RO128535A2 - Ionic propulsion system - Google Patents

Abstract

The invention relates to an ionic propulsion system for supersonic engines. According to the invention, the ionic propulsion system comprises a liquid fuel tank () which supplies, through a classic channel (), a jet engine () and, through an additional channel (), an electric generator () which provides the high voltage required for acceleration of positive ions in the plasma generated by the fuel combustion within a combustion chamber. In one embodiment, for a static jet engine, the ion acceleration is obtained by the electric separation of the combustion chamber () from the exhaust system () while applying an adjustable voltage in the range of 10...500 kV between the two compartments. In another embodiment, for a turbojet engine, the ion acceleration is obtained by introducing into the postcombustion chamber a positively charged electrode as compared with the exhaust nozzle which becomes a negative electrode, and applying a voltage in the range of 10...500 kV between the two electrodes.

Description

The invention relates to an ion propulsion system for supersonic engines.

The state of knowledge

The supersonic engines currently used are turbojet or stator type. Reaction propulsion requires three processes: compression, combustion and release of working fluid. Generally, a reactor engine has as a working fluid the air and as a propulsion plant the inlet device, the combustion chamber and the exhaust system or the reaction nozzle.

In the study of a system with mechanical compression of the working fluid, known as turbojet engine, it was observed that there is a value of the compression degree K ' _c for which the system-specific propulsion force is maximum. If the speed of flight increases, the compression degree decreases so that, at a certain flight speed V _max will result in ^π _c , ~ 1 · Mechanical compression stops, the turbocharger group of the system becomes useless. As a result, for V - L _max flight speeds, air compression is done dynamically, inside another system called stator jet engine.

The turbojets are known as mechanical compression propulsion systems and are used on aircraft evolving at speeds <2.5M.

Stator reactors or stator reactors are known as dynamic compression propulsion systems and are used to drive helicopter blades or in combination with turbocharged engines on aircraft evolving at speeds of> 2.5M.

The propulsion plant of a turbojet includes the compressor-turbine pair for adjusting the pressure along the flow path of the working fluid. The stator reactor propulsion plant is in fact a simple profiled pipeline in which the three processes required for reaction propulsion are performed (λ-2 3 1 1 - 0 1 2 0 9 ”52

3 -11- nozzles in the inlet device, which can be fixed or adjustable, mechanical compression with compressor or dynamic of the air is realized by continuous or discontinuous braking, in order to achieve a static pressure favorable to a stable combustion in the combustion chamber.

The combustion chamber is the section of the working channel where the chemical energy of the air-fuel mixture is converted into thermal energy, by combustion.

After combustion in the combustion chamber, a flue gas expansion occurs. At the turbocharger engine the expansion takes place in the turbine, the only element in the engine that produces mechanical work necessary for all the component parts of the engine. Incomplete flue gases are discharged through a profiled, fixed or adjustable exhaust device. In order to increase traction, in some cases, between the turbine and the exhaust nozzle, there is an area where a new combustion injection is made to initiate an additional combustion process, known as the post-combustion chamber. In the stator reactor, the flue gas expansion is made in the exhaust nozzle which can also be fixed or adjustable. The flow regime is supersonic, regardless of the flow regime in the other sections of the engine. in the minimum section of the reaction nozzle the critical flow rate is reached. Compared to a turbocharged engine, the dynamic compression propulsion system has a propulsion force of 4-6 times higher, a weight of 2-3 times lower, the working fluid temperature can take values comparable to the combustion temperature of the mixture air-fuel and the chemical composition of the fuel is no longer critical.

The disadvantages of dynamic propulsion systems are the following:

1. Low efficiency;

2. The propulsion force decreases with height due to the decrease in air density.

Short description

The ion propulsion system according to the invention removes the above disadvantages by the fact that, in the electric field, the positive plasma ions produced by the combustion of the fuel in the direction of the exhaust nozzle are obtained by electrically separating the combustion chamber from the exhaust system in the case of the stator engine. in one embodiment or, by inserting in the after-chamber a electrode which is positively charged to the exhaust nozzle in the case of the turbojet engine, in another embodiment, and the application of an adjustable voltage in the voltage range V = (10 ... 500) KV between the two compartments in the first variant and between the electrode and the outlet nozzle in the other variant, in order to increase <ν? Ο 11 - ο 1 2 0 9 - 2 3 -II- m _{tl of the} output, allowing the reactor engine to continue to operate in a pressure zone that can be evaluated below 20 mBarr (2KPa). The required electricity comes from an electric generator powered from the same fuel source as the reactor engine. The electrical behavior of the assembly can be improved if the cathode is coated with a thermo-emissive electron material so as to obtain a discharge of the type of gas tubes.

The kinetic energy per particle in the working fluid for various flow rates at the motor output in the absence of electric acceleration are presented in table no. Were used: E _c = m _p v ^2/2, v = a multiple of the speed of sound under normal conditions of temperature and pressure, m is the mass average particle of ionized gas, mp = 28.9 amu = 47.974 to 10 ^{- 27} Kg for air, mp '= 30.95 uam = 51.3 77-10 ^-27 Kg for air 90% and CO2 10%, m _p ² = 32.4 uam = 53.784-10 ^-27 Kg for air 80% and 20% CO2.

The energies of the ionized particles in the electric field created are presented in table no.2.

They used:

E _e = qV, where: q = ^{1.610 -9} C for single ionized particles, q = 3.2-10 ^-19 C for double ionized particles.

Table no

V And _c ° E _c ' E _c ² (340xms ^-2 ) (10 ^-2l xj) (io ^{-21 x} j) (IO ^-21 XJ) 1 2.7728972 2.9695906 3.1087152 2 11.0915888 11.8783624 12.4348608 3 24.9560748 26.7263154 27.9784368 4 44.3663552 47.5134496 49.7394432 5 69.32243 74.239765 77.71788 6 99.8242992 106.9052616 111.9137472

The ratio between single and double ionized particles was considered in turn:

Table no. 2

U (KV) Ee '(10 ^-l6 -j) Ee ² (10 ^-l6 -j) E _e ³ (10 ^-l6 -j) 10 16 17 18 20 32 34 35

^ 2 Ο 1 1-01 2 0 9 -2 3 -11- 2011

2. (0.95: 0.05), 50 80 84 88 3. (0.9: 0.1). 100 160 168 176 two hundred 320 336 352 500 800 840 880

It is observed that E _is obtainable is significantly higher than E _c , but the correct value requires adjustments according to the ionization degree of the plasma produced by the combustion of the fuel. Basically, the energy obtained by the electric path becomes dominant throughout the propulsion system, the flame being used primarily as a primary ion generator.

In order to maintain the electric acceleration field, a generator set capable of providing the necessary power must be provided.

The reactor engine equipped with the ion propulsion system according to the invention has the following advantages'.

1) The engine efficiency is increased;

2) The propulsion force is maintained under conditions of lower atmospheric pressure lower than 20 mBarr (2 KPa).

DETAILED DESCRIPTION OF THE INVENTION The device according to the invention is described in detail below, in relation to the figures which represent:

FIG. 1 block diagram of the ion propulsion system according to the invention.

FIG. 2 ionic propulsion system for the stator jet engine - longitudinal section

FIG. 3 Ion propulsion system for the turbojet engine - longitudinal section in Figure 1 showing an ion propulsion scheme according to the invention, from a liquid fuel tank 1 is fed through a conventional channel 2 a reactor engine 3. Through a channel In addition 4, an electric generator 5 is supplied which will provide the high voltage required to accelerate the plasma produced by the combustion of fuel in the reactor engine via a feed channel 6.

Figure 2 represents a longitudinal section by ion propulsion system for the stator engine according to the invention wherein the combustion chamber 11 is electrically separated from the exhaust system 14 by means of an annular ceramic insulator 12, a cermet resistant to high temperatures, for example, which can be fixed to the engine housing by a weld 13. The section from the combustion chamber, including the combustion chamber, is electrically insulated from (kl O 1 1 ~ O 1 2 O 9 - 2 3 -11- ZOII mass and rises to a positive potential adjustable by a connection 16 from a high voltage HV electrical generator The outlet section is connected to the ground by a connection 15. The electrical behavior of the assembly can be improved if the cathode material is thermo-emissive of electrons so that it get a discharge of the type of gas tubes.

Figure 3 shows a longitudinal section through an ion propulsion system for a turbojet engine in which, beyond the turbine 31, a titanium or steel ring 33, resistant to the exhaust gas temperature, as well as the turbine 31 is mounted in the post chamber. at the shelling of the particles of acetate gas. The ring is fixed to the motor housing by means of solid ceramic pieces 34, in a minimum number of 3 pieces, fixed by cord 34 welding. Inside the housing of the outlet nozzle 35 is deposited a thermo-emissive layer 38, tungsten carbide for example. Being electrically insulated from the motor housing, the ring 33 rises to a positive potential adjustable by means of a connection 37 with an HV electric generator. The deposition of thermo-emissive material 38 together with the whole engine is connected to the ground via a connection 36.

The potential difference can vary in both variants in the range (10 ... 500) KV, forming two electric domains between which is the acceleration volume. The required electricity comes from a dedicated electric generator, powered from the same fuel source as the reactor engine.

In the case of the stator jet engine, when starting from idle (vo = O), the acceleration voltage is applied before the ignition. The plasma produced by combustion in the combustion chamber is accelerated and the volume of air in the combustion chamber is directed to the outlet nozzle. Once the movement of the fluid inside the stator jet engine is initiated, a tractor force is developed that sets the aircraft in motion. As the aircraft speed increases, the pressure in the air intake system increases and the regime begins to sign with a classic stator jet engine. A calculator is necessary for the control of the voltage depending on the current absorbed so the density of loads in the working fluid and, implicitly, the altitude. Thus, as the flight height increases and the atmospheric pressure decreases, the acceleration voltage will increase to compensate for the decrease in the number of particles by increasing the pulse per particle. in this way the tensile force of the engine is maintained.

Oy-2 0 1 1 - 0 1 2 0 9 -2 3 -11- 2011

An example of the application of the ionic acceleration system according to the invention is shown below, in connection with Figures 4 and 5.

Example

On an experimental and non-optimized installation, between two rings of different diameters from the type shown in figure 5, a propane flame injected into a 10TNC steel tube represented in figure 4. was accelerated ionically. The tube is 400 mm long and Φ = 100 mm. Each ring 41 was fixed by means of rods 42 and electrical insulators 43 of the tube housing. The rings and rods were also made of 10TNC steel. The dc ring Φ = 50 mm was fixed in the holes 21 and was connected to the table, becoming a cathode. The Φ = 30 mm ring was fixed in the holes 22 and the flame injector was fixed in the holes 23 of the tube. The latter were connected to the positive terminal of a high voltage source.

Assuming that an electric generator has a yield of 30%, one can evaluate the amount of propane required to produce the electricity used. Knowing that the calorific power of propane is 50MJ / Kg, it turns out that the laboratory ionic accelerator has a consumption:

Q = 7.4 g / kN * sec

For comparison, the consumption of known engines is:

g / KN-sec., B747 engine

53.8 g / KN-sec. (M = 3.2), SR71 engine

225 g / KN-sec space shuttle engine

Claims (5)

1. Ion propulsion system according to the invention characterized in that the electric field accelerates the positive ions from the plasma produced by the combustion of the fuel in the combustion chamber in the direction of the exit nozzle by electrically separating the combustion chamber from the exhaust system with a ceramic insulator and the application of an adjustable voltage in the voltage range V = (10 ... 500) KV on both sides of the insulator. An ion propulsion system according to claim 1, characterized in that it uses an electric generator powered from the same fuel source as the engine. 3. Ion propulsion system according to the invention, characterized in that the electric field accelerates the positive ions from the plasma produced by the combustion of the fuel in the combustion chamber in the direction of the output nozzle by introducing a positively charged electrode into the after-chamber. by the discharge nozzle and the application of an adjustable voltage in the voltage range V = (10 ... 500) KV between the positive electrode and the discharge nozzle. 4. Ion propulsion system according to claim 2, characterized in that it uses an electric generator powered from the same fuel source as the engine. 5. Ion propulsion system according to claim 2, characterized in that it uses for the cathode a material with high thermoelectric emission for increasing the ionization degree in discharge.