible to increase this parameter by three or four orders. As a result, the speed of jet gases can be increased by 20-25 times.

Thus, the detonation engine, differing in an increased efficiency, is able to develop a large thrust with less fuel consumption. Its advantages over traditional designs are obvious, however, until recently, progress in this area left much to be desired. The principles of the detonation jet engine were formulated back in 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 the creation of a sufficiently strong design, as well as the complexity of the launch and subsequent maintenance of the shock wave when applying existing fuels.

One of the last domestic projects in the field of detonation rocket engines Started in 2014 and is being developed in NGO "Energomash" them. Academician V.P. Glush. According to the available data, the goal of the project with the "Iphret" cipher was to study the basic principles of new techniques, followed by the creation of a liquid rocket engine using kerosene and gas oxygen. The basis of the new engine called by the name of fiery demons from Arab Folklore, the principle of spin detonation burning was laid. Thus, in accordance with the main idea of \u200b\u200bthe project, the shock wave should continuously move in a circle inside the combustion chamber.

The head developer of the new project was NGO Energomash, and more precisely created on its base a special laboratory. In addition, several other research and design organizations were attracted to the work. The program has supported the promising research fund. All participants in the project "Iphret" were able to form the optimal look of a promising engine, as well as create a model combustion chamber with new principles of work.

To explore the prospects for the entire direction and new ideas a few years ago, the so-called was built. Model detonation combustion chamber corresponding to the project requirements. Such an experienced engine with an abbreviated package was supposed to be used as a fuel liquid kerosene. As an oxidant was offered gas oxygen. In August 2016, the test chamber began. It is important that for the first time in history, the project of this kind managed to bring to the stage of poster checks. Previously, domestic and foreign detonation rocket engines were developed, but not tested.

During the tests of the model sample, it was possible to obtain very interesting results showing the correctness of the approaches used. So, through the use of the right materials and technologies, it turned out the pressure inside the combustion chamber to 40 atmospheres. The thrust of the experienced product reached 2 tons.

Within the framework of the "Iphret" project, certain results were obtained, but the domestic detonation engine on liquid fuel is still far from full-fledged practical application. Before introducing such equipment to new projects, designers and scientists have to solve a number of most serious tasks. Only after this, the rocket-space industry or defense industry will be able to begin the implementation of the potential of new techniques in practice.

In mid-January, the Russian Gazeta published an interview with the chief designer NPO "Energomash" by Peter Levochkin, the theme of which was the current state of affairs and the prospects for detonation engines. The representative of the developer's enterprise recalled the main provisions of the project, and also touched upon the topic of success achieved. In addition, he spoke about the possible areas of use of "Iphritis" and similar designs.

For example, detonation engines can be used in hypersonic aircraft. P. Levochkin reminded that the engines are now proposed for use on this technique, use subsonic combustion. With the hypersonic velocity of the flight apparatus, the air entering the engine must be braked to the sound mode. However, braking energy should lead to additional thermal loads on the glider. In detonation engines, the fuel combustion rate reaches at least m \u003d 2.5. Due to this, it becomes possible to increase the speed of the flight machine. A similar machine with a detonation type engine will be able to accelerate up to speeds, eight times higher than the speed of the sound.

However, the real perspectives of the detonation rocket engines are not too large. According to P. Levochka, we "only opened the door to the detonation burning area." Scientists and designers will have to study many questions, and only after that it will be possible to create structures with practical potential. Because of this space industry, the liquid engines of the traditional design will have long to be used, which, however, does not cancel the possibilities of their further improvement.

Interesting is the fact that the detonation principle of combustion finds the use of not only in the sphere of rocket engines. There is already a domestic project of the aviation system with a detonation combustion chamber operating on a pulse principle. An experienced sample of this kind was brought to the test, and in the future it can give a new direction. New detonation combustion engines can be used in a variety of spheres and partially replace gas turbine or turbojet engines of traditional designs.

The domestic project of the detonation aviation engine is developed in the OKB. A.M. Cradle. Information about this project was first presented at last year's International Military Technical Forum "Army 2017". At the booth of the company-developer, there were materials on various enginessuch as serial and under development. Among the latter was a promising detonation sample.

The essence of the new proposal is to apply a non-standard combustion chamber capable of carrying out the impulse detonation combustion of fuel in the 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 some interest.

However, the main advantages of the new power plant are associated with elevated characteristics. Bent tests of experienced products showed that they are about 30% superior to traditional gas turbine engines According to specific indicators. By the time of the first public demonstration of materials on the engine of the OKB. A.M. Cradles could get and high enough performance features. An experienced engine of a new type was able to work for 10 minutes without a break. The total operation of this product on the stand at that time exceeded 100 hours.

Representatives of the developer's enterprise pointed out that now you can create a new detonation engine with a 2-2.5 taway tape, 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. Resonator devices responsible for the correct fuel combustion course. An important advantage of the new project is the principal possible installation of such devices anywhere in the glider.

Specialists of the OKB. A.M. The crackers work on aircraft engines with impulse detonation burning of more than three decades, but while the project does not come out of the research stage and does not have real prospects. The main reason is the lack of order and the necessary funding. If the project gets the necessary support, then in the foreseeable future, an engine sample suitable for use on various techniques can be created.

To date, Russian scientists and designers have managed to show very remarkable results in the field of jet engines using new principles of work. There are several projects suitable for use in rocket and space and hypersonic areas. In addition, new engines can be applied in the "traditional" aviation. Some projects are still in early stages and are not yet ready for checks and other work, while in other directions the most remarkable results were already obtained.

Exploring the subject of jet engines with detonation burning, Russian experts were able to create a stand model sample combustion chamber with the desired characteristics. The experienced product "Iphret" has already passed the test, during which a large number of diverse information was collected. Using the obtained data, the development of the direction will continue.

The development of the new direction and the translation of ideas in almost applicable form will take a lot of time, and for this reason, in the foreseeable future, space and army missiles in the foreseeable future will be equipped with only traditional liquid engines. Nevertheless, the work has already come out of a purely theoretical stage, and now each test launch of an experimental engine brings the moment of construction of full missile with new power plants.

Among the other, he touched upon the process of creating jet engines using new principles of work. A promising engine with detonation burning has already been brought to the test. According to the Deputy Prime Minister, the application of new principles of operation of the power plant allows you to obtain a significant increase in characteristics. In comparison with the constructs of traditional architecture, there is an increase in thrust of about 30%.

Scheme of detonation rocket engine

One of the last domestic projects in the field of detonation rocket engines started in 2014 and is developed in NGO "Energomash". Academician V.P. Glush. According to the available data, the goal of the project with the "Iphret" cipher was to study the basic principles of new techniques, followed by the creation of a liquid rocket engine using kerosene and gas oxygen. The basis of the new engine called by the name of fiery demons from Arab Folklore, the principle of spin detonation burning was laid. Thus, in accordance with the main idea of \u200b\u200bthe project, the shock wave should continuously move in a circle inside the combustion chamber.

Model camera on a test bench

The domestic project of the detonation aviation engine is developed in the OKB. A.M. Cradle. Information about this project was first presented at last year's International Military Technical Forum "Army 2017". At the booth of the developer's company, materials were attended by various engines, both serial and under development. Among the latter was a promising detonation sample.

First launch of an experienced product "Iphret"

However, the main advantages of the new power plant are associated with elevated characteristics. Bench tests of experienced products have shown that they are about 30% superior to traditional gas turbine engines according to specific indicators. By the time of the first public demonstration of materials on the engine of the OKB. A.M. The cradles could get and sufficiently high performance. An experienced engine of a new type was able to work for 10 minutes without a break. The total operation of this product on the stand at that time exceeded 100 hours.

The development of the new direction and the translation of ideas in the almost applicable form will take a lot of time, and for this reason, in the foreseeable future, space and army missiles in the foreseeable future will be equipped with only traditional liquid engines. Nevertheless, the work has already come out of a purely theoretical stage, and now each test launch of an experimental engine brings the moment of construction of full missile with new power plants.

A new physical idea is the use of detonation burning instead of the usual, declaration - allows you to radically improve the characteristics of the reactive engine.

Speaking about space programs, we first think about powerful rockets that are withdrawn by space ships in orbit. The heart of the carrier rocket - its engines creating reactive craving. The rocket engine is the most complicated energy-forming device, in many respects resembling a living organism with its character and behavior manners, which is created by generations of scientists and engineers. Therefore, it is practically impossible to change something in the working machine: the rackets say: "Do not hinder the car to work ..." Such conservatism, although it is repeatedly justified by the practice of space starters, still slows down rocket-space engine - one of the most high-tech areas of human activity. The need for change has been abandoned for a long time: to solve a number of tasks, more energy-efficient engines are needed than those that are operated today and which by their perfection reached the limit.

We need new ideas, new physical principles. Below it will be discussed precisely about such an idea and its embodiment in the demonstration sample of a new type rocket engine.

Delable and detonation

In most existing rocket engines, the chemical energy of fuel is converted to heat and mechanical work Due to the slow (subsonic) combustion - deflagration - with almost constant pressure: P \u003d Const.. However, besides the deflagration, another combustion regime is known - detonation. During the detonation, the chemical fuel oxidation reaction flows in self-ignition mode at high temperatures and pressure values \u200b\u200bbehind a strong shock wave running with high supersonic speed. If, with the delagration of hydrocarbon fuel, the heat generation power from the unit of the surface of the reaction front is ~ 1 MW / m2, then the heat generation power in the detonation front is three to four orders of magnitude higher and can reach 10,000 MW / m2 (higher radiation power from the surface of the Sun!). In addition, unlike the products of slow burning, detonation products have a huge kinetic energy: the speed of detonation products at ~ 20-25 times higher than the speed of slow burning products. Questions arise: is it possible to use detonation instead of deflaration in the rocket engine and is it possible to replace the burning mode to improving the engine energy efficiency?

We give a simple example, which illustrates the advantages of detonation combustion in the rocket engine over deflagration. Consider three identical combustion chambers (COP) in the form of a pipe with one closed and another open end, which are filled with the same combustible mixture under the same conditions and are supplied with a closed end vertically on the tesimary scales (Fig. 1). The ignition energy will be considered negligible in comparison with the chemical energy of fuel in the pipe.

Fig. 1. Energy efficiency of the detonation engine

Suppose in the first pipe, the combustible mixture is ignited by one source, for example, automotive candlelocated near the closed end. After the ignition up the pipe will run the slow flame, the visible speed of which usually does not exceed 10 m / c, that is, much less sound speed (about 340 m / s). This means that the pressure in the pipe P. will differ very little from atmospheric PAAnd the testimony of weights will practically do not change. In other words, such (deflagration) combustion of the mixture actually does not lead to the appearance of overpressure at the closed end of the pipe, and, therefore, the additional force acting on the scales. In such cases, it is said that the useful work of the cycle with P.=PA=const.it is zero and, therefore, zero the thermodynamic efficiency (efficiency). That is why in existing power plants, the combustion is organized not at atmospheric, but at elevated pressure P."PAobtained using turbochasions. In modern rocket engines, the average pressure in the COP reaches 200-300 atm.

We will try to change the situation by setting in the second pipe a plurality of ignition sources, which simultaneously ignite a combustible mixture throughout the volume. In this case, the pressure in the pipe P. It will increase quickly, as a rule, in seven or ten times, and the testimony of weights will change: on the closed end of the pipe for some time - the time of the expiration of combustion products into the atmosphere - there will be a fairly much force that is able to make a lot of work. What has changed? The organization of the combustion process in COP has changed: instead of combustion at constant pressure P.=const. We organized burning at a constant volume V.=const..

Now let us recall the possibility of organizing the detonation combustion of our mixture and in the third pipe instead of a variety of distributed weak ignition sources install, as in the first pipe, one source of ignition from a closed end of the pipe, but not weak, but a strong one that will lead to a flame and detonation wave. Arriving, the detonation wave will run up the pipe with high supersonic speed (about 2000 m / s), so that the entire mixture in the pipe burns very quickly, and the pressure on average will increase both at a constant volume - seven or ten times. With more detailed consideration it turns out that the work performed in the cycle with detonation burning will be even higher than in the cycle V. = const..

Thus, with other things being equal, the detonation combustion of the combustible mixture in the COP allows you to get the maximum useful work compared with the deflagration burning when P.=const. and V.=const., that is, allows you to get the maximum thermodynamic efficiency . If instead of the existing rocket engines with delarlation burning, use motors with detonation burning, then such engines could give extremely large benefits. This result was first received by our great compatriot Academician Yakov Borisovich Zeldovich back in 1940, but still did not find practical application. The main reason for this is the complexity of the organization of managed detonation combustion of regular rocket fuels.

The heat generation capacity in the detonation front is 3-4 orders of order higher than in the front of the usual delaction combustion and can exceed the radiation power from the sun surface. The speed of detonation products is 20-25 times higher than the speed of slow burning products.

Pulse and continuous modes

To date, many schemes for the organization of managed detonation combustion are proposed, including schemes with pulse-detonation and continuously detonation workflow. The pulse-detonation workflow is based on the cyclic filling of the COP combustion mixture, followed by ignition, the distribution of detonation and the expiration of products into the surrounding space (as in the third pipe in the example above). The continuous-detonation workflow is based on the continuous supply of a combustible mixture in the COP and its continuous combustion in one or several detonation waves, continuously circulating in the tangential direction across the stream.

The concept of the COP with continuous detonation was proposed in 1959 by Academician Bogdan Vyacheslavovich Wentschov and for a long time studied at the Institute of Hydrodynamics SB RAS. The simplest continuous-detonation COP is an annular channel formed by the walls of two coaxial cylinders (Fig. 2). If on the bottom of the annular channel to place the mixing head, and the other end of the channel to equip the reactive nozzle, then the flowing ring jet engine will turn out. Detonation combustion in such a COP can be organized, burning the combustible mixture supplied through the mixing head, in the detonation wave continuously circulating over the bottom. At the same time, a combustible mixture will be burned in the detonation wave, re-entered in the COP during one turnover of the wave around the circle of the ring canal. Other advantages of such COP include simplicity of design, single ignition, quasi-stationary expiration of detonation products, high frequency of cycles (kiloherts), low longitudinal size, low emission level harmful substances, Low noise and vibrations.

The specified specific impulse in the detonation rocket engine is achieved with a significantly less pressure than in the traditional liquid rocket engine. This will allow in the future to drastically change the mass boiler characteristics of rocket engines

Fig. 2. Scheme of the detonation rocket engine

Demonstration sample

In the framework of the project of the Ministry of Education, a demonstration sample of a continuous-detonation rocket engine (DRD) with a COP with a diameter of 100 mm and a ring channel width of 5 mm, which is tested when working on hydrogen fuel pairs - oxygen, liquefied natural gas - oxygen and propane-butane -oxygen. DRD fire tests were carried out on a specially designed test bench. The duration of each fire test is not more than 2 s. During this time, with the help of special diagnostic equipment, tens of thousands of rotor of detonation waves were registered in the COP ring channel. When working DRD on fuel pare. Hydrogen - oxygen for the first time in the world experimentally proven that the thermodynamic cycle with detonation combustion (Zeldovich cycle) is 7-8% more efficient than the thermodynamic cycle with conventional burning, with other things being equal.

The project created a unique, which does not have world analogues computational technology intended for full-scale modeling of the workflow in DRD. This technology actually allows you to design a new type engines. When comparing the results of calculations with measurements, it turned out that the calculation precisely predicts the number of detonation waves circulating in the tangential direction in the annular CS DRD of a given design (four, three or one wave, Fig. 3). The calculation with an acceptable accuracy predicts the operating frequency of the process, that is, gives the values \u200b\u200bof the detonation speed, close to the measured, and the craving actually developed DRD. In addition, the calculation correctly predicts the trends in the change in the parameters of the workflow while increasing the flow rate of the combustible mixture in the DRD of a given design - as in the experiment, the number of detonation waves, the rate of rotation of detonation and the thrust increases.

Fig. 3. Quasistationary calculated fields of pressure (A, B) and temperature (B) under conditions of three experiments (from left to right). As in experiments, modes with four, three and one detonation waves were obtained in the calculations.

DRD against EDD

The main indicator of the energy efficiency of the rocket engine is a specific pulse of thrust equal to the ratio of the thrust developed by the engine, to the weight secondary flow rate of the combustible mixture. The specific impulse is measured in seconds (C). The dependence of the specific pulse of the DRD thrust from the average pressure in the COP obtained during the firing test of the engine of a new type is such that the specific impulse increases with an increase in the average pressure in the COP. The main target indicator of the project is the specific impulse of 40 s in conditions at sea level - achieved in fire tests at an average pressure in the CS, equal to 32 atm. The measured traction DRD at the same time exceeded 3 kN.

When comparing the specific characteristics of DRD with specific characteristics in traditional liquid rocket engines (EDD), it turns out that the specified specific impulse in the DRD is achieved with a much smaller average pressure than in the EDD. Thus, in the DRD, the specific impulse in 260 ° C is achieved at a pressure in the COP of only 24 atm, while the specific impulse 263.3 C in a known domestic engine of RD-107A is achieved at a pressure of 61.2 atm, which is 2.5 times higher. . It should be noted that the RD-107A engine operates on the fuel pair of kerosene - oxygen and is used in the first stage of the Soyuz-FG carrier rocket. Such a significant decrease in the average pressure in DRD will allow in the future to drastically change the mass boar characteristics of rocket engines and reduce the requirements for turbocharging units.

Here is a new idea, and new physical principles.

One of the results of the project is a developed technical task for conducting developmental work (OCD) to create a prototype DRD. The main problem is planned to be solved within the framework of the OCD - to ensure the continuous operation of the DRD for a long time (dozens of minutes). This requires to develop an effective cooling system of the engine walls.

Due to its breakthrough nature, the task of creating a practical DRD undoubtedly should be one of the priorities of the domestic space engine industry.

Sergey Frolov, Doctor of Physical and Mathematical Sciences, Institute of Chemical Physics. N.N. Semenova RAS, Professor Niauu-Mafi

Gas instead kerosene

In 2014-2016, the Ministry of Education and Science of the Russian Federation supported the project "Development of technologies for using liquefied natural gas (methane, propane, butane) as fuel for rocket and space technology of a new generation and the creation of a stand demonstration sample of the rocket engine." The project provides for the creation of a demonstration sample of a continuous-detonation rocket engine (DRD) operating on the fuel pair "Liquefied natural gas (LNG) - oxygen". The project is the center of the impulse-detonation combustion of the Institute of Chemical Physics of the Russian Academy of Sciences. Industrial partner of the project - Turaevskaya Machine-Building Design Bureau "Union". In the application for a draft, the feasibility of use in the liquid rocket engine (EDD) of continuous-detonation combustion was due to a higher thermodynamic efficiency compared with a traditional cycle using slow combustion, and the expediency of using LNG was explained by a number of advantages compared to kerosene: an increased specific pulse of traction, Availability and low cost, significantly smaller plantation during combustion and higher environmental characteristics. Theoretically, the replacement of kerosene on LNG in the traditional EDR is thrown by an increase in the specific impulse by 3-4%, and the transition from traditional EDD to DRD is 13-15%.

In the last days of January, Deputy Prime Minister Dmitry Rogozin told the Patriotic Press on the latest success of research organizations. Among the other, he touched upon the process of creating jet engines using new principles of operation. A promising engine with detonation burning has already been brought to the test. According to the Deputy Prime Minister, the application of new principles of operation of the power plant allows you to obtain a significant increase in characteristics. In comparison with the constructs of traditional architecture, there is an increase in thrust of about 30%.

Scheme of detonation rocket engine

To explore the prospects for the entire direction and new ideas a few years ago, the so-called was built. Model detonation combustion chamber corresponding to the project requirements. Such an experienced engine with an abbreviated package was supposed to be used as a fuel liquid kerosene. As an oxidant was offered gas oxygen. In August 2016, the test chamber began. It is important that for the first time in the project of this kind, it was possible to bring to the stage of poster checks. Previously, domestic and foreign detonation rocket engines were developed, but not tested.

Model camera on a test bench

The domestic project of the detonation aviation engine is developed in the OKB. A.M. Cradle. Information about this project was first presented at last year's International Military Technical Forum "Army 2017". At the booth of the developer's company, materials were attended by various engines, both serial and under development. Among the latter was a promising detonation sample.

First launch of an experienced product "Iphret"

According to the materials of sites:
http://engine.space/
http://fpi.gov.ru/
https://rg.ru/
https://utro.ru/
http://tass.ru/
http://svpressa.ru/

Fig. 1. Energy efficiency of the detonation engine

Fig. 2. Scheme of the detonation rocket engine

Fig. 3. Quasistationary calculated fields of pressure (A, B) and temperature (B) under conditions of three experiments (from left to right). As in experiments, modes with four, three and one detonation waves were obtained in the calculations.

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