RU59738U1 - DETONATION ENGINE WITH MAGNETIC-DYNAMIC CONTROL DEVICE - Google Patents

Abstract

A detonation engine with an electromagnetic control device relates to pulsating air-jet engines with resonant combustion chambers, to combined ramjet pulsating air-jet engines, as well as to detonation engines. The objective of the utility model is to increase the reliability of the detonation engine and improve its characteristics due to the effective impact on the chamber processes by additional ionization of the fuel-air mixture. The technical result that can be obtained using the utility model is to organize a continuous pulse cycle of the detonation engine. The task is achieved in that the detonation engine with an electromagnetic control device consists of a fuel supply system, a control system, a detonation chamber, an initiator and an MHD generator. At the same time, an ionization device was installed in front of the initiator, the input of which is connected to the control system, and the MHD generator is placed around the cylindrical part of the detonation chamber in the region of its front bottom over ring semi-closed magnets and rotated 90 ° relative to them and connected through the control system with the initiator. To increase the electrical conductivity of the air-fuel mixture with the help of an ionization device, easily ionizing substances are introduced into the chamber: calcium, sodium or cesium. When an ionized detonation wave moves through ring semi-closed magnets and an MHD generator, the ions experience the Lorentz force, which redistributes the ion concentration. On one side of the MHD generator, positive charges arise, and on the other side, negative charges. The resulting Kholovskaya potential difference is transmitted to the initiator through an amplifying-converting device. Thus, the proposed detonation engine with a magnetogasdynamic control device provides an increase in the reliability of its operation, as well as an improvement in its characteristics due to the effective effect on the in-chamber processes. In addition, the implementation of this principle of engine operation simplifies its design, reduces overall dimensions and weight, reduces the cost of external energy required to trigger the initiator and prevents the penetration of the detonation wave into the fuel supply system. 2 ill.

Description

The utility model relates to pulsating air-jet engines with resonant combustion chambers, as well as to combined ramjet pulsating air-breathing engines. There is experience in the development of jet engines in which the accelerating chamber is made in the form of an expanding nozzle. This embodiment of the chamber contributes to supersonic acceleration of the combustion products. Of the chemical rocket engines, pulsed air-jet engines are close to the declared one. However, they have a large specific fuel consumption and a small specific impulse. These engines operate at a fixed frequency, since the combustion of fuel occurs in an acoustic type chamber. For example, the engine according to US patent No. 3727409, 1973.

Partially, these disadvantages are eliminated in RF patent No. 2066778, IPC F 02 K 7/04, 1993. In it, the detonation process is intensified by increasing the frequency of detonation pulses. This is achieved by the fact that the detonation excitation system is a prechamber with a gas-dynamic valve. However, this device has limited use, since the process of mixture formation occurs in the chamber after the supply of fuel components, and the operation of the initiation system is associated with the operation of the supply and mixture formation systems and is pulsed from an external power source.

The closest to the principle of operation and technical device is "Pulsating detonation engine with a closed cycle" (certificate of the Russian Federation for utility model No. 20549, IPC F 02 K 7/04, F 42 D 1/04, 2001). In it, an increase and regulation of the frequency of detonation pulses was carried out by organizing a closed cycle of the engine, which means such operation of the engine, when it continues to work automatically and autonomously after applying the initial pulse, that is, without using an external energy source. This is achieved by the fact that the initiation system is a magnetogasdynamic generator (MHD generator) located in the area of the nozzle and connected through an amplifying-converting device to the initiator.

The disadvantages of this device is the installation of the MHD generator in the area of the nozzle of the engine chamber, because the highest temperature is reached at the end of its cylindrical

parts, which does not contribute to the enhancement of ionization, as well as the possibility of penetration of the detonation wave into the fuel supply system.

The objective of the utility model is to increase the reliability of the detonation engine and improve its characteristics due to the effective impact on the chamber processes by additional ionization of the fuel-air mixture.

The technical result that can be obtained using the utility model is to organize a continuous pulse cycle of the detonation engine and to reduce the cost of external energy needed to trigger the initiator.

The task is achieved in that the detonation engine with a magnetogasdynamic control device consists of a detonation chamber, fuel supply and control systems, as well as an initiator and an MHD generator. At the same time, an ionization device was installed in front of the initiator, the input of which is connected to the control system, and the MHD generator is placed around the cylindrical part of the detonation chamber in the region of its front bottom over ring semi-closed magnets and rotated 90 ° relative to them and connected through the control system with the initiator.

Figure 1 presents the structural layout of the detonation engine with a magnetogasdynamic control device, figure 2 - the principle of operation of the measuring part of the MHD generator, figure 3 - position of the detonation wave at the time of the signal to the initiator, figure 4 - position detonation wave at the time of its passage through the MHD generator. The main elements of the detonation engine include:

1 - detonation chamber,

2 - fuel supply system,

3 - control system,

4 - ring semi-closed magnets,

5 - MHD generator,

6 - amplifier-converting device

7 - initiator,

8 - ionization device,

9 - inlet.

Detonation chamber 1 is designed to convert chemical energy

working fluid into the kinetic energy of detonation products. It is a tubular structure, at one end of which there is a fuel supply system, and from the other, the output of detonation products.

Fuel supply system 2 is intended for high-quality mixing of fuel components in order to form a fuel-air mixture and supply it to a detonation chamber under pressure.

The control system 3 is intended for organizing the starting processes, engine operation in a given mode and turning it off, as well as for converting the voltage taken from the MHD generator into a signal for triggering the initiator.

Semi-closed ring magnets 4, an MHD generator 5, an amplifier-converting device 6 of the control system 3, an initiator 7, and an ionization device 8 form an initiation system that is designed to initiate, maintain and control the detonation process in the detonation chamber 1. Elements are located in the following sequences on the detonation chamber 1 in the direction of gas flow: a device for injecting a fuel-air mixture in the form of an inlet 9, ring semi-closed magnets 4 joint about with an MHD generator 5, the ionization device 8 and initiator 7 (Figure 1). In this case, the initiator 7 is located closer to the ring semi-closed magnets 4 and the MHD generator 5.

In the initial state, in the case of using permanent magnets in the detonation chamber 1, a constant magnetic field is formed, the induction vector of which directed as shown in figure 3. A pair of magnets located on opposite sides of the detonation chamber 1 creates a magnetic flux whose magnetic induction vector is perpendicular to the movement of the detonation wave, i.e. perpendicular to the axis of symmetry of the detonation chamber 1. Permanent magnets do not require additional sources of electricity, but electromagnets can also be used.

The principle of operation of magnetogasdynamic control. For simplicity, we consider the device of magnets 4 and MHD generator 5, made in the form of rectangular plates and located at 90 ° with respect to each other, and also perpendicular to the movement of the detonation wave (figure 2).

In the detonation chamber 1, when the fuel-air mixture is detonated, a high temperature is created (up to 3500 K), at which the gaseous detonation products are partially ionized, forming an electron-ionic cold plasma. To increase its electrical conductivity, an ionization device 8 is used. To this end, in

easily ionizing substances are introduced into the fuel-air mixture: calcium, sodium or cesium. A high-temperature detonation wave moves through a fuel-air mixture located in detonation chamber 1. At the same time, its internal energy is converted into the kinetic energy of detonation products, the velocity of which increases to 2000 m / s or more. Like a metal conductor, detonation products are generally neutral. The detonation wave is directed along the axis of the detonation chamber 1. Once in a region of a strong magnetic field, it undergoes the Hall effect, the essence of which is as follows. When an ionized detonation wave moves under the influence of a magnetic field ions experience the Lorentz force F _l , under the influence of which a redistribution of the concentration of ions occurs. On one side of the MHD generator, positive charges arise, and on the other side, negative charges.

In idle mode, when the external circuit is open, the largest potential difference equal to the EMF occurs between the electrodes. Depending on the design of the generator, it can reach several hundred or thousands of volts. The power released in the external circuit is used to power the initiator. The resulting Kholovskaya potential difference is transmitted to the initiator 7 through the amplifying-converting device 6. In this case, the electrons moving along the external circuit to the initiator 7 return to another electrode, where positive ions are neutralized.

The following modes of operation of the detonation engine with a magnetohydrodynamic control device are possible: start mode, operating mode and shutdown mode. Let us consider each of them sequentially.

The start mode is carried out by simultaneously supplying a signal to the fuel supply system 2, the ionization device 8 and with a certain time delay to the initiator 7 (figure 3).

In this case, the air-fuel mixture with the specified values of the parameters through the inlet 9 enters the detonation chamber 1. The degree of filling of the detonation chamber 1 is calculated from its total length, the relative feed rate of the air-fuel mixture and the propagation velocity of the detonation wave. After the detonation chamber 1 is completely filled, the control system 3 sends a signal to the initiator 7, which generates a detonation pulse, under the influence of which the fuel-air mixture located in the detonation chamber 1 is initiated.

A change in the state of the fuel-air mixture during detonation occurs in

two stages. Initially, the mixture is compressed by the detonation wave almost instantly without changing the composition of the mixture and the release of energy. Then, immediately after the front of the detonation wave, whose width is approximately equal to the mean free path of the molecules (10 ^-7 ... 10 ^-8 cm), an ultrafast chemical reaction is initiated and begins to occur, accompanied by heat generation and the formation of the final detonation products. Therefore, immediately beyond the plane of the front of the detonation wave there is a zone of chemical reactions, the width of which in the case of gas mixtures is approximately equal to several millimeters. Behind the zone of chemical reactions is the region where the reaction has mainly already occurred (detonation products). Moreover, upon initiation, two detonation waves are formed (ДВ1 and ДВ2), which move along the fuel-air mixture in different directions (Fig. 3).

Work mode. It is characterized by a continuous pulsed detonation process, in which the air-fuel mixture is constantly supplied to the detonation chamber 1, and the MHD generator 5 sends signals to trigger the initiator 7.

The detonation wave ДВ1 moves towards the front bottom, and the detonation wave ДВ2 - towards the open end of the detonation chamber 1 with a speed equal to the Chapman-Jouguet detonation speed (Fig. 4).

In front of the front of motion of the detonation wave ДВ1 there is an ionized fuel-air mixture, because The ionization device has tripped 8.

Further, the detonation wave ДВ1 is directed along the axis of the detonation chamber 1 towards its front bottom and falls into the area of influence of the ring semi-closed magnets 4 and the MHD generator 5. Passing through the MHD generator, the Holovskaya potential difference arises, which is transmitted to the initiator through the amplifying-converting device 6 7. On the other hand, getting into the region of a strong magnetic field, the DV1 form undergoes deformation, which contributes to its destruction and prevents its further movement and penetration into the system. ivopodachi fuel-air mixture. In turn, this eliminates the detonation of the fuel-air mixture.

When the detonation wave ДВ2 leaves the detonation chamber 1, detonation products with high temperature and pressure remain in it. When the detonation wave DV2 leaves the detonation chamber 1, a pressure drop is formed at the open end. This pressure difference creates a series of rarefaction waves, which, propagating in the chamber at the speed of sound, remove the detonation products.

The further detonation cycle is carried out automatically through the implementation of

intracameral gas-dynamic communication.

The engine is turned off by supplying a signal from the control system 3 to the fuel supply system to stop the flow of the fuel-air mixture into the detonation chamber 1.

Thus, the combination of a detonation engine with a magnetogasdynamic control device with an additional ionization device will significantly improve engine performance, including increasing engine efficiency due to more complete use of the working fluid energy, as well as organizing a continuous pulsed detonation process. In addition, the implementation of this detonation engine operation cycle contributes to the simplification of its design, reduction of dimensions and mass, reduction of external energy costs necessary for triggering the initiator and preventing the detonation wave from penetrating the fuel supply system.

Claims (1)

A detonation engine with a magnetogasdynamic control device, consisting of a fuel supply system, a control system, a detonation chamber, an initiator and an MHD generator, characterized in that an ionization device is further introduced located in front of the initiator, the input of which is connected to the control system, and the MHD generator is located around the cylindrical part of the detonation chamber in the region of its front bottom over annular semi-closed magnets, rotated relative to them by an angle of 90 ° and connected through a control system interaction with the initiator.