DE102016123092B3 - Rocket engine - Google Patents

Abstract

The present invention relates to a rocket engine for a rocket fuel, with a support mass upon combustion of which a product with a dipole moment is produced, comprising a combustion chamber, in particular with a flame holder, a nozzle and a device for generating an electric field, with which at least in a region of the nozzle an electric field can be applied.

Description

The present invention relates to a rocket engine. In particular, the invention relates to a rocket engine for a rocket fuel, with a support mass in the combustion of which a product is formed with a dipole moment.

Rocket engines are drives that generate the drive force (thrust) by ejecting support mass against the drive direction. Because they do not suck in matter from the outside and accelerate it again, they work independently of the environment, even in a vacuum. They were originally developed for the flight of rockets.

In the US5170623A a hybrid chemical / electromagnetic propulsion system is described.

In the US2013 / 0327015A1 describes a dual-use hydrazine propulsion system.

An essential characteristic of rocket engines is the mass-specific momentum, which describes the efficiency of the drive as the ratio between momentum and fuel mass consumed. He has - in SI units - the unit m / s and is z. B. in a solid motor at 2450 m / s, a liquid engine at 4444 m / s. In addition one speaks of the weight-specific impulse, if one normalizes the mass-specific impulse over the Erdbeschleunigung. The SI unit of the weight-specific pulse is s.

There are currently two ways to increase the (weight) specific impulse of chemical engines: free radicals and metastable elements. All methods are still in the experimental stage. Although ozone is unstable, the Allotrop Tetrasauerstoff should be more stable. This would allow (weight) specific pulses of up to 564 s (5538 Ns / kg) in vacuum. One also tries to use hydrogen radicals as fuel. To increase the stability of the element, they are mixed under liquid hydrogen. If this combination (with theoretical 15.4% radicals) is burnt with liquid oxygen, (weight-) specific impulses of up to 750 s (7358 Ns / kg) can be achieved in vacuum. Metastable helium was produced on a test basis and stored as a Bose-Einstein condensate. The reaction of metastable helium to helium would make specific pulses of 2825 s (27,713 Ns / kg) possible, more than with nuclear propulsion. In particular, rocket engines must allow a large enough mass flow rate that exotic combinations fail on a regular basis, such as a 100,000 kg rocket with a high weight pulse of 10,000 s and a maximum throughput of only 100 g / s (ion engine) do not use for LEO or GEO space travel.

It is the object of the present invention to provide a rocket engine with increased efficiency.

This object is achieved by the features of claim 1. Advantageous embodiments are specified in the dependent claims.

Thereafter, the object is achieved by a rocket engine for a rocket fuel, with a supporting mass in the combustion of a product with a dipole moment arises, comprising a combustion chamber preferably with a flame holder, a nozzle, wherein means for generating an electric field is provided with the at least an electric field is applied in a region of the nozzle which restricts transverse and rotational degrees of freedom of the molecular motion of the molecules with dipole moment and the molecules with dipole moment are rectified as it travels through the electric field.

The work of the rocket engine is based on the recoil principle in the context of the third Newtonian axiom. The higher the speed of the ejected support mass, the more efficient the engine and the greater the potential speed change "delta v" of the missile. Rocket engines are used not only as propulsion systems for rockets, launchers, spacecraft, but also for aircraft and special land vehicles (eg rocket cars). Recoil drives based on combustion carry both their fuel and their oxidizer. The driven object, for example, a rocket, is accelerated forward by the recoil with the same force that ejects the drive medium to the rear.

Most (but not all) rocket engines are internal combustion engines: by burning a fuel with oxidants, they heat a support mass (typically the combustion product (s)) in a very high temperature combustor and pass the high energy product of the process in gaseous form to emerge an opening. The thermal energy released in the (exothermic) combustion as well as the resulting pressure in the combustion chamber are (partially) converted into kinetic energy (acceleration) and thus generate the thrust force according to the recoil principle.

The specially shaped outlet of the combustion chamber is called nozzle, it serves to increase the exit velocity (resulting in higher thrust) and to increase the internal pressure in the combustion chamber (in favor of the combustion process). One frequently used type of nozzle is the Laval nozzle. The nozzle must be cooled, which is achieved either by coatings or by internal cooling lines through which the fuel flows. Ideally, the jet is expanded to the ambient pressure; in vacuum or for practical reasons (length and weight) this is not possible, the design of the nozzle is therefore a compromise and part of the drive design, which also depends on the operating conditions: in space, in orbit, on the way to orbit, in the higher atmosphere or in the atmosphere.

A chemical rocket engine works (unlike some other engines) completely independent of its environment. It is an internal combustion engine such as the air-breathing jet engine, but in contrast to this is not dependent on the atmospheric oxygen as an oxidant: There are all necessary resources carried, such. B. the oxygen necessary for the combustion of the fuel. The rocket can therefore work in a vacuum. The following three forms of chemical thrusters are common and different in the storage state of the resources: solid propellant, liquid engine, and hybrid rocket engine. The solid fuel engine uses solids to burn and the fuel tank is also the combustor. A liquid engine allows thrust regulation, long working hours and relatively low reuse due to its design. In liquid rocket engines, fuel and (unless it is a monolaser engine) oxidant are stored outside the engine. They can also be re-ignited with little additional effort, so that the engine can have several firing phases during the flight. The hybrid rocket engine uses both solid and liquid fuel components.

The propellants of the rocket engine or rocket engine are referred to as rocket fuel. It gives rise to the thrust of a rocket. The choice of rocket fuel is a determining factor for the specific momentum of a rocket engine. The specific impulse is a measure of the efficiency of engines, ie the consumption of fuel per pulse.

Although a high specific impulse is always desirable, less efficient fuels are often used. For example, in the first stage of rocket engines, kerosene is often used as fuel or solid rocket, although liquid hydrogen or electric propulsion engines have a much higher specific impulse, and thus are more efficient.

The fuels most commonly used for rockets are chemical. The products of a chemical reaction are expelled from the engine nozzle at high speed. Both energy and support mass come from the chemical reaction. This has e.g. proven in aerospace as a start system into orbit, because the achievable accelerations (6g) and the specific impulse and the necessary throughput are technically feasible.

In chemical fuel systems, a chemical reaction generates the thrust of the rocket. A distinction is generally either by the nature of the fuel in solid, liquid or hybrid fuels or by the number of reactants involved in the combustion process in Monergol, Diergol or Triergol. The chemical reaction releases heat energy and reaction products that create high pressures and temperatures in the combustion chamber, expelling the reaction products from the engine nozzle at the highest possible speed. In chemical rocket fuels, a fuel (also called fuel) and an oxidant or oxidant are preferably used. These can be present in mixed (solid rocket) or unmixed form (eg in a liquid rocket) before take-off.

Particularly in the case of large rockets, the following combinations are particularly preferred:

Cryogenic fuels such as kerosene with LOX (Liquid Oxygen, liquid oxygen), liquid hydrogen with LOX (Liquid Oxygen, liquid oxygen) are used for the drive. UDMH and / or hydrazine with dinitrogen tetroxide (hypergolic and storable without cooling) are used as liquid fuels. As solid propellants, hydroxyl-terminated polybutadiene with ammonium perchlorate and aluminum, abbreviated HTPB / AP / AL, are used.

For the situation control system only non-cryogenic substances are used: MMH with dinitrogen tetroxide or MON as hypergolic or hydrazine as monergol.

The support mass in recoil drives is the mass expelled backwards, causing the recoil. Thrust is the product of mass flow and exit velocity.

When burning the support mass, at least one product is formed with one Dipole moment. The dipole moment is a measure of the strength of a dipole molecule and thus of the polarity of the molecule. Such a product with dipole moment when burning the support mass may be, for example, water.

The combustion chamber is the component in which the fuel burns continuously with the oxidizer. In a solid rocket engine, this is the vessel in which the solid is introduced and burns; in a liquid rocket engine, this is a vessel, preferably made of metal, in which the fuel is mixed with the oxidizer and continuously burns. As a rule, combustion chambers are made cylindrical for production reasons. Particularly preferably, the combustion chamber of the present invention is formed with partially straight walls, preferably a container of rectangular, hexagonal, octagonal or square cross-section. This cross-section can be formed consistently over the entire combustion chamber, preferably be formed constant only in predetermined areas of the combustion chamber. The cross section may increase or decrease over the length of the combustion chamber. Preferably, the geometric basic shape of the cross section is obtained, even if it increases or decreases. At the front side, the nozzle opening opposite side of the combustion chamber, the injection head or an injector plate or a flame holder are preferably arranged. These have the task of intensively and finely mixing the fuel components brought up in separate pipes during the injection in order to ensure complete and complete combustion.

The combustion chamber is preferably immediately followed by a nozzle. The nozzle is preferably designed as a discharge nozzle, preferably in the form of a Laval nozzle. This consists of a constriction to increase the speed of the gas, the so-called nozzle throat, which in turn merges into a bell-shaped or conical part in which is generated by the expansion of the gases of the thrust. Preferably, combustion chamber and nozzle are manufactured in one part.

By the means for generating an electric field, it is possible to generate an electric field. An electric field is a physical field that acts on electric charges by the Coulomb force. It causes the binding of electrons to the nucleus and thus influences the shape of matter. Electric fields are caused by electric charges and by temporal changes of magnetic fields. The generated electric field is preferably the electric field of a point charge, particularly preferably of several point charges, preferably the electric field of a line charge, preferably the electric field of a dipole, particularly preferably the electric field of a surface charge, particularly preferably a homogeneous electric field, in particular the electric field a plate capacitor. Preferably, the means for generating an electric field is a plate capacitor.

Particularly preferably, an electric field is provided, which is arranged laterally. Thus, the otherwise free molecular motion of the dipole molecules is hindered or moderated in 3 of 6 degrees of freedom. This creates a possibility to direct the thermal energy more in the axial movement (= kinetic energy), as they supply the mass flow, especially in the form of a temperature increase.

More preferably, a quasi point charge is provided at the nozzle exit particularly preferably with a surface charge in the flame holder. In this case the E-field acts axially. In addition, 2 degrees of freedom are blocked.

Particularly preferably, the flow is moderated with the emergence of the dipole molecules until they exit the nozzle through an E-field. In this case, the electric field is, for example, with combustion up to the outlet cross section, preferably from the beginning of the combustion chamber to the nozzle outlet.

Further preferred is the combination of different E fields, for example axially and laterally oriented E fields.

Preference is also given to an oscillating E field, which is generated, for example, by alternating voltage - as a result of which any electrolysis effect or a one-sided load on the flow is reduced. A voltage change of up to 10,000 Hz is preferred; then the affected path length l = approx. 5,000 m / s / 10,000 1 / s = 0.5 m.

The device for generating the electric field is set up so that the electric field can be applied at least in a region of the nozzle. Preferably, the electric field in the entire region of the nozzle including the combustion chamber can be applied, particularly preferably at least in a part of the nozzle, particularly preferably in the region which faces the combustion chamber.

The electric field moderates the flow of dipole-like molecules through the nozzle, i. the transverse and rotational degrees of freedom (3 of 6) of the molecular motion of the dipole molecules is restricted, thereby improving the efficiency of the rocket engine. This can also be used when emptying containers.

In another embodiment of the present invention, the rocket engine is a liquid rocket engine.

In a further embodiment, the device for generating an electric field is designed so that in the region of the combustion chamber and in the entire region of the nozzle, an electric field can be applied. Due to the effect of the electric field not only at the nozzle but also in the area of the combustion chamber, the dipole molecules are moderated as they emerge in the exothermic reaction and also during the flow through the nozzle. The dipole moment prevents transverse and rotational movements of the dipole molecules in the flow and converts the energy into kinetic energy, i. in axial motion, improved; this improves the efficiency of the rocket engine. The electric field is preferably provided in the entire region of the combustion chamber and preferably also of the nozzle, more preferably behind the flame holder, particularly preferably from the inlet of the combustion chamber to the nozzle.

In a further embodiment, the device for generating an electric field is designed so that a static homogeneous electric field can be generated. This provides a field in which the molecules with the dipole element are rectified as they fly through this field, thereby reducing the counteracting motion of the individual molecules with one another.

Particularly preferably, the electric field has a thickness of more than 0.5 MV / m, preferably of more than 1 MV / m to, in particular more than 1.6 MV / m.

In a further embodiment, the device for generating an electric field is designed such that a variable electric field can be generated. Through a variable field, the molecules with dipole moment can be aligned either temporally variable or spatially differently. Thus, depending on the orientation of the field (axial / lateral), provision is made for the electric field to be time-changeable, for example oscillating at a fixed frequency or at a variable frequency. In the case of a lateral E field, it is preferably provided that the electric field can be changed continuously or else stepwise, preferably as a function of external conditions, for example possible maneuvers. Preferably, the electric field is also spatially differently modulated, i. preferably varies greatly along the longitudinal axis of the rocket engine in the region of the combustion chamber nozzle axis.

This makes it possible to better accompany the flow of the fluid of the molecules.

Further details and advantages of the invention will now be explained in more detail with reference to an embodiment shown in the drawings.

• 1 eine schematische Ansicht eines Ausführungsbeispiels eines Raketentriebwerks gemäß der vorliegenden Erfindung
• 2 einen Querschnitt durch ein Ausführungsbeispiel eines erfindungsgemäßen Raketentriebwerks
• 3 einen Querschnitt durch ein Ausführungsbeispiel einer Düse eines erfindungsgemäßen Raketentriebwerks

Show it:

• 1 a schematic view of an embodiment of a rocket engine according to the present invention
• 2 a cross section through an embodiment of a rocket engine according to the invention
• 3 a cross section through an embodiment of a nozzle of a rocket engine according to the invention

1 shows a schematic view of an embodiment of a rocket engine 1 according to the present invention. A rocket engine 1 includes a combustion chamber 10 and a nozzle 15 , In the combustion chamber is a catalytic flame holder 11 arranged as well as leads A and B for hydrogen and oxygen. In addition, there is a device for generating an electric field 20 intended.

By the device for generating an electric field 20 becomes an electrically positive charge on the upper side of the combustion chamber 10 and the nozzle 15 generated and an electrically negative charge on the lower side of the combustion chamber 10 and the nozzle 15 , As a result, an electric field is generated between the side of the combustion chamber shown above and the combustion chamber and the nozzle shown below.

If now hydrogen and oxygen are fed into the combustion chamber via the supply lines A and B and burned at the flame holder, the molecule water is formed, which is a dipole. This water molecule is aligned due to its dipole moment in the applied electric field and passed through the combustion chamber into the nozzle and ejected. By aligning the water molecules, the disordered heat movements of the water molecules are reduced and associated energy loss is avoided. This is how the rocket engine works 1 with a higher efficiency.

2 shows a cross section through an embodiment of a rocket engine according to the invention 1 , There are ceramic plates in this cross section 27 shown adjacent to metal plates 25 are arranged. A device for generating an electric field 20 generates a charge distribution on the metal plates, so that there is a negative charge surplus on the metal plate shown on the left and a positive charge surplus arises on the metal plate shown on the right. As a result, an electric field is formed between these two charge distributions by the capacitor formed therewith. The molecules with dipole element that flow through this area are aligned accordingly.

3 shows a cross section through an embodiment of a nozzle of a rocket engine according to the invention 1 , It is an engine in the Torus model, in which in the area of the outlet nozzles 15 several chambers are formed by the nozzles. A device for generating an electric field 20 uses the intermediate areas of the individual nozzle chambers, to generate here each negative or positive charge surplus and thus in the chambers of the nozzle 15 create an electric field that aligns the molecules passing through it with the dipole element.

LIST OF REFERENCE NUMBERS

1

Rocket engine

3

Liquid-propellant rocket

5

rocket fuel

8th

Product with a dipole moment

10

combustion chamber

11

flame holder

15

jet

20

Device for generating an electric field

25

metal plate

27

ceramic plate

Claims (4)

A rocket engine (1) for a rocket fuel (5), with a support mass upon combustion of which a product with molecules having a dipole moment (8) is formed, comprising a combustion chamber (10), a nozzle (15), characterized in that a device for generating an electric field (20) is provided laterally, with which at least in an area of the nozzle an electric field is applied, by the transverse and rotational degrees of freedom of the molecular movement of the molecules are limited with dipole moment and the molecules with dipole moment when flying through the electric field ( 20) are rectified. Rocket engine (1) after Claim 1 in which the rocket engine (1) is a liquid rocket engine (3). Rocket engine (1) according to one of the preceding claims, wherein the means for generating an electric field (20) is formed so that also in the region of the combustion chamber (10) an electric field can be applied. Rocket engine (1) according to one of the preceding claims, wherein the means for generating an electric field (20) is formed so that a static homogeneous electric field can be generated.

Images