Calculation of PAUD. Fundamental studies. Other pulsating VD

In Russia, tested a pulsating detonation engine

The Liaulka's experimental design bureau has developed and experienced an experimental sample of a pulsating resonator detonation engine with a two-stage kerosene-grain mixture. According to ITAR-TASS, the average measured engine traction was about a hundred kilograms, and the duration of continuous operation ─ more than ten minutes. Until the end of this year, the OKB intends to make and test a full-size pulsating detonation engine.

According to the chief designer of the OKB named after Lulleka Alexander Tarasova, in the course of the tests were simulated modes of workcharacteristic of turbojet and directional engines. The measured values \u200b\u200bof the specific thrust and the specific fuel consumption were 30-50 percent better than that of ordinary air-jet engines. During the experiments, it was repeatedly turned on and off the new engine, as well as control of thrust.

Based on the studies obtained when testing data, as well as the scheme-design analysis of the Audley OKB, intends to offer the development of a whole family of pulsating detonation aircraft engines. In particular, engines with a short resource of work can be created for unmanned aircraft and rockets and aircraft engines with a cruising supersonic flight mode.

In the future, on the basis of new technologies, engines can be created for rocket and space systems and combined power plants Airplanes capable of flying in the atmosphere and beyond.

According to the design bureau, new engines will increase the plot of aircraft by 1.5-2 times. In addition, when using such power plants, the flight distance or mass of aviation lesions may increase by 30-50 percent. In this case, the share of new engines will be 1.5-2 times less than the same indicator of conventional reactive power plants.

The fact that in Russia work is underway to create a pulsating detonation engine, reported in March 2011. This was then stated by Ilya Fedorov, managing director of the Saturn Scientific and Production Association, which includes chalki OKB. About which type of detonation engine was speech, Fedorov did not specify.

Currently, three types of pulsating engines ─ valve, bauble and detonation are known. The principle of operation of these power plants lies in the periodic supply to the combustion chamber of fuel and the oxidizing agent, where the fuel mixture is ignited and the exhaust of combustion products from the nozzle with formation reactive traction. The difference from ordinary jet engines is the detonation burning of the fuel mixture, in which the burning front spreads faster speed Sound.

Throbbing air jet engine It was invented at the end of the XIX century by the Swedish engineer Martin Vieberg. The pulsating engine is considered simple and cheap in the manufacture, however, due to the peculiarities of the fuel combustion ─ low-tech. For the first time, the new type of engine was used serially during World War II on German Winged Rockets FAu-1. ARGUS-WERKEN company ARGUS AS-014 was installed on them.

Currently, several large defense firms of the world are engaged in research in the field of creating highly efficient pulsating jet engines. In particular, the works are conducted by the French company Snecma and American General Electric and Pratt & Whitney. In 2012, the US Navy Research Laboratory announced its intention to develop a spin detonation engine, which will have to replace ordinary gas turbine power plants on the ships.

Spin detonation engines They differ from pulsating the fact that the detonation burning of the fuel mixture in them is continuously ─ the combustion front moves in the ring combustion chamber in which the fuel mixture is constantly updated.

The PAUD scheme is presented in Fig.3.16.

Fig.3.16.Shem pulsating air-reactive engine:

diffuser, 2-valve device; 3-nozzles; 4 - Camera combustion; 5 - nozzle; 6- exhaust pipe.

The fuel is injected through the nozzles 3, forming the fuel mixture with air compressed in the diffuser 1.

The ignition of the fuel mixture is performed in the combustion chamber 4, from the electrical candle. The combustion of the fuel mixture is injected in certain quantities, lasts hundredths of a second. As soon as the pressure in the combustion chamber becomes more air pressure in front of the valve device, the placed valves are closed. With a sufficiently large volume of nozzle 5 and exhaust pipe 6, established specifically to increase the volume, a sub-center of gases in the combustion chamber is created. During the combustion of fuel, the change in the amount of gases in the amount behind the combustion chamber is negligible, therefore it is believed that the burning goes at a constant volume.

After combustion of the fuel portion, the pressure in the combustion chamber decreases so that the valves 2 open and admit a new portion of air from the diffuser.

Figure 3.17. Presents the perfect thermodynamic cycle of pulsating VD.

P
cycle roces:

1-2 - air compression in the diffuser;

2-3 - isochhore heat supply in the combustion chamber;

3-4 - adiabatic expansion of gases in the nozzle;

4-1 - the isobaric cooling of combustion products in the atmosphere with heat removal.

Fig.3.17. Cycle PUVD.

As follows from Fig. 3.17, the Pavdi cycle does not differ from the cycle of GTU with isochorous heat supply. Then, by analogy with (3.8.) You can immediately write down the formula for the thermal efficiency of PUVD

(3.20.)

The degree of additional increase in pressure in the combustion chamber;

- The degree of increase in pressure in the diffuser.

Thus, the thermal efficiency in the pulsating BPD is greater than that of PVRs due to the greater average integral temperature of the thermal vehicle.

The complication of the design of Pavds led to an increase in its mass compared to PVRS.

3.5.3. Compressor turbojet engines (TRD)

These engines got the greatest spread in aviation. Two-stage air compression (in the diffuser and in the compressor) and two-stage expansion of the combustion of the fuel mixture (in the gas turbine and in the nozzle) occurs in the TRP.

The TRD schematic diagram is presented in Figure 3.18.

Fig.3.18. Schematic scheme The TRD and the nature of the change in the working fluid parameters in the gas-air path:

1-diffuser; 2-axis compressor; 3-combustion chamber; 4- gas turbine; 5- nozzle.

The pressure of the incident air flow is first rises in the diffuser 1, and then in the compressor 2. The compressor drive is carried out from the gas turbine 4. The fuel is supplied to the combustion chamber 3, where with air forms fuel mixture and burns at constant pressure. Combustion products first expand on gas turbine blades 4, and then in a nozzle. The expiration of gases from the nozzle with a greater speed creates the force of the thrust moving the aircraft.

The perfect thermodynamic Cycle of the TRD is similar to the PVR Cycle, but is complemented by processes in the compressor and turbine (Fig.3.19).

Fig.3.19. The perfect Cycle of TRD inP.- V. diagram

Cycle processes:

1-2 - adiabatic air compression in the diffuser;

2-3 - adiabatic air compression in the compressor;

3-4 - the isobaric rise of heat from the combustion of the fuel mixture in the combustion chamber;

4-5 - adiabatic expansion of combustion products on turbine blades;

5-6 - adiabatic expansion of combustion products in the nozzle;

6-1 - cooling of combustion products in the atmosphere at a constant pressure with recycling of heat.

Thermal efficiency is determined by Formula (3.19):

(3.21.)

- the resulting degree of increase in air pressure in the diffuser and compressor.

Due to the higher than that of the PVRS, the CDR compression degree has a higher thermal efficiency. Without any start-up accelerators, the TRD develops the necessary thrust for the start.

Pulsing Air Jet Engine - option of the air-reactive engine. The PUVD is used to the combustion chamber with entrance valves and a long cylindrical outlet nozzle. Fuel and air are served periodically.

The work cycle of Pavdards consists of the following phases:

Valves open and air and fuel enters the combustion chamber, the air-fuel mixture is formed.
The mixture is mounted using the spark of the spark plug. The resulting overpressure closes the valve.
Hot combustion products overlook the nozzle creating reactive traction and technical vacuum in the combustion chamber.

History

The first patents on the pulsating air-jet engine (PAUD) were obtained (independently from each other) in the 60s of the XIX century Charch de Lumury (France) and Nikolai Afanasyevich Teloshovov (Russia). German designers, even on the eve of World War II, conducted a wide search for alternative to piston aviation engines, did not pay attention and this invention, the remaining unclaimed for a long time. The most famous aircraft (and the only serial) C Pavda Argus AS-014 produced by Argus-Werken was the German FAU-1 projectile aircraft. The chief designer Fow-1 Robert Lusser chose PUVD for him not for the sake of efficiency (piston aircraft engines of that era possessed best characteristics), and mainly due to the simplicity of the design and, as a result, small labor costs for the manufacture, which was justified when mass production Disposable shells, serially issued for an incomplete year (from June 1944 to March 1945) in the amount of over 10,000 units.

After the war, research in the field of pulsating air-jet engines continued in France (SNECMA) and in the United States (Pratt & Whitney, General Electric), the results of these developments were interested in the United States and the USSR. A number of experimental and experimental samples were developed. Initially, the main problem of air-surface missiles was in the imperfection of an inertial guidance system, the accuracy of which was considered good if the rocket from a distance of 150 kilometers fell into a square with the sides of 3 kilometers. This led to the fact that with a warhead on the basis of a conventional explosive, these rockets had low efficiency, and nuclear charges at the same time had an even majority (several tons). The pulsating air-jet engine has a large specific impulse compared to rocket engines, but is inferior to turbojet engines in this indicator. An essential limitation is that this engine requires overclocking to the operating rate of 100 m / s and its use is limited by the speed of about 250 m / s. When compact nuclear charges appeared, the design of more efficient turbojet engines has already been worked out. Therefore, pulsating air-jet engines were not widespread.

Structurally, PUVD is a cylindrical combustion chamber with a long cylindrical nozzle of a smaller diameter. The front of the chamber is connected to the input diffuser through which the air enters the chamber.

Between the diffuser and the combustion chamber, an air valve is installed under the influence of the pressure difference in the chamber and at the diffuser output: when the pressure in the diffuser exceeds the pressure in the chamber the valve opens and passes the air into the chamber; With the reverse pressure ratio, it closes.

The diagram of the pulsating air-reactive motor (PUVDD): 1 - air; 2 - fuel; 3 - valve grille; Behind it - the combustion chamber; 4 - Output (reactive) nozzle.

The valve may have a different design: in the Argus AS-014 engine of the FA-1 missiles, it had a form and actually acted like window shutters and consisted of stalled flexible rectangular plates from spring steel; In small engines, it looks like a plate in the form of a flower with radially located valve plates in the form of several thin, elastic metal petals, pressed to the base of the valve in a closed position and rejuvenated from the base under the action of pressure in the diffuser in excess of pressure in the chamber. The first design is much more perfect - it has minimal resistance to the air flow, but much more difficult in production.

Flexible rectangular valve plates

In front of the chamber there are one or more fuel injectors, which injected fuel into the chamber while the pressure of the boost in fuel tank exceeds the pressure in the chamber; Upon pressure in the pressure pressure chamber, the reverse valve in the fuel tract overlaps the fuel supply. Primitive low-power structures are often working without fuel injection, like a piston carburetor engine. To start the engine in this case, usually use external source Compressed air.

To initiate the combustion process in the chamber, the ignition candle is installed, which creates a high-frequency series of electrical discharges, and the fuel mixture is flammable as soon as the concentration of fuel in it reaches some sufficient to fire, level. When the hematic of the combustion chamber is sufficiently warming up (usually, in a few seconds after the start of work big Engine, or through the fraction of a second - small; Without cooling with air flow, the steel walls of the combustion chamber quickly heat up hot), electrode becomes unnecessary: \u200b\u200bthe fuel mixture flames from the hot walls of the chamber.

When working, PUVD issues a very characteristic crack or buzzing sound, due to ripples in his work.

Pavrd work scheme

The cycle of the PUVD is illustrated in the picture on the right:

1. The air valve is open, the air enters the combustion chamber, the nozzle injects fuel, and the fuel mixture is formed in the chamber.
2. The fuel mixture is flammified and combines, the pressure in the combustion chamber increases sharply and closes the air valve and the check valve in the fuel tract. Combustion products, expanding, expire from the nozzle, creating a reactive traction.
3. The pressure in the chamber is equal with atmospheric, under the pressure of the air in the diffuser, the air valve opens and the air begins to enter the chamber, fuel valve Also opens, the engine proceeds to phase 1.

The seeming similarity of PAUD and PVRS (perhaps due to the similarities of the abbreviation names) - erroneously. In fact, PUVD has deep, fundamental differences from PVRD or TRD.

Firstly, the presence of an air valve in the PUDRD, the apparent appointment of which is to prevent the inverse movement of the working fluid forward along the movement of the device (which will be reduced to no reactive traction). In PVRS (as in the TRD), this valve is not needed, since the inverse movement of the working fluid in the engine path prevents the "barrier" of the pressure at the inlet in the combustion chamber, created during the compression of the working fluid. In Pavd, the initial compression is too small, and the increase in pressure increase in the combustion chamber is achieved due to the heating of the working fluorescence (when combusting combustible) in a constant volume, bounded by the chamber walls, valve, and the inertia of the gas column in the long motor nozzle. Therefore, Pavdards from the point of view of thermodynamics of thermal engines belongs to another category, rather than PVRD or TRD - its work is described by the Humphrey Cycle (Humphrey), while the work of PVRC and TRD is described by Brighton's cycle.

Secondly, the pulsating, intermittent nature of the work of Pavdards, also contributes significant differences in the mechanism of its functioning, in comparison with the BWR of continuous action. To explain the work of Pavd, it is not enough to consider only gas-dynamic and thermodynamic processes occurring in it. The engine operates in self-oscillation mode, which synchronize the operation of all its elements by time. The frequency of these auto-oscillations affect the inertial characteristics of all parts of the PAUD, including the inertia of the gas column in the long nozzle engine, and the distribution time on it acoustic wave. An increase in the nozzle length leads to a decrease in the frequency of ripples and vice versa. At a certain length of the nozzle, a resonant frequency is achieved, in which autoballs become stable, and the amplitude of oscillations of each element is maximum. When developing the engine, this length is selected experimentally during testing and finishing.

Sometimes it is said that the functioning of the PUVD at zero velocity of the device is impossible - this is an erroneous representation, in any case, it cannot be distributed to all engines of this type. Most EAIs (unlike PVRS) can work, "standing still" (without a raid air flow), although the thrust developing in this mode is minimal (and usually insufficient for the start of the apparatus driven by him without any assistance - therefore, For example, V-1 launched from the steam catapult, while Pavda began to work steadily before starting).

Engine functioning in this case is explained as follows. When the pressure in the chamber after the next pulse decreases to atmospheric, the gas movement in the inertia's nozzle continues, and this leads to a decrease in pressure in the chamber to the level below atmospheric. When an air valve is opened under the influence of atmospheric pressure (for which it also takes some time), a sufficient vacuum has already been created in the chamber so that the engine can "breathe fresh air" in the amount required to continue the next cycle. Rocket engines in addition to traction are characterized by a specific impulse, which is an indicator of the degree of perfection or engine quality. This indicator is also a measure of engine efficiency. In the diagram below, the top values \u200b\u200bof this indicator are presented in graph form. different types Jet engines, depending on the flight speed, expressed in the form of a Mach number, which allows you to see the scope of the applicability of each type of engines.

PUVD - pulsating air-jet engine, TRD - turbojet engine, PVR - direct-flow air jet, GPVD - hypersonic direct-flow air jet engines characterize a number of parameters:

specific traction - The relationship created by the thrust engine mass flow fuel;
specific weight - The ratio of the motor thrust to the engine weight.

Unlike rocket enginesThe thrust of which does not depend on the speed of the rocket movement, the thrust of air-jet engines (VDD) strongly depends on the flight parameters - height and speed. It was not yet possible to create a universal VDD, so these engines are calculated under a certain range of working heights and speeds. As a rule, overclocking VD to the operating range of velocities is carried out by the carrier itself or the starting accelerator.

Other pulsating VD

Besleless Pavd

The literature meets the description of engines like PUVD.

Bindless PavdOtherwise - U-shaped PUVDs. There are no mechanical air valves in these engines, and so that the inverse movement of the working fluid does not lead to a decrease in the thrust, the motor path is performed in the form of the Latin letter "U", the ends of which are turned back along the movement of the device, while the expansion of the jet jet occurs immediately from both ends tract. The flow of fresh air into the combustion chamber is carried out due to the wave of the vacuum arising after the pulse and the "ventilating" camera, and the sophisticated form of the path is used for the best execution of this function. The lack of valves allows you to get rid of characteristic flaw The valve Pavdra is their low durability (on the FAU-1 aircraft of the valve fau-1 burned approximately after half an hour, which was enough to perform its combat missions, but absolutely unacceptable for the reusable apparatus).

Detonation Pavd

The scope of PUVD.

PUVD is characterized by both noisy and uneconomical, but simple and cheap. High level Noise and vibrations follows from the most pulsating mode of its operation. The extensive torch, the "hitting" from the Pavdde nozzle, is evidenced by the uneconomical nature of the use of fuel - the result of incomplete combustion of fuel in the chamber.

A comparison of PAUD with other aviation engines allows you to quite accurately determine the scope of its applicability.

PUVDD is many times cheaper in production than gas turbine or piston engine, therefore, with one-time application, it wins it economically (of course, provided that it "copes" with their work). With long-term operation of a reusable apparatus, PUDD loses to the economically of the same engines due to wasteful fuel consumption.

Valve, as well as baptized, PUVDs are distributed in amateur aviation and aircraft modeling, due to simplicity and low cost.

due to the simplicity and low cost, small engines of this type have become very popular among aircraft modelists, and in amateur aviation, and commercial firms producing Pavdde and valves for sale for these purposes (a spelling spare part) appeared.

Notes

Literature

Video

Steam engine Stirling's engine Pneumatic Engine

According to the type of work body

Gas	Gas turbine installation Gas turbine power station Gas turbine engines
Steam	PARKAZATION INSTALLATION Condensation turbine
Hydraulic turbines	Propeller turbine

The Liaulka's experimental design bureau has developed and experienced an experimental sample of a pulsating resonator detonation engine with a two-stage kerosene-grain mixture. According to the average measured motor thrust made up about a hundred kilograms, and the duration of continuous operation ─ more than ten minutes. Until the end of this year, the OKB intends to make and test a full-size pulsating detonation engine.

According to the chief designer OKB named after Lulleka Alexander Tarasova, during the tests, modes of work characteristic of turbojet and direct-flow motors were simulated. The measured values \u200b\u200bof the specific thrust and the specific fuel consumption were 30-50 percent better than that of ordinary air-jet engines. During the experiments, it was repeatedly turned on and off the new engine, as well as control of thrust.

In the future, on the basis of new technologies, engines can be created for rocket-space systems and combined power plants of aircraft capable of performing flights in the atmosphere and beyond.

The fact that in Russia work is underway to create a pulsating detonation engine, in March 2011. This was then stated by Ilya Fedorov, managing director of the Saturn Scientific and Production Association, which includes chalki OKB. What kind of type of detonation engine was speech, Fedorov did not specify.

Currently, three types of pulsating engines ─ valve, bauble and detonation are known. The principle of operation of these power plants is the periodic supply to the combustion chamber of fuel and the oxidizing agent, where the fuel mixture is ignited and the expiration of combustion products from the nozzle with the formation of reactive traction. The difference from conventional jet engines is the detonation combustion of the fuel mixture, in which the burning front spreads faster than the sound speed.

The pulsating air-jet engine was invented at the end of the XIX century by the Swedish engineer Martin Viberg. The pulsating engine is considered simple and cheap in the manufacture, however, due to the peculiarities of the fuel combustion ─ low-tech. For the first time, the new type of engine was used serially during World War II on German Winged Rockets FAu-1. ARGUS-WERKEN company ARGUS AS-014 was installed on them.

Currently, several large defense firms of the world are engaged in research in the field of creating highly efficient pulsating jet engines. In particular, the works are conducted by the French company Snecma and American General Electric and Pratt & Whitney. In 2012, the US Navy Research Laboratory on the intention to develop a spin detonation engine, which will have to replace ordinary gas turbine power plants on the ships.

Spin detonation engines differ from pulsating the fact that the detonation burning of the fuel mixture in them is continuously ─ the combustion front moves in the ring combustion chamber in which the fuel mixture is constantly updated.

The pulsating air jet engine (PAUD) is one of the three main varieties of air-jet engines (VDD), the feature of which is a pulsating mode of operation. Pulsation creates a characteristic and very loud sound, which is easy to find out these motors. In contrast to other types power aggregates Pavda has the most simplified design and low weight.

Building and principle of action of PAUD

The pulsating air jet is a hollow channel, open from two sides. On the one hand, an air intake is installed at the entrance, behind it - a traction unit with valves, then there is one or more combustion chambers and nozzle through which the jet stream comes out. Since the operation of the engine is cyclical, it is possible to allocate its main tacts:

inlet tact, during which the input valve opens, and the air is inserted into the combustion chamber under the action of discharge. At the same time, fuel is injected through the nozzles, as a result of which the fuel charge is formed;
the resulting fuel charge flammives from the spark of the spark plug, gases are formed during the combustion high pressureunder the action of which the intake valve is closed;
with the valve closed, the combustion products go through the nozzle, providing reactive traction. At the same time, in the combustion chamber at the exhaust of the exhaust gases, the discharge is formed, the input valve automatically opens and admits inside the new air portion.

The engine input valve may have different designs and appearance. Alternatively, it can be made in the form of blinds - rectangular plates fixed on the frame, which are opened and closed under the action of the pressure drop. Another design has a flower shape with metal "petals", located in a circle. The first option is more efficient, but the second is more compact and can be used on small-scale structures, for example, with aircodellize.

Fuel supply is carried out by nozzles that have a check valve. When the pressure in the combustion chamber decreases, a portion of fuel is supplied, when the pressure increases due to the combustion and expansion of gases, the fuel supply is stopped. In some cases, for example, on low-power motors from aircamodes, nozzles may not be, and the fuel supply system is reminded by a carburetor engine.

The ignition candle is located in the combustion chamber. It creates a series of discharges, and when the concentration of fuel in the mixture reaches the desired value, the fuel charge flames. Since the engine has a small size, its walls, made of steel, in the process of work are quickly heated and can fuel the fuel mixture is not worse than the candle.

It is not difficult to understand that for the launch of PUVD, you need an initial "push", in which the first portion of the air will fall into the combustion chamber, that is, such engines need pre-acceleration.

History of creation

The first officially registered development of PAUD refers to the second half of the XIX century. In the 1960s, two inventors immediately managed to get patents to a new engine type. Names of these inventors - Telshov N.A. And Charles de Lumury. At that time, their development was not widely used, but at the beginning of the twentieth century, when a replacement was found for aircraft piston enginesGerman designers drew attention to Pavdde. During World War II, the Germans were actively used by the FAU-1 aircraft, equipped with Pavda, which was explained by the simplicity of the construction of this power unit and its low cost, although on its working characteristics he was inferior to even piston engines. It was the first and only time in history when this type of engine was used in the mass production of aircraft.

After the end of the war, PUVD remained "in military affairs", where they found the use as a power unit for the air-surface type missiles. But here over time they have lost their positions due to speed limitations, the need for initial overclocking and low efficiency. Examples of using PUVD are Rockets FI-103, 10X, 14X, 16X, JB-2. IN last years There is a renewal of interest in these engines, new developments aimed at its improvement appear, so that in the near future, PUVD will again become in demand in military aviation. At the moment, the pulsating air-jet engine is returned to life in the field of modeling, thanks to the use of modern structural materials.

Features Pavd

The main feature of Pavdards, which distinguishes it from its "closest relatives" of turbojet (TRD) and direct-flow air-reactive motor (PVRD), is the presence of an intake valve in front of the combustion chamber. It is this valve that does not pass back the products of combustion, determining their direction of movement through the nozzle. In other types of motors, there is no need for valves - there air enters the combustion chamber under pressure due to pre-compression. This, at first glance, a minor nuance plays a huge role in the work of Pavds from the point of view of thermodynamics.

The second difference from the TRD is cyclicality. It is known that in the TRD, the process of burning fuel passes almost continuously, which provides even and uniform reactive traction. Pavdde works cyclically, creating oscillations inside the design. To achieve maximum amplitude, it is necessary to synchronize the oscillations of all elements, which can be achieved by selecting the desired nozzle length.

In contrast to the direct-flow air jet engine, the pulsating air jet engine can work even at low speeds and being in a fixed position, that is, when there is no oncoming air flow. True, his work in this mode is not able to provide the magnitude of the reactive thrust required for the start, therefore aircraft and rockets equipped with PUVDs need initial acceleration.

Small video launches and works Pavd.

Types of Pavd

In addition to the usual Pavdde in the form of a straight-line channel with an inlet valve, which was described above, there are also its varieties: bauble and detonation.

Bindless PUVD, as it is clear by his name, does not have an inlet valve. The reason for its appearance and use was the fact that the valve is a rather vulnerable part, which is very quickly fail. In the same version " weak link»Eliminated, therefore, the service life is extended. The design of the balanced Pavdde has the shape of the letter U with the ends, directed back along the reactive thrust. One channel is longer, he "answers" for the craving; The second is shorter, it enters the air into the combustion chamber, and when combustion and expansion of working gases, part of them goes through this channel. This design allows the best ventilation of the combustion chamber, does not allow the fuel charge leakage through the inlet valve and creates an additional, albeit insignificant, craving.

without a clapping version of the execution of PUVD
without valve U-shaped PURVD

The detonation Pavda implies the burning of the fuel charge in the detonation mode. Detonation involves a sharp increase in the pressure of combustion products in the combustion chamber at a constant volume, and the volume itself increases already when the gas moves along the nozzle. In this case, the thermal increases Efficiency engine In comparison, not only with the usual PAUD, but also with any other engine. At the moment, this type of motors is not used, but is at the stage of development and research.

detonation PURVD

Advantages and disadvantages of Pavdde, scope of application

The main advantages of pulsating air jet engines can be considered their simple design, which pulls their low cost. It is these qualities that caused their use as force aggregates on military rockets, unmanned aircraft, flying targets, where there are not durability and ultra-speed, but the ability to install a simple, light and cheap motor capable of developing the desired speed and deliver an object to the target. The same qualities brought PUUL's popularity among aircraft carrier lovers. Lightweight and compact engines, which, if desired, can be made independently or buy at an affordable price, are well suited for aircraft models.

The disadvantages of the PAUD is a lot: an increased level of noise when working, uneconomic fuel consumption, incomplete combustion, limited speed, vulnerability of some structural elements, the same as the inlet valve. But, despite such an impressive list of minuses, PUVD is still indispensable in their consumer niche. They are the perfect option for "disposable" purposes, when there is no point in setting more efficient, powerful and economical power units.