JP2685114B2 - Rocket engine injectors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can maintain a high combustion efficiency even in an injector in a rocket engine using liquid oxygen and hydrogen or liquid oxygen and methane as a propellant, particularly in a widely varying mixing ratio. Structural rocket engine injectors.

[0002]

2. Description of the Related Art A conventional liquid oxygen / hydrogen rocket engine or a liquid oxygen / methane rocket engine comprises an injector 21 and a combustor 22 as shown in FIG. The combustor 22 has a cooling groove 23, and the combustor is cooled by liquid hydrogen or liquid methane that is a liquid fuel. By flowing these liquid fuels from the inlet manifold 24 into the cooling groove 23, Cool the combustor 22. The cooled liquid fuel 26 is gasified, becomes a gas fuel 27, and is supplied to the injector 21 via the outlet manifold 25. Therefore, in these rocket engines, liquid fuel of hydrogen or methane is injected into the combustor in a gaseous state (hereinafter, gas hydrogen and gas methane are referred to as gas fuel). The gas fuel supplied to the injector is liquid oxygen 28
At the same time, it is sent to the combustor 22 and burned.

The injector for a rocket engine using hydrogen / methane as a fuel has a liquid propellant injection part 29 for injecting liquid oxygen in the center as shown in the figure, and a gas propellant injection part 30 for injecting gas fuel. Are arranged so as to enclose the liquid oxygen injected from the liquid propellant injection unit, and have a coaxial structure. In addition, in this figure, the injector is represented by a set of elements (hereinafter referred to as a single element) each including one gas propellant injection section 30 of gas fuel and one liquid propellant injection section 29. The actual injector consists of several single elements.

In order to improve the combustion efficiency of a rocket engine, it is necessary to make liquid oxygen, which is a liquid, into particles as small as possible (atomization) at a position as close to the injector as possible. Conventionally, liquid oxygen is atomized by gas fuel. It is structured to However, since the gas propellant injection unit that injects the gas fuel in the conventional injector injects the gas fuel parallel to the injection direction of liquid oxygen, in a region where the mixing ratio (ratio of oxidant and fuel) is high, Since the amount of gas fuel to be atomized is small, the velocity energy for promoting atomization is small, and the particle size of liquid oxygen is large. Therefore, when the mixing ratio is changed over a wide range, it is difficult to obtain highly efficient combustion especially at a high mixing ratio, and there is a problem that highly efficient combustion can be obtained only in a narrow mixing ratio. Another method to increase the combustion efficiency is to increase the volume of the combustor, but the rocket combustor is required to be light in weight and small in volume, so it is not easy to increase the size of the combustor. There is a problem that can not be done.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and solves the above-mentioned problems of the conventional rocket engine injectors, and can be applied to a wide range without increasing the volume of the combustor. It is an object of the present invention to obtain a rocket engine injector that can maintain highly efficient combustion even with a changing mixing ratio.

[0006]

DISCLOSURE OF THE INVENTION As a result of repeated research to solve the above problems, the present inventors have found that a coaxial injector has a structure in which the inside of an outlet for gas fuel is contracted. The present inventors have found that the atomization performance of oxygen and the gas-liquid mixing performance can be significantly improved, and have reached the present invention. That is, the injector of the rocket engine of the present invention is a rocket engine injector in which the propellant injected from the injector is a liquid propellant and a gas propellant, and the single element of the injector is has a liquid propellant injector for injecting liquid propellant from the central portion, and a gas propellant injector for injecting a gas propellant to wrap the liquid propellant is injected from the liquid propellant injector, promoting Connect to the agent injection port
The inside of the outlet of the gas propellant injection part is formed into a tapered shape that contracts on the axis of the liquid propellant injection part, and the gas propellant injected from the gas propellant injection part is injected into the liquid propellant inside the injector. The above-mentioned problems have been solved by a configuration characterized in that the liquid propellant is made to atomize by colliding with the liquid propellant injected from the injection unit.

The injector of the rocket engine of the present invention uses a rocket engine in which the propellant injected from the injector is a liquid oxidizer and a gas fuel, and similarly, a propellant is a liquid fuel and a gas oxidizer. It can be applied to rocket engines that use various propellants, such as rocket engines, rocket engines that use liquid fuel and gas fuel with different physical properties, and liquid oxidizer as propellants. Further, the present invention can be applied to a rocket engine injector having one or a plurality of single elements consisting of a pair of a liquid propellant injection section and a gas propellant injection section. , It is desirable that all have the configuration according to claim 1 of the claims,
The degree of contraction inside the outlet of the gas propellant injection part of each single element is not necessarily the same, and optimum conditions are set by each part, and in some cases it is possible to combine single elements that do not have a contraction structure. Is.

In the case of a rocket engine injector in which the fuel injected from the injector is a liquid fuel and a gas fuel having different physical properties, and a liquid oxidizer as a propellant, one single element of the injector is used. Has a liquid propellant injection section for injecting liquid fuel from the central portion, and a gas propellant injection section for injecting gas fuel so as to wrap the liquid fuel injected from the liquid propellant injection section, One element has a liquid propellant injection part for injecting a liquid oxidizer from the central part, and a gas propellant injection part for injecting gas fuel so as to wrap the liquid oxidizer injected from the liquid propellant injection part. The problem is solved by forming the outlet inside of the gas propellant injection portion of at least one of the single elements into a tapered shape that contracts in the liquid propellant injection direction.

As the gas fuel in the above structure, vaporized gas of the fuel that has cooled the rocket nozzle and the rocket combustor or the fuel rich combustion gas of the high temperature gas generator can be used, and as the gas oxidant, the rocket nozzle and the rocket combustor. It is possible to use vaporized gas of the oxidant that has been cooled, or combustion gas rich in the oxidant of the high temperature gas generator. Further, the combustion gas of the high temperature gas generator can be used as the gas propellant injected from the gas propellant injection unit.

[0010]

[Function] By making the inside of the outlet of the gas propellant injection unit have a contracted structure, the gas propellant injected by the gas propellant injection unit collides with the liquid propellant injected by the liquid propellant injection unit, and the gas propellant is injected. The propellant penetrates into the liquid propellant to form bubbles. The gas propellant in the form of bubbles is injected from the injector to the combustor together with the liquid propellant. Since the pressure inside the combustor is lower than the pressure inside the injector, the gas propellant expands,
Liquid propellant is atomized into smaller particles during the expansion process. Therefore, the liquid propellant is atomized and has a shorter period of time for combustion than the liquid oxidizer having a large particle size, and the oxidizer and the fuel are directly mixed, so that the mixing performance is remarkably improved to improve the combustion efficiency. Can be dramatically increased, and a highly efficient combustor with a small combustor volume can be obtained. Further, since the gas-liquid mixed jet by the rocket injector of the present invention increases the compressibility of the propellant, theoretically the dynamic capacitance of the propellant injection can be increased, which is extremely advantageous in terms of combustion stability. is there.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a main part of a rocket engine including an injector according to an embodiment of the present invention, and FIG. 2 shows an enlarged main part of the injector. In this example, an injector in a rocket engine using gas fuel and liquid oxygen as a propellant will be described. In the figure, 1 is an injector, 2 is a combustor, which is a coaxial rocket injector similar to the injector of a conventional rocket engine. Reference numeral 3 is a gas propellant supply pipe for supplying a gas fuel functioning as atomized gas, and like the one shown in FIG. 5, a gas fuel such as hydrogen or methane gasified by cooling the combustor is passed through a manifold. Supplied into the injector. A liquid propellant supply pipe 4 supplies a liquid propellant such as liquid oxygen to the injector. Reference numeral 11 is a gas propellant injection part for injecting the gas fuel supplied to the injector 1, and as shown in the drawing, the inside of the outlet connected to the propellant injection port 5 contracts on the axis of the liquid propellant injection part 12. It has a squeezing structure,
Change the injection direction to the central part where liquid oxygen is injected,
It is designed to contract and eject.

FIG. 2 is an enlarged view showing details of the contraction structure. In the figure, da is the liquid propellant injection part diameter, db is the propellant injection part diameter, xa is the liquid propellant injection nozzle retreat distance, xb is the parallel part distance,
xc is the thickness of the liquid propellant injection part, xd is the contraction part distance, θa is the auxiliary contraction angle, and θb is the contraction angle, which are the main dimensions of the part of the injector where the gas and liquid come into contact. These dimensions are
Various design changes can be made according to the conditions, but the dimensions are set to optimize atomization of the liquid propellant and mixing of the liquid propellant and the gas propellant. For example, if the propellant injection portion diameter db for injecting the gas propellant is set to be a value as small as possible with respect to the liquid propellant injection portion diameter da, the gas injection speed is increased and atomization is improved. However, in that case, a higher pressure is required to eject the gas or liquid. Further, by adjusting the auxiliary contraction angle θa and the contraction angle θb, the angle at which the gas propellant collides with the liquid propellant can be adjusted, and the degree of atomization of the liquid propellant also varies accordingly.

The rocket injector of the present invention is constructed as described above, and the liquid fuel 8 injected by the liquid propellant injection unit 12 is supplied with the gas fuel 7 injected by the gas fuel injection unit 11 having a contracting structure. Upon collision, the gas fuel penetrates into the liquid oxygen to form bubbles 13. The gas fuel in the form of bubbles is injected from the injector 1 to the combustor 2 together with liquid oxygen. Since the pressure inside the combustor is lower than the pressure inside the injector, the gas fuel expands and atomizes liquid oxygen into smaller particles during the expansion process. Moreover, since the oxidizer and the fuel are directly mixed, the mixing performance is remarkably improved, the combustion efficiency is dramatically increased compared to the conventional rocket engine, and a small-volume, high-efficiency combustor is realized. You can

As described above, in the above embodiment, the liquid oxygen / gas fuel having a structure in which the gas fuel injected from the periphery into the liquid oxygen (liquid oxidizer) injected from the central portion enters inside the liquid oxygen is the propellant. The rocket injector according to the present invention has been described above, but the rocket injector according to the present invention is not limited to the above-described embodiment, and can be applied to rocket engine injectors using other propellants. Hereinafter, the embodiment will be described.
When this injector is applied to a liquid oxygen / kerosene rocket engine whose propellant is liquid oxygen / kerosene, kerosene, which is a liquid fuel, is injected from the central part to cool the combustor and gasify the gas oxygen (gas oxidizer ), The atomization of kerosene can be promoted, and a highly efficient injector for a liquid oxygen kerosene engine can be obtained.

In a rocket engine injector using two types of fuels having different physical properties (for example, hydrogen and kerosene or methane and kerosene) and liquid oxygen as a propellant,
It can also be applied to rocket injectors that atomize kerosene with fuel that is easily gasified. An example in that case is shown in FIGS. The injector 15 of this embodiment has a large number of single elements, and the structure of each single element is the same as that of the above-mentioned embodiment, so the same reference numerals are used and detailed description is omitted. Regarding _one single element a ₁ (the propellant injection port is indicated by a black circle in FIG. 4), kerosene, which is a liquid fuel, is injected from the central part, and gas fuel (gas hydrogen) is injected from the peripheral part. Or gas methane) is injected to atomize the liquid fuel with the gas fuel. The other single element a
₂ (The propellant injection port is shown as a white circle in Fig. 4)
Then, a liquid oxidizer (liquid oxygen) is injected from the central part, and gas fuel is injected from the peripheral part so as to wrap it, and the liquid oxidizer is atomized by the gas fuel. With such a configuration, it is possible to obtain a rocket engine having two types of fuels having different physical properties and excellent propellant properties and liquid oxygen, which have excellent combustion efficiency.

[0016]

The present invention has the following special effects. According to the injector of the rocket engine of the present invention, the gas propellant may be collided with the liquid propellant to further promote atomization of the liquid propellant by the gas propellant, and the liquid propellant and the gas propellant. Since and are directly mixed, the mixing performance can be significantly improved, and highly efficient combustion can be obtained even in a region where the ratio of the liquid propellant injection flow rate to the gas propellant injection flow rate is high. By comparison, combustion efficiency can be dramatically improved. Therefore, according to the present invention, the combustion efficiency can be improved without increasing the volume of the combustor, and a highly efficient combustor having a small combustor volume can be obtained. Furthermore, the mixed jet of gas and liquid by the injector of the present invention increases the compressibility of the propellant, and thus can increase the dynamic capacitance of the propellant injection, which is extremely advantageous in terms of combustion stability.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a rocket engine to which an injector according to an embodiment of the present invention is applied.

FIG. 2 is a cross-sectional view of essential parts of an injector according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of essential parts of a rocket engine to which an injector according to another embodiment of the present invention is applied.

FIG. 4 is a side view of the injector seen from the combustion chamber side in the rocket engine of FIG.

FIG. 5 is a conceptual cross-sectional view of a conventional liquid oxygen / hydrogen and liquid oxygen / methane rocket engine.

[Explanation of symbols]

1, 15 Injector 2, 16 Combustor 3 Gas propellant supply pipe 4 Liquid propellant supply pipe 5 Propellant injection port 11 Gas propellant injection part 12 Liquid propellant injection part 13 Bubbles

Continuation of the front page (56) Bibliographic references Sho 63-126546 (JP, U) US Patent 3446024 (US, A) US Patent 3408816 (US, A)

Claims (14)

(57) [Claims] 1. A propellant injected from an injector is a rocket engine injector having a liquid propellant and a gas propellant as a propellant, and a single element of the injector is a liquid propellant from a central portion. And a gas propellant injection unit for injecting a gas propellant so as to wrap the liquid propellant injected from the liquid propellant injection unit, and the liquid propellant injection unit is connected to the propellant injection port.
The inside of the outlet of the gas propellant injection part is formed into a tapered shape that contracts on the axis of the liquid propellant injection part, and the gas propellant injected from the gas propellant injection part is injected into the liquid propellant inside the injector. An injector for a rocket engine, characterized by colliding with a liquid propellant injected from an injection unit to atomize the liquid propellant. 2. The rocket engine according to claim 1, wherein the liquid propellant injected from the liquid propellant injection unit is a liquid oxidizer, and the gas propellant injected from the gas propellant injection unit is a gas fuel. Injector. 3. The rocket engine injection according to claim 1, wherein the liquid propellant injected from the liquid propellant injection unit is a liquid fuel, and the gas propellant injected from the gas injection unit is a gas oxidizer. vessel. 4. The method according to claim 1, wherein the single element is one.
Alternatively, the injector of the rocket engine according to item 3. 5. The method according to claim 1, comprising a plurality of the single elements.
The rocket engine injector according to 2 or 3. 6. The injector for a rocket engine according to claim 3, 4 or 5, wherein the gas oxidant is a vaporized gas of the oxidant that cools the rocket nozzle and the rocket combustor. 7. The injector of a rocket engine according to claim 3, 4 or 5, wherein the gas oxidant is an oxidant rich combustion gas of a high temperature gas generator. 8. An injector for a rocket engine in which the fuel injected from the injector is a liquid fuel and a gas fuel having different physical properties and a liquid oxidizer as a propellant, and one single element of the injector. Has a liquid propellant injection section for injecting liquid fuel from the central portion, and a gas propellant injection section for injecting gas fuel so as to wrap the liquid fuel injected from the liquid propellant injection section, One element has a liquid propellant injection part for injecting a liquid oxidizer from the central part, and a gas propellant injection part for injecting gas fuel so as to wrap the liquid oxidizer injected from the liquid propellant injection part. , The inside of the outlet of the gas propellant injection part of at least one of the single elements is formed in a tapered shape that contracts in the liquid propellant injection direction, and the gas propellant injected from the gas injection part is the liquid propellant. Do not collide with the liquid propellant sprayed from the spray unit. An injector of a rocket engine, characterized in that the liquid propellant is atomized. 9. The injector of a rocket engine according to claim 8, wherein the insides of the outlets of the gas propellant injection portions of both of the single elements are formed in a tapered shape that contracts in the liquid propellant injection direction. 10. A combination of both single elements as a set.
Alternatively, the injector of the rocket engine according to item 9. 11. An injector for a rocket engine according to claim 8 or 9, having a plurality of sets of both single elements. 12. The rocket engine injector according to claim 2, wherein the gas fuel is a vaporized gas of fuel for cooling a rocket nozzle and a rocket combustor. 13. The gas propellant injected from the gas propellant injection part is a combustion gas of a high temperature gas generator, according to claim 1. A rocket engine injector. 14. The gas fuel is a fuel rich combustion gas of a high temperature gas generator, 2, 4, 5, 8, 9, 10.
Alternatively, the injector of the rocket engine according to item 11.