Patent Description:
The subject matter described herein relates to a vortex thruster system that can generate various thrust levels.

Design requirements for a rocket combustion engine can include competing or conflicting requirements. For example, an efficient rocket combustion chamber can thoroughly mix fuel and oxidizer to generate complete combustion. However, complete combustion can cause intense thermal stress of the rocket engine hardware. A cooling mechanism may be required to prevent overheating, but conventional cooling mechanisms can add weight to a system that is mass-sensitive.

Some rocket engines can achieve high mixing rates and combustion efficiencies through the use of complex propellant injectors that can be heavy and expensive to manufacture. Furthermore, some rocket engines include intricate regenerative coolant channels to remove heat from the rocket hardware. Such rocket engine configurations may be difficult and expensive to manufacture, as well as require an increase in overall size and weight of the rocket engine.

<NPL> discloses a vortex thruster system having a catalyst bed, a first valve and a vortex combustion chamber.

Aspects of the current subject matter include various embodiments of a vortex thruster system that can generate various thrust levels. In one aspect, the vortex thruster system includes the features of claim <NUM>.

In some variations one or more of the following features can optionally be included in any feasible combination. In some embodiments, the vortex thruster system can include a second valve for controlling a second flow rate of the monopropellant into the catalyst bed. The second flow rate can be greater than the first flow rate. The delivery of the monopropellant at the second flow rate can generate a second thrust level that is greater than the first thrust level.

In some embodiments, the vortex thruster system can include a secondary propellant valve configured to deliver a secondary propellant into the vortex combustion chamber including the decomposed monopropellant to create a third thrust level that is greater than the second thrust level.

In some embodiments, the monopropellant can include hydrogen peroxide or hydrazine. The decomposed monopropellant can include water vapor and oxygen. The decomposed monopropellant can include nitrogen, hydrogen, and ammonia. The secondary propellant can include a kerosene or a mixed oxide of nitrogen.

In another interrelated aspect of the current subject matter, a method includes the steps of claim <NUM>.

In some embodiments, the delivering of the decomposed monopropellant into the vortex combustion chamber can include delivering a first amount of the decomposed monopropellant through a first injection port positioned proximate a sidewall of the vortex combustion chamber and configured to deliver the first amount of the decomposed monopropellant in a direction tangent to the sidewall. In some embodiments, the delivering of the decomposed monopropellant into the vortex combustion chamber can include delivering a second amount of the decomposed monopropellant through a second injection port positioned proximate to a proximal end of the vortex combustion chamber and configured to deliver the second amount of the decomposed monopropellant into a center area of the vortex combustion chamber.

In some embodiments, the method can further include activating a second monopropellant valve to deliver the monopropellant at a second flow rate to the catalyst bed. The second flow rate can be greater than the first flow rate. The delivery of the monopropellant at the second flow rate can create a second thrust level that is greater than the first thrust level.

In some embodiments, the method can further include activating a secondary propellant valve to deliver a secondary propellant into the vortex combustion chamber including the decomposed monopropellant to create a third thrust level that is greater than the second thrust level. The monopropellant can include hydrogen peroxide or hydrazine. The secondary propellant can include kerosene or a mixed oxide of nitrogen.

Various embodiments of a vortex thruster system are described herein that can be included in various propulsion systems and can provide an efficient and effective way to generate various thrust levels. For example, the vortex thruster system can be configured to efficiently generate at least three discrete thrust levels, such as a high thrust level, a medium thrust level, and a low thrust level. Additionally, the vortex thruster system can be configured to generate a swirling or vortex flow field in a combustion chamber to limit thermal loading of the hardware of the vortex thruster system. Various vortex thruster system embodiments are described in greater detail below.

In some embodiments, the vortex thruster system can include a catalyst bed and at least one oxidizer or monopropellant injector configured to deliver a monopropellant into the catalyst bed. The catalyst bed can be configured to decompose the monopropellant, such as decompose hydrogen peroxide into high-temperature water vapor and gaseous oxygen. The catalyst bed can be in communication with a vortex combustion chamber such that the decomposed monopropellant formed in the catalyst bed can be delivered into the vortex combustion chamber. Delivery of the decomposed monopropellant into the vortex combustion chamber can generate thrust by exhausting the products of decomposition through a nozzle extending from the vortex combustion chamber.

In some embodiments, the vortex thruster system can control a flow rate at which the monopropellant is delivered to the catalyst bed, which can affect the amount of thrust generated at the nozzle. For example, the vortex thruster system can include a first monopropellant valve and a second monopropellant valve that are each configured to deliver the monopropellant at a different flow rate (e.g., a greater flow rate of the monopropellant into the catalyst bed can result in a greater generated thrust). In some embodiments, the vortex thruster system can include a secondary propellant valve that directly injects a secondary propellant (e.g., a kerosene) into the vortex combustion chamber to ignite with the decomposed monopropellant in a bi-propellant configuration to generate a highest thrust level that can be achieved by the vortex thruster system.

Furthermore, in some embodiments the vortex combustion chamber can include at least one tangential injection port, such as at least an array of tangential injection ports, that are configured to deliver the decomposed monopropellant in a direction tangential to a circumference of an inner cylindrical surface of the vortex combustion chamber. This tangential injection can cause a flow of the decomposed monopropellant to swirl in the vortex combustion chamber. The swirl flow may translate upwards towards the proximal end of the vortex combustion chamber where the flow can turn inward and move spirally away from a closed proximal end of the vortex combustion chamber, down the center of the vortex combustion chamber, and out the nozzle.

The vortex thruster system includes at least one axial proximal injection port for delivering a portion of the decomposed monopropellant into a center area of the vortex combustion chamber. This may assist with efficiently and effectively optimizing the vortex combustion chamber for achieving a desired thrust level while simultaneously limiting the thermal load on the thruster hardware. As described herein, a thrust level can include an approximate range of thrust loads, such as a low thrust level including a first thrust load range (e.g., approximately 89N to 135N (<NUM> lbf to <NUM> lbf)), a medium thrust level including a second thrust load range (e.g., approximately 222N to 266N (<NUM> lbf to <NUM> lbf)), and a high thrust level including a third thrust load range (e.g., approximately 445N to 534N (<NUM> lbf to <NUM> lbf)). Other thrust levels and thrust load ranges are within the scope of this disclosure.

<FIG> illustrate an embodiment of a vortex thruster system <NUM> configured to efficiently and effectively generate at least three discrete thrust levels. As shown in <FIG>, the vortex thruster system <NUM> can include a vortex combustion chamber <NUM> having a proximal end <NUM>, a distal end <NUM>, and a sidewall <NUM> extending between the proximal end <NUM> and distal end <NUM>. The vortex combustion chamber <NUM> may be cylindrical in shape, as shown in <FIG>, however, other shapes are within the scope of this disclosure. For example, the proximal end <NUM> of the vortex combustion chamber may include a hollow dome-shape and the distal end <NUM> may include a converging-diverging nozzle <NUM> that provides a passageway through the distal end <NUM> of the vortex combustion chamber <NUM>, as shown in <FIG>.

As shown in <FIG>, the vortex thruster system <NUM> may include a catalyst bed <NUM> and at least one monopropellant valve, such as a first monopropellant valve <NUM> and a second monopropellant valve <NUM>, in communication with the catalyst bed <NUM>. In some embodiments, the first monopropellant valve <NUM> is configured to provide a different flow rate of monopropellant <NUM> into the catalyst bed <NUM> compared to the second monopropellant valve <NUM>. For example, the first monopropellant valve <NUM> can provide a lower flow rate of monopropellant to allow the vortex thruster system <NUM> to generate a first, lower thrust level. Additionally, the second monopropellant valve <NUM> can provide a higher flow rate of monopropellant to allow the vortex thruster system <NUM> to generate a higher, second thrust level that is greater than the first, lower thrust load.

The catalyst bed <NUM> can be configured to decompose the monopropellant <NUM> as it flows axially through the catalyst bed <NUM>. The decomposed monopropellant <NUM> can then be delivered into the vortex combustion chamber <NUM> to assist with generating thrust, as will be described in greater detail below. In some embodiments, the monopropellant <NUM> can include a liquid hydrogen peroxide (e.g., <NUM>% hydrogen peroxide) and the decomposed monopropellant <NUM> can include water vapor and gaseous oxygen. Other monopropellants (e.g. hydrazine) are within the scope of this disclosure. In some embodiments, the catalyst bed <NUM> can include a stack of reactive and inert metallic screens. Other catalyst beds that can decompose monopropellants (e.g. iridium-coated alumina pellet beds) are within the scope of this disclosure.

As shown in <FIG> and <FIG>, some embodiments of the vortex thruster system <NUM> can include an annular chamber <NUM> positioned around at least a part of the vortex combustion chamber <NUM> and in fluid communication with an outlet of the catalyst bed <NUM>. The annular chamber <NUM> can allow the decomposed monopropellant <NUM> to enter the vortex combustion chamber by passing through at least one array of tangential injection ports <NUM> positioned along the sidewall <NUM> of the vortex combustion chamber <NUM>, as shown in <FIG>. The vortex thruster system <NUM> can include a proximal chamber <NUM> for allowing the decomposed monopropellant <NUM> to be injected into a proximal end of the vortex combustion chamber <NUM> through at least one proximal injection port <NUM>, as also shown in <FIG>. Any number of chambers and injectors can be included in the vortex thruster system <NUM> for directing and controlling the delivery of the decomposed monopropellant <NUM> into the vortex combustion chamber <NUM>.

As shown in <FIG> and <FIG>, at least one array of tangential injection ports <NUM> may be positioned along the sidewall <NUM> of the vortex combustion chamber and configured to direct the decomposed monopropellant <NUM> at a direction that is tangential to the circumference of the inner cylindrical surface of the sidewall <NUM> of the vortex combustion chamber <NUM>. This creates a swirling or vortex flow field of the decomposed monopropellant <NUM> along an outer circumference of the vortex combustion chamber <NUM>. Such swirling can improve combustion efficiency and control hardware temperatures by shielding the vortex combustion chamber walls from high-temperature products of combustion.

As shown in <FIG> and <FIG>, at least one proximal injection port <NUM> may be axially positioned along the proximal end <NUM> of the vortex combustion chamber <NUM>. For example, the proximal injection port <NUM> may be positioned approximately parallel to or along a longitudinal axis of the vortex combustion chamber <NUM>. The proximal injection port <NUM> may be configured to deliver a portion of the decomposed monopropellant <NUM> into a combustion zone at or near the centerline of the vortex combustion chamber <NUM> (e.g., along a longitudinal axis of the vortex combustion chamber). The proximal injection port <NUM> may provide a trim function that can balance mixing and cooling functions of the vortex flow field.

As shown in <FIG>, some embodiments of the vortex thruster system <NUM> can include a secondary propellant valve <NUM> configured to directly inject a secondary propellant (e.g., kerosene, such as RP-<NUM> kerosene) directly into the vortex combustion chamber <NUM>. Other secondary propellants (e.g., mixed oxides of nitrogen (MON)) are within the scope of this disclosure. As shown in <FIG>, the secondary propellant can be delivered to a proximal end of the vortex combustion chamber. The secondary propellant can mix with high-temperature products of the decomposed monopropellant in the vortex combustion chamber to generate a desired thrust level (e.g., a high thrust mode).

As discussed above, the vortex thruster system <NUM> can be configured to generate at least three different thrust levels that each generate discrete thrust loads or load ranges. For example, the vortex thruster system <NUM> can generate a low thrust level (e.g., generates approximately 107N (<NUM> lbf)), a medium thrust level (e.g., generates approximately 245N (<NUM> lbf)), and a high thrust level (e.g., generates approximately 490N (<NUM> lbf)). For example, the low thrust level can be achieved by activating the first monopropellant valve <NUM> thereby delivering the monopropellant at a first, lower flow rate into the catalyst bed <NUM>. Additionally, the medium thrust level can be achieved by activating the second monopropellant valve <NUM> thereby delivering the monopropellant at a second, greater flow rate into the catalyst bed <NUM>. Furthermore, the high thrust level can be achieved by activating the second monopropellant valve <NUM> as well as the secondary propellant valve <NUM> to allow the secondary propellant to mix and ignite with the decomposed monopropellant <NUM> in the vortex combustion chamber <NUM>.

For example, during operation of the vortex thruster system <NUM> to achieve a low, medium, or high thrust level, liquid hydrogen peroxide can be injected into the catalyst bed <NUM> where the liquid hydrogen peroxide exothermically decomposes into gaseous oxygen and water vapor as it flows axially through the catalyst bed <NUM>. Additionally, upon exiting the catalyst bed <NUM>, the decomposed monopropellant <NUM> can be approximately 760C (<NUM>,<NUM> degrees F) and can flow into the annular chamber <NUM> and/or proximal chamber <NUM> surrounding the vortex combustion chamber <NUM>. The hot oxidizing gas (e.g., the decomposed monopropellant <NUM>) can then enter the vortex combustion chamber <NUM> through the array of tangential injection ports <NUM> and/or the proximal injection port <NUM>. The result of the decomposed monopropellant in the vortex combustion chamber can result in the flow of hot gas through the nozzle <NUM> (e.g., niobium nozzle) and the generation of monopropellant thrust (e.g., low or medium thrust levels).

Furthermore, to generate the high thrust level, a secondary propellant (e.g., kerosene) can be added to vortex combustion chamber <NUM> to allow mixing and burning of the secondary monopropellant and decomposed monopropellant in the vortex combustion chamber <NUM>. The products of such mixing and burning can result in combustion flow through the nozzle <NUM> (e.g., niobium nozzle) and generation of bipropellant thrust. In some embodiments, the nozzle <NUM> may be coated with a silicide coating that can protect against oxidation of the niobium. Other features, functions and benefits of the vortex thruster system <NUM> are within the scope of this disclosure.

Claim 1:
A vortex thruster system (<NUM>), comprising:
a catalyst bed (<NUM>) configured to decompose a monopropellant delivered to the catalyst bed;
a first valve (<NUM>) for controlling delivery of the monopropellant at a first flow rate into the catalyst bed to transform the monopropellant into a decomposed monopropellant; and
a vortex combustion chamber (<NUM>) in fluid communication with the catalyst bed and configured to receive the decomposed monopropellant from the catalyst bed, the decomposed monopropellant assisting with creating a first thrust level,
the system being characterised in that the vortex combustion chamber (<NUM>) includes at least one side injection port (<NUM>) positioned proximate to a sidewall (<NUM>) of the vortex combustion chamber and configured to deliver a first amount of the decomposed monopropellant into the vortex combustion chamber in a direction that is approximately tangent to the sidewall, and
and in that the vortex combustion chamber (<NUM>) includes a proximal injection port (<NUM>) positioned proximate to a proximal end of the vortex combustion chamber and configured to deliver a second amount of the decomposed monopropellant into a center area of the vortex combustion chamber.