Detonation engine. In Russia, the detonation engine was tested by two tons. - has a higher efficiency
Why are simple ordinary people like terrible films? It turns out that it is an opportunity to survive your fears, to become more confident and even to release steam. And it really is so - you just need to choose an exciting horror film for yourself, which will make it necessary to go for heroes.
Silent Hill
History develops in the city of Silent Hill. Ordinary people would not want to even pass by him. But Rose Dasilva, Mom's little sheron, just forced to go there. Do not have another way out. She believes that it will only help his daughter and keeps her from a psychiatric hospital. The name of the town did not come from nowhere - Sheron constantly repeated it in a dream. And it seems that the cure is very close, but on the way to Silent Hill Mother and daughter get into a strange accident. After waking, Rose discovers that Sheron disappeared. Now a woman needs to find a daughter in the damned city, full of fears and horrors. The movie trailer is available for viewing.
Mirrors
Former Detective Ben Carson is experiencing not best times. After a random murder, his colleague is removed from work in the police department of New York. Further the departure of his wife and children, addiction to alcohol, and now Bin night watchdog of the burnt department store, who remained alone with his problems. Over time, the work therapy gives its fruits, but everything changes one night bypass. Mirrors begin to threaten Ben and his family. In their reflection there are strange and frightening images. To preserve life with your loved ones, the detective need to understand what mirrors want, but the problem is that Ben never faced mysticism.
Refuge
Kara Harding the death of her husband alone raises her daughter. The woman went on the footsteps of the Father and became a famous psychiatrist. She studies people with a split personality. Among them are those who claim that these personalities are much more. According to Kara, it is only the cover of serial killers, so all of her patients go to the death penalty. But one day, his father shows the daughter's case of Adam's Patient Patient, who is not amenable to any rational explanations. Kara continues to insist on his theory and even trying to cure Adam, but over time she opens up completely unexpected facts ...
Mike Enslin does not believe in the existence of the afterlife. Being a writer in the "Horror" genre, he writes another book about the supernatural. It is dedicated to Poltergeists living in hotels. In one of them Mike and decides to settle. The choice falls into the infamous number 1408 of the Dolphin hotels. According to the owners of the hotel and residents of the city, the evil that killing guests lives in the room. But neither this fact nor the warning of the senior manager scares the Mike. And in vain ... In the room, the writer will have to go through a real nightmare, it is possible to get out of which can be selected in one way ...
The material is prepared using an IVI online cinema.
Technology is in the development process!
The detonation engine is easier and cheaper in the manufacture, an order of magnitude more powerful and more economical than a conventional jet engine, compared to it has a higher efficiency.
Description:
The detonation engine (pulse, pulsating engine) is replaced by a conventional jet engine. To understand the essence of the detonation engine, it is necessary to disassemble the usual jet engine.
Normal jet engine arranged as follows.
In the combustion chamber, fuel and oxidizing agent occurs, the oxygen from the air performs. In this case, the pressure in the combustion chamber is constant. The combustion process sharply increases the temperature, creates a constant flame front and constant reactive craving, expire from the nozzle. The front of the usual flame is distributed in a gas environment at a speed of 60-100 m / s. Due to this and moves aircraft . However, modern jet engines have reached a certain limit of efficiency, power and other characteristics, the increase of which is almost impossible or extremely difficult.
In the detonation (pulse or pulsating) engine combustion occurs by detonation. Detonation is a combustion process, but which occurs hundreds of times faster than with the usual fuel burning. With detonation combustion, a detonation shock wave is formed, carrying with supersonic speeds. It is about 2500 m / s. The pressure as a result of detonation combustion increases rapidly, and the volume of the combustion chamber remains unchanged. Combustion products are pulled out with a huge speed through nozzle. The frequency of pulsations of the detonation wave reaches several thousand per second. In the detonation wave there is no stabilization of the front of the flame, on each ripple is updated fuel mixture And the wave starts again.
The pressure in the detonation engine is created due to the detonation itself, which eliminates the supply of the fuel mixture and the oxidant at high pressure. In a conventional jet engine to create a pressure of 200 atm., It is necessary to supply the fuel mixture under a pressure of 500 atm. While in the detonation motor - the fuel mixture pressure is 10 atm.
The detonation engine combustion chamber structurally has an annular shape with nozzles placed by its radius for fuel supply. The detonation wave runs around the circumference again and again, the fuel mixture is compressed and burns out, pushing the combustion products through the nozzle.
Benefits:
- The detonation engine is simpler in the manufacture. There is no need to use turbocharging units,
– The order is more powerful and more economical than the usual reactive engine,
- has a higher efficiency,
– cheaper in manufacturing,
- No need to create high pressure supply fuel mixture and oxidizing agent, high pressure is created due to the detonation itself,
– The detonation engine is superior to a conventional jet engine 10 times by power removed from the volume unit, which leads to a decrease in the design of the detonation engine,
- detonation combustion 100 times faster than the usual burning of fuel.
Note: © photo https://www.pexels.com, https://pixabay.com
Successful tests of so-called detonation rocket engines, which gave very interesting results. Experimental work in this direction will be continued.
On Energomashev engines, more ninety percent of carrier missiles in Russia takes off .. Photo: Olesya Kurpeeva
Detonation is an explosion. Is it possible to make it controlled? Is it possible to create hypersonic weapons on the basis of such engines? What rocket engines will deduct uninhabited and manned apparatuses in the near space? About this, our conversation with the deputy general director is the chief designer "NGO Energomash. Academician V.P. Glushko" Peter Levochkin.
Peter Sergeevich, what opportunities do new engines open?
Peter Levochkin: If we talk about the closest perspective, today we are working on engines for missiles such as "Angara A5V" and "Soyuz-5", as well as others who are in the pre-project stage and are unknown to the general public. In general, our engines are designed to leave the rocket from the surface of the celestial body. And she can be any - earthly, lunar, Martian. So, if moon or Martian programs are implemented, we will definitely take part in them.
What is the effectiveness of modern rocket engines and are there any ways to improve them?
Peter Levochkin:If we talk about the energy and thermodynamic parameters of the engines, it can be said that our, as well as the best foreign chemical rocket engines today reached a certain perfection. For example, fullness of fuel combustion reaches 98.5 percent. That is, almost all the chemical energy of fuel in the engine is converted to the thermal energy of the expiring jet of gas from the nozzle.
Improve engines in different directions. This is the use of more energy-intensive fuel components, the introduction of new circuit solutions, an increase in pressure in the combustion chamber. Another area is the use of new, including additive, technologies in order to reduce labor intensity and, as a result, reducing the value of the rocket engine. All this leads to a decrease in the cost of the output load.
However, with more detailed consideration it becomes clear that increasing the energy characteristics of the engines in the traditional way is ineffective.
Using a controlled fuel explosion can give rocket speed eight times higher than sound speed
Why?
Peter Levochkin:An increase in the pressure and fuel consumption in the combustion chamber will naturally increase the engine thrust. But it will require an increase in the wall thickness of the chamber and pumps. As a result, the complexity of the design and its mass increases, the energy gain is not so big. Sheepbank is not worth it.
That is, rocket engines have exhausted their resource of their development?
Peter Levochkin:Not certainly in that way. I am expressed by the technical language, they can be improved through an increase in the efficiency of intricate processes. There are cycles of thermodynamic transformation of chemical energy into the energy of the expiring jet, which are much more effective than the classical combustion of rocket fuel. This is a cycle of detonation combustion and a cycle of Humphrey close to it.
The effect of fuel detonation itself opened our compatriot - afterwards Academician Jacob Borisovich Zeldovich back in 1940. The implementation of this effect in practice promised very large prospects in rocket people. It is not surprising that the Germans in the same years have actively investigated the detonation process of burning. But not at all successful experiments They did not come to them.
Theoretical calculations have shown that detonation combustion by 25 percent more effective than an isobaric cycle, appropriately combining fuel at constant pressure, which is implemented in the chambers of modern liquid-rocket engines.
And what are the advantages of detonation burning compared to classic?
Peter 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 with dialing combustion, implemented in classical rocket engines with the same mass of burning fuel. And for us, engines, this means that with a significantly smaller dimensions of the detonation engine and with a small mass of the fuel, you can get the same craving as in huge modern liquid rocket engines.
It is no secret that the motors with detonation burning of fuel are developing abroad. What are our positions? We give up, go at their level or lead?
Peter Levochkin: Do not give up - that's for sure. But also to say that I can not lead. The topic is closed enough. One of the main technological secrets is how to ensure that the fuel and oxidizing agent of the rocket engine is not burned, but exploded, while not destroying the combustion chamber. That is, actually make a real explosion controlled and manageable. For reference: detonation is the burning of fuel at the front of the supersonic shock wave. There is a pulse 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 is known, with the participation of your specialists, experimental studies of detonation burning were carried out. What results were received?
Peter Levochkin: Work was performed on the creation of a model chamber of the liquid detonation rocket engine. Above the project under the patronage of the promising research fund, a large cooperation of leading scientific centers of Russia worked. Among them, the Institute of Hydrodynamics them. MA Lavrentiev, MAI, Celdysh Center, Central Institute of Aviation Motor Station. P.I. Baranova, Mechanics and Mathematics Faculty of Moscow State University. As a fuel, we suggested using kerosene, and oxidizing agent - gas oxygen. In the process of theoretical and experimental studies, the possibility of creating a detonation rocket engine on such components was confirmed. Based on the data obtained, we developed, manufactured and successfully tested the detonation model chamber with 2 tons and pressure in the combustion chamber of about 40 atm.
This task was solved for the first time not only in Russia, but also the world. Therefore, of course, the problems were. Firstly, associated with ensuring the sustainable detonation of oxygen with kerosene, secondly, with ensuring reliable cooling of the fire wall of the chamber without a vein cooling and a mass of other problems, the essence of which is understandable only to those skilled in the art.
Is it possible to use a detonation engine in hypersonic rockets?
Peter Levochkin:And you can, and you need. If only because the burning of fuel in it is supersonic. And in those engines that are now trying to create controlled hypersonic aircraft, burning subsonic. And it creates a lot of problems. After all, if the engine is in the engine at the engine, and the engine flies, let's say, with a speed of five masks (one max is equal to the speed of sound), it is necessary to brake the oncoming air flow to sound mode. Accordingly, all the energy of this braking goes into heat, which leads to additional overheating of the structure.
And in the detonation engine, the combustion process goes at a speed of at least two and a half times higher sound. And, accordingly, we can increase the speed of the aircraft for this magnitude. That is, we are not talking about five, but about eight mahas. This is actually achieving the speed of aircraft with hypersonic engines, in which the principle of detonation combustion will be used.
Peter Levochkin:This is a difficult question. We only opened the door to the detonation burning area. A very much unexplored remained behind the brackets of our study. Today, together with the RKK "Energy", we are trying to determine how can the engine as a whole with a detonation chamber looks like an overtaking blocks.
What motors do people fly to distant planets?
Peter Levochkin: In my opinion, for a long time we will fly on traditional EDD engaging in improving them. Although other types of rocket engines are certainly developing, for example, electrical panels (they are much more efficient to EDD - the specific impulse is 10 times higher). Alas, today's engines and removal means do not allow us to talk about the reality of mass interplanetary, and even more so intergalactic flights. There are still all at the level of fiction: photon engines, teleportation, levitation, gravitational waves. Although, on the other hand, just a hundred and small years ago, the writings of Jules were perceived as pure fiction. Perhaps a revolutionary breakthrough in the sphere where we work, it remains to wait at all long. Including in the field of practical creation of missiles using an explosion energy.
Dossier "RG"
"Energomash Scientific and Production Association" is founded by Valentin Petrovich Glushko in 1929. Now wears his name. Liquid rocket engines for I are developed and produced, in some cases II stages of carrier missiles. In NGOs have developed more than 60 different liquid jet engines. The first satellite was launched on Energomash engines, the first person was held in space, the first self-propelled apparatus "Lunohod-1" was launched. Today, on engines developed and manufactured in NGO "Energomash", more than ninety percent of carrier missiles in Russia takes off.
Infographics "RG" / Alexander Smirnov / Sergey Blischkin
In fact, instead of a constant frontal flame in the combustion zone, a detonation wave is formed, carrying with supersonic speeds. In such a wave of compression, the fuel and oxidizer are detonated, this process, in terms of thermodynamics increases Efficiency engine An order of magnitude, thanks to the compactness of the combustion zone.
Interestingly, in 1940, Soviet physicist Ya.B. Zeldovich proposed the idea of \u200b\u200ba detonation engine in the article "On the energy use of detonation combustion". Since then, many scientists have worked on a promising idea different countriesThe United States, then, Germany, then our compatriots were published.
In the summer, in August 2016, Russian scientists managed to create a full-size liquid jet engine for the first time in the world, operating on the principle of detonation combustion of fuel. Our country finally has established world priority in mastering the latest technology.
What is so good new engine? In the reactive motor, the energy is used, isolated when burning the mixture at a constant pressure and a constant flame front. A gas mixture of fuel and oxidant with combustion sharply increases the temperature and column of a flame that breaks out of the nozzle creates a reactive traction.
With detonation combustion, the reaction products do not have time to collapse, because this process is 100 times faster than deflating and pressure at the same time increases rapidly, and the volume remains unchanged. The allocation of such a large amount of energy can really destroy the car engine, so such a process is often associated with an explosion.
In fact, instead of a constant frontal flame in the combustion zone, a detonation wave is formed, carrying with supersonic speeds. In such a compression wave, the 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, thanks to the compactness of the combustion zone. Therefore, experts are so zealo and have begun to develop this idea. In the usual EDR, in fact, which is a large burner, the main thing is not the camera of combustion and nozzle, but the fuel pumping unit (TNA), which creates such pressure so that the fuel penetrates into the chamber. For example, in the Russian EDRD RD-170 for the energy carrier missiles, the pressure in the combustion chamber of 250 atm and the pump that the oxidizer in the combustion zone has to create a pressure of 600 atm.
In the detonation engine, the pressure is created by the detonation itself, representing a running compression wave in a fuel mixture, in which pressure without any TNA is already 20 times more and turbocharging units are superfluous. In order to be clear, the American "shuttle" pressure in the combustion chamber 200 atm, and the detonation engine in such conditions it is necessary only 10 atm for supplying a mixture - it is like a bicycle pump and Sayano-Shushenskaya HPP.
The engine based on detonation in this case is not only simpler and cheap to the whole order, but much more powerful and more economical than the usual EDD. On the path of implementation of the Detonation Engine project, the problem of concomposition with a wave of detonation. This phenomenon is not easy to explosive wave, which has the speed of sound, and the detonation, spreading at a speed of 2500 m / s, there is no stabilization of the flame front, the mixture and the wave is updated for each ripple again.
Previously, Russian and French engineers developed and built jet pulsating engines, but not on the principle of detonation, but on the basis of the ripple of ordinary burning. Characteristics of such PUVDs were low and when the engine engineers developed pumps, turbines and compressors, the age of jet engines and EDD, and pulsating remained on the side of progress. The bright heads of science tried to combine detonation combustion with PUVD, but the frequency of ripples of the usual burning front is no more than 250 per second, and the detonation front has a speed of up to 2500 m / s and the frequency of its ripples reaches several thousand per second. It seemed impossible to embody in practice such a speed of renewal of the mixture and at the same time initiate detonation.
In the SSRC, it was possible to build such a detonation pulsating engine and test it in the air, however, it worked only 10 seconds, but the priority remained behind the American designers. But already in the 60s of the last century, the Soviet scientist B.V. Wojjtzkhovsky and almost at the same time and the American from the university in Michigan J. Nicholas came the idea to begged in the combustion chamber by the wave of detonation.
Such a rotary engine consisted of a ring combustion chamber with nozzles placed on its radius for fuel supply. The detonation wave runs as a protein in the wheel in the circumference, the fuel mixture is compressed and burns out, pushing the combustion products through the nozzle. In the spin engine we obtain the frequency of rotation of the wave several thousand per second, its work is similar to the workflow in the FDMS, only more efficiently, due to the detonation of the fuel mixture.
In the USSR and the United States, and later in Russia, work is underway to create a rotary detonation engine with an unlucky wave, an understanding of the processes occurring inside, for which a whole science of physico-chemical kinetics was created. To calculate the conditions of the unsuccessful wave, we needed powerful computers that created only recently.
In Russia, many NII and KB are working on the project of such a spin engine, among which the engineering company of the Space Industry of NGO Energomash. For aid to develop such an engine, a fund of promising research came, because financing from the Ministry of Defense cannot be achieved - they only submit a guaranteed result.
Nevertheless, on the tests in Khimki at Energomash, the established continuous spin detonation regime was recorded - 8 thousand revolutions per second at the oxygen - kerosene mixture. In this case, detonation waves bated vibration waves, and heat coatings withstood high temperatures.
But it is not worth sharing, because this is only a demonstrator engine, which has worked very short time and the characteristics of it still says nothing. But the main thing is that the possibility of creating detonation burning is proved and a full-size spin engine is created in Russia, which will remain in the history of science forever.
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 is its engines creating reactive traction. 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: whether rocket Engine Instead of deflaring, use detonation and will the replacement of the combustion regime to improve the energy efficiency of the engine?
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 not organized 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%.
