Intake Grate for Underwater Vehicle Vector-Flow Thruster

This invention was made with government support under N00024-18-C-6300 awarded by United States Navy. The government has certain rights in the invention.

Examples relate to a propulsion system for marine applications and more specifically to an intake grate for a propulsion system that can be used in marine applications.

Often, vehicles for marine applications have a propulsion system that includes an assembly with a motor that powers a propeller. The propeller functions to draw water into the assembly through an intake grate. The water is provided to a nozzle that expels the water as a high-pressure stream. The expulsion of water through the nozzle provides thrust to the vehicle. To maneuver the vehicle, the nozzle can be rotated based on desired direction of motion. However, when the nozzle is rotated, expelled water can be drawn in through the intake grate, thereby reducing thrust created by the water stream.

The following description and the drawings sufficiently illustrate teachings to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some examples may be included in, or substituted for, those of other examples. Teachings set forth in the claims encompass all available equivalents of those claims.

Examples relate to an intake grate for a propulsion system having a propeller and a rotatable vector-flow nozzle. The intake grate can have a plurality of angled intake grate blades extending from a hub of the intake grate towards a rim of the intake grate. Each of the intake grate blades can have a pitch in a first direction. The propeller can include blades and function to draw fluid into the propulsion system via the intake grate. The propeller blades can have a pitch that is opposite to the pitch of the intake grate blades. The propeller blades can have a pitch in a second direction that is opposite to the first direction. The rotatable vector-flow nozzle can function to eject a high-pressure stream of fluid. By virtue of the intake grate blades having a pitch that is opposite a pitch of the propeller, an amount of fluid ejected from the rotatable vector-flow nozzle that can be drawn into the propulsion system by the propeller is minimized.

The pitch angle of the intake grate blades can increase or decrease as the intake grate blades extend from the intake grate hub towards the intake grate rim. A pitch angle can be a twist angle of the blade relative to the horizontal plane normal to the axis of the hub. Thus, a pitch angle of the intake grate blade can a twist angle of the intake grate blade relative to a hub of the intake grate while a pitch angle of the propeller can be a twist angle of the blade relative to a hub of the propeller.

The pitch angle of the intake grate blades at the intake grate hub can vary in comparison to such as being less than an angle of the intake grate blades at the intake grate rim. If the intake grate is symmetrical where the intake grate blades each have the same length, each of the intake grate blades can have the same hub intake grate rim angle and the same intake grate rim angle such that the intake grate rim angle among different intake grate blades does not change and instead remains the same. A length of the intake grate blades can vary based on a shape of the intake grate such that rim intake grate blade angles can vary among groups of the intake grate blades. For example, if the intake grate is asymmetrical, the first group of intake grate blades can have a first length while a second group of intake grate blades can have a second length that is different from the first length. Since the pitch can vary according to length, the first group of intake grate blades can have an intake grate rim angle that is different from an intake grate rim angle of the second group of intake grate blades. Furthermore, the first and second groups of the intake grate blades can have the same hub intake grate angle.

Now referring to, a propulsion systemthat can be used for a vehicle, such as a vehicle having marine applications, is shown. The propulsion systemcan include an intake grateat a fluid intakeof the propulsion system. The intake gratealong with the fluid intakecan be disposed at an endof a housingof the propulsion system.

Fluid F can be drawn into the propulsion systemvia a propellerof the propulsion system. The propellercan be powered by a motorand draw the fluid F into chambersdefined by the propulsion system housing. The propeller motorcan rotate the propellerin either a clockwise or counterclockwise direction. As the propellerrotates, a pressure differential within the propulsion system chamberand an area outside of the propulsion systemis created. The pressure differential can draw the fluid F into the propulsion system chamber.

The propulsion systemcan also have a vector-flow nozzleextending from the propulsion system housingand opposite the fluid intakeat the propulsion system housing. The vector-flow nozzlecan provide thrust for a vehicle that uses the propulsion system. The vector-flow nozzlecan be in fluid communication with the propeller. The vector-flow nozzlecan be coupled to a vector-flow nozzle motorthat can rotate the vector-flow nozzlealong direction Z in a rotatable span of 360 degrees relative to the propulsion system.

The vector-flow nozzlecan provide thrust to a vehicle that uses the propulsion systemin directions throughout the rotatable span of 360 degrees relative to the propulsion system. As the propellerdraws the fluid F into the propulsion system chamber, by virtue of the rotation of the propellerand the propellerbeing in fluid communication with the vector-flow nozzle, the propellercan force the fluid F into the vector-flow nozzle. The vector-flow nozzlecan then eject pressurized thrust fluid TF, which can provide thrust for a vehicle that uses the propulsion system. Since the vector-flow nozzlecan rotate 360 degrees relative to the propulsion system, the vector-flow nozzleis capable of ejecting the thrust fluid TF in a plurality of directions.

As can be seen with reference to, in some configurations, the thrust fluid TP can flow over the intake grate. Moreover, the propellercan be rotating and draw the fluid F into the intake grateand the propulsion system chamber. However, the intake gratecan be configured to minimize the amount of the thrust fluid TP that is drawn into the intake grateand the propulsion system chamber.

Both the intake grateand the propellercan have blades. For example, the intake gratecan include intake grate bladesandwhile the propellercan include a blade. The propeller bladecan define a propeller blade pitchand the intake grate bladesandcan define an intake grate blade pitch. As can be seen with reference to, the propeller blade pitchcan be in a first direction while the intake grate blade pitchcan be in a second direction that is opposite to the first direction. To further illustrate, the propeller blade pitchcan extend in a positive direction along an X-axis while the intake grate blade pitchcan extend in a negative direction along the X-axis.

Returning attention to, the intake gratecan also include an intake grate hubthat is spaced apart from an intake grate rim. The intake grate rimcan be disposed about the intake grate hub, as shown with reference to. The intake grate bladesandcan extend from the intake grate hubtoward and to the intake grate rim. The intake grate bladesandcan be disposed at an intake grate hub anglerelative to the intake grate hub. In examples, the hub intake grate hub anglecan be in a range of about 1° to about 30°.

For purposes of explanation, the propeller blade pitchcan be defined as the propeller bladeextending from a pointalong a Y-axis to a propeller blade pointalong the X-axis. The propeller blade pointcan be along a positive position of the X-axis relative to an intersection of the X-axis with the Y-axis defined by a point. In an example, the pointcan correspond to the intake grate hub. Moreover, the pointcan correspond to an outer point() of the propeller.

The intake grate blade pitchcan be defined as the intake grate bladesandextending from the pointto an intake grate blade pointalong the X-axis. The intake grate blade pointcan be along a negative position of the X-axis relative the point. As can be seen with reference to, the propeller blade pitchand the intake grate blade pitchare opposite to each other.

In addition, each of the intake grate bladesandcan contact the intake grate rimat an intake grate rim angle. The intake grate bladecan contact the intake grate rimat an intake grate rim angle(). Moreover, the intake grate bladecan contact the intake grate rimat an intake grate rim angle().

As discussed above, each of the intake grate bladesandcan have the intake grate blade pitch. The intake grate blade pitchcan correlate to the intake grate hub angleand/or the intake grate rim anglesandwhere the angles,, andcan have a linear relationship with a distance between the pointand the intake grate blade point. Thus, the greater value of the angles,, andthe greater the distance between the pointand the intake grate blade point.

In examples, the intake grate blade pitchcan vary along a length of the intake grate blades where the intake grate blade pitchcan increase as a length of the intake grate blade increases. Thus, the intake grate blade pitchcan have a value at the intake grate hubthat correlates with the intake grate hub angle. In addition, the intake grate blade pitchcan have a value at the intake grate rimthat correlates with the intake grate rim angleor the intake grate rim angle, which can be different from the intake grate hub angle. The intake grate rim angle value can be greater than the intake grate hub angle value, which can correlate to the intake grate rim anglesandbeing greater than the intake grate hub angle.

The intake gratecan have an asymmetrical configuration, such as an oval, where the intake grate bladehas a lengththat is different from a lengthof the intake grate blade. The intake grate blade lengthcan be longer or shorter than the intake grate blade length. In, the intake grate blade lengthis larger than the intake grate blade length. Moreover, the intake gratecan have any standard polygon shape or non-standard polygon shape. Here, since the intake grate blade lengthis larger than the intake grate blade lengthand the intake grate blade pitchcan vary, such as in a linear fashion and here, as a function of a length, the intake grate rim anglecan be larger than the intake grate rim angle. In examples, the intake grate rim angleand the intake grate rim anglecan be in a range between about 30° and about 60°. When the intake grate rim anglediffers from the intake grate rim angle, the intake grate rim anglecan be a first value within the range of about 30° and about 60° while the intake grate rim anglecan be a second value within the range of about 30° and about 60° that is different from the first value.

The intake grate blades can also have a taperthat can complement a shape of the fluid intake. More specifically, in examples where the intake gratehas an asymmetrical configuration and the fluid intakealso has an asymmetrical configuration, the fluid intakecan include a wallhaving an angled configuration that defines a taper. To allow fitment of the intake grateonto the fluid intake, the intake grate blades/can have the intake grate blade taperthat can mirror the fluid intake wall.

As noted above, by virtue of the intake grate blades/having a pitch that is opposite to a pitch of the propeller blade, the intake of the thrust fluid TF by the intake grateis minimized. An amount of intake of the thrust fluid TF by the intake gratecan reduce the amount of thrust provided by the propulsion system. The amount of thrust provided by the propulsion systemcan be characterized as thrust output.

Now referring to, a comparison of thrust output between a propulsion system having an intake grate with blades that pitch in the same direction as blades of a propeller () and thrust output between a propulsion system having an intake grate with blades that pitch in a direction that is opposite to blades of a propeller () is shown.

illustrates examples where intake grate blades and propeller blades have a pitch that is in the same direction. In, the vector-flow nozzlecan have a rotatable spanthat corresponds to a rotation of 360° relative to the propulsion system housing. In, 60° can correspond to a configuration where the vector-flow nozzleejects the thrust fluid TF in a direction that is opposite from an intake grate of a propulsion system. Moreover, 240° can correspond to a configuration where the vector-flow nozzleejects the thrust fluid TF in a direction such that the thrust fluid TF flows over an intake grate of a propulsion system. As can be seen with reference to, in examples where the intake grate blades and propeller blades have a pitch that is in the same direction, thrust generated by a vector-flow nozzle drops of considerably at 240° in comparison to 60°. Moreover, thrust generated by the vector-flow nozzle drops off significantly in a range between 150° and 330°.

illustrates examples where the intake grate blades/have the intake grate blade pitchand the propeller bladehas the propeller blade pitch. Due to the opposing pitches of the intake grate blades/and the propeller blade, thrust generated by the vector-flow nozzlecan vary in a range between about one percent and about ten percent.

In some examples, the intake gratecan have a clocked configuration relative to the propulsion system housing, as shown with reference to. In the examples discussed above, the intake gratecan have a configuration where ones of the intake grate blades, such as the intake grate blades, are in line with a center Z of the propulsion system housing. In further examples, the intake gratealong with the fluid intakecan have a clocked configuration relative to the propulsion system housing. In particular, ones of the intake grate blades of the intake grate, such as the intake grate blades, can be rotated an anglerelative to the propulsion system housing. By clocking the blades with an blade advance or blade retard clocking angle, the in-line blade can be shifted from one side to another side. This can cause an asymmetrical thrust output response when plotting. Additionally, while a singular blade pitch profile are discussed herein, multiple blades profiles for the intake grate blades and/or the propeller blade could be user. Moreover, clocking can optimize drag and thruster efficiency.

Example 1 is a marine propulsion system comprising: a housing; a rotatable vector-flow nozzle extending from the housing and configured to eject a fluid in a plurality of directions; a propeller disposed within the housing and in fluid communication with the rotatable vector-flow nozzle, the propeller having a blade that pitches in a first direction; a fluid intake disposed at an end of the housing and opposite the rotatable vector-flow nozzle; and an intake grate disposed at the fluid intake, the intake grate having an asymmetrical configuration defining a hub and a rim spaced apart and about the hub, the intake grate comprising: a first plurality of intake grate blades wherein: blades of the first plurality of intake grate blades pitch in a second direction that is opposite the first direction; and the blades of the first plurality of intake grate blades have a hub intake grate angle and a first intake grate rim angle; a second plurality of intake grate blades wherein: blades of the second plurality of intake grate blades pitch in the second direction; and the blades of the second plurality of intake grate blades have the hub intake grate angle and a second intake grate rim angle that is different from the first intake grate rim angle.

In Example 2, the subject matter of Example 1 includes, wherein the blades of the first plurality of intake grate blades have a first length and the blades of the second plurality of intake grate blades have a second length that is different from the first length.

In Example 3, the subject matter of Examples 1-2 includes, degrees relative to the housing and the marine propulsion system is configurable to produce thrust via the rotatable vector-flow nozzle that varies in a range between one percent and ten percent throughout the rotatable span.

In Example 4, the subject matter of Examples 1-3 includes, wherein the fluid intake includes a first taper disposed about a periphery of the fluid intake.

In Example 5, the subject matter of Example 4 includes, wherein the blades of the first plurality of intake grate blades have a second taper at a distal end, the second taper mirroring the first taper.

In Example 6, the subject matter of Examples 1-5 includes, wherein the hub intake grate angle is in a range between one degree and thirty degrees.

In Example 7, the subject matter of Example 6 includes, wherein the first intake grate rim angle is in a range between thirty degrees and sixty degrees.

In Example 8, the subject matter of Examples 6-7 includes, wherein the second intake grate rim angle is in a range between thirty degrees and sixty degrees.

In Example 9, the subject matter of Examples 1-8 includes, wherein the intake grate is in a shape of an oval or a polygon.

Example 10 is a marine propulsion system comprising: a housing; a rotatable vector-flow nozzle extending from the housing and configured to eject a fluid in a plurality of directions; a propeller disposed within the housing and in fluid communication with the rotatable vector-flow nozzle, the propeller having a blade that pitches in a first direction; a fluid intake disposed at an end of the housing and opposite the rotatable vector-flow nozzle; and an intake grate disposed at the fluid intake, the intake grate defining a hub and a rim spaced apart and about the hub, the intake grate comprising a plurality of intake grate blades wherein the plurality of intake grate blades: pitch in a second direction that is opposite the first direction; and have a hub intake grate angle at the intake grate hub and a rim intake grate angle at the intake grate rim, the hub intake grate angle being different from the rim intake grate angle.

In Example 11, the subject matter of Example 10 includes, wherein the intake grate has an asymmetrical configuration and the plurality of intake grate blades includes a first plurality of intake grate blades having a first length and a second plurality of intake grate blades having a second length less than the first length.

In Example 12, the subject matter of Example 11 includes, wherein the first plurality of intake grate blades has a first rim intake grate angle and the second plurality of intake grate blades have a second rim intake grate angle that is less than the first rim intake grate angle.

In Example 13, the subject matter of Examples 10-12 includes, degrees relative to the housing and the marine propulsion system is configurable to produce thrust via the rotatable vector-flow nozzle that varies in a range between one percent and ten percent throughout the rotatable span.

In Example 14, the subject matter of Examples 10-13 includes, wherein the hub intake grate angle is in a range between one degree and thirty degrees.

In Example 15, the subject matter of Example 14 includes, wherein the rim intake grate angle is in a range between thirty degrees and sixty degrees.

Example 16 is a marine propulsion system comprising: a housing; a rotatable vector-flow nozzle extending from the housing and configured to eject a fluid in a plurality of directions; a propeller disposed within the housing and in fluid communication with the rotatable vector-flow nozzle, the propeller having a blade that pitches in a first direction; a fluid intake disposed at an end of the housing and opposite the rotatable vector-flow nozzle; and an intake grate disposed at the fluid intake, the intake grate defining a hub and a rim spaced apart and about the hub, the intake grate comprising a plurality of intake grate blades, wherein the plurality of intake grate blades pitch in a second direction that is opposite the first direction.

In Example 17, the subject matter of Example 16 includes, wherein the plurality of intake grate blades have a hub intake grate angle at the intake grate hub and a rim intake grate angle at the intake grate rim, the hub intake grate angle being less than the rim intake grate angle.

In Example 18, the subject matter of Examples 16-17 includes, degrees relative to the housing and the marine propulsion system is configurable to produce thrust via the rotatable vector-flow nozzle that varies in a range between one percent and ten percent throughout the rotatable span.

In Example 19, the subject matter of Examples 16-18 includes, wherein the intake grate has an asymmetrical configuration and the plurality of intake grate blades includes a first plurality of intake grate blades having a first length and a second plurality of intake grate blades having a second length less than the first length.

In Example 20, the subject matter of Example 19 includes, wherein the first plurality of intake grate blades has a first rim intake grate angle and the second plurality of intake grate blades have a second rim intake grate angle that is less than the first rim intake grate angle.

Example 21 is an apparatus comprising means to implement of any of Examples 1-20.

Example 23 is a system to implement of any of Examples 1-20.

Example 24 is a method to implement of any of Examples 1-20.

Although teachings have been described with reference to specific example teachings, it will be evident that various modifications and changes may be made to these teachings without departing from the broader spirit and scope of the teachings. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. The accompanying drawings that form a part hereof, show by way of illustration, and not of limitation, specific teachings in which the subject matter may be practiced. The teachings illustrated are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other teachings may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various teachings is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.