A hovercraft posture stabilizing device based on magnus effect

Abstract

The application discloses a hovercraft posture stabilizing device based on Magnus effect, which comprises a pipe beam support fixed behind a duct air propeller, a transverse roller assembly and a longitudinal roller assembly which are perpendicular to each other and rotatable are installed on the pipe beam support, the transverse roller assembly comprises left and right rollers which are horizontally installed on the pipe beam support, the longitudinal roller assembly comprises upper and lower rollers which are vertically installed on the pipe beam support, and a motor which drives the left and right rollers and the upper and lower rollers to rotate. When air flow passes through the rollers, a Magnus force which points to the side of the accelerated air flow is generated on the side of the accelerated air flow. When the hovercraft is lowered, the left and right rollers roll clockwise at the same speed, and a downward force is provided to form a counterclockwise pitching moment together with gravity. When the hovercraft is leftwardly deviated, the left and right rollers roll reversely at the same speed, and a rightward rolling moment is provided to restore a good balance state. When the upper and lower rollers rotate at a high speed, the hovercraft is turned.

Description

Technical Field

[0001] This invention relates to a hovercraft stabilization device, specifically a hovercraft attitude stabilization device based on the Magnus effect. Background Technology

[0002] The most significant feature of a fully-cushioned hovercraft is that it uses a flexible skirt installed under the hull to create a high-pressure air cushion, lifting the hull and suspending it above the operating surface. During high-speed cruising in this cushioned state, only the bottom edges of the apron (side and rear) are in contact with the water surface, resulting in low damping and allowing for very high speeds. However, this suspended operation leads to three unique safety risks for hovercraft: "high-speed longitudinal submersion," "low-speed sideslip and capsizing," and "high-speed turning and loss of control due to tail-swing."

[0003] Because the longitudinal stability of a hovercraft is much lower in its cushion state than in its displacement state, a small trim moment can produce a large trim angle. Hovercraft typically use a high-mounted air propeller for propulsion. At high speeds, the trim angle is generally small. However, when encountering a sudden gust of wind in the direction of travel, the propeller thrust increases abruptly, generating a nose-down moment that causes the hull to nose-down. This can cause the bottom of the bow skirt to come into contact with the water surface, changing the force acting on the outer surface of the fingers from aerodynamic to hydrodynamic. Since water is much denser than air (approximately 800 times denser), the force on the fingers increases dramatically, leading to instability and retraction of the bow skirt, a decrease in local air pressure, and a sudden increase in the nose-down angle. In severe cases, this can even cause the rigid structure of the hull to come into contact with the water, a sharp drop in speed, and damage to equipment and personnel.

[0004] The longitudinal stability of existing fully-cushioned hovercraft structures is adjusted using a horizontal tail fin, while lateral stability is ensured using a partition skirt or ballast water technology. Steering is adjusted using a vertical tail fin. For small and lightweight hovercraft, the horizontal and vertical tail fins are generally manually controlled, but this is greatly affected by the incoming current velocity, making it extremely difficult to operate for those unfamiliar with hovercraft operation. Lateral stability partition skirts, which are horizontal or longitudinal partition skirts installed within the perimeter skirt, increase the skirt weight by approximately 1 / 4 to 1 / 3 for hovercraft, thus reducing the effective payload. Ballast water technology, due to its large ballast machinery, is only suitable for large hovercraft. Summary of the Invention

[0005] This invention provides a hovercraft attitude stabilization device based on the Magnus effect to solve the problems of longitudinal stability, lateral stability, steering and heading stability of hovercraft.

[0006] The hovercraft attitude stabilization device based on the Magnus effect of the present invention includes a tube beam support fixed behind the duct air propeller. The tube beam support is equipped with a transverse roller assembly and a longitudinal roller assembly that are perpendicular to each other and rotatable. The transverse roller assembly includes a left roller and a right roller that are horizontally mounted on the tube beam support. The longitudinal roller assembly includes an upper roller and a lower roller that are vertically mounted on the tube beam support. The device also includes a motor that drives the left roller, right roller, upper roller and lower roller to rotate.

[0007] The aforementioned Magnus effect-based hovercraft attitude stabilization device uses mutually perpendicular transverse and longitudinal roller assemblies positioned behind the ducted air propeller. When airflow passes through the rotating rollers, the accelerated side of the airflow generates a Magnus force pointing in the direction of the accelerating airflow. When the hovercraft pitches down, the left and right rollers rotate in the same direction, generating a downward Magnus force that, together with gravity, forms a counterclockwise pitching moment, allowing the hovercraft to return to a pitching or level attitude. When lateral instability occurs due to crosswinds, the left and right rollers rotate in opposite directions at the same speed, generating a rolling moment, allowing the hovercraft to return to a level attitude. When the crosswind is significant, and lateral instability and yaw occur simultaneously, the left and right rollers rotate in opposite directions at the same speed, generating a rolling moment. Simultaneously, the rotation of the upper and lower rollers in the same direction balances the yaw and rolling moments caused by the crosswinds. Furthermore, the high-speed rotation of the upper and lower rollers also enables the hovercraft to steer. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of a hovercraft attitude stabilization device based on the Magnus effect.

[0009] Figure 2 Schematic diagram for adjusting longitudinal attitude.

[0010] Figure 3 Schematic diagram for adjusting lateral attitude.

[0011] Figure 4 Diagram illustrating the principles for adjusting heading stability and achieving steering. Detailed Implementation

[0012] like Figure 1-4As shown, a hovercraft attitude stabilization device based on the Magnus effect includes a tube beam support 2 fixed behind a ducted air propeller 1. The tube beam support is equipped with mutually perpendicular and rotatable transverse roller assembly 3 and longitudinal roller assembly 4. The transverse roller assembly 3 includes a left roller 301 and a right roller 302 horizontally mounted on the tube beam support. The longitudinal roller assembly 4 includes an upper roller 401 and a lower roller 402 vertically mounted on the tube beam support. A motor drives the left, right, upper, and lower rollers to rotate. By arranging mutually perpendicular transverse and longitudinal roller assemblies behind the ducted air propeller, when airflow passes over the rotating rollers, a Magnus force is generated on the accelerated side of the airflow, pointing in the direction of the accelerated airflow. The magnitude of the generated Magnus force is determined by the rotational speed of the rollers, i.e., Magnus force = coefficient * angular velocity * incoming flow velocity * cube of radius * fluid density. When the hovercraft pitches down, the left and right rollers rotate in the same direction, generating a downward Magnus force that, together with gravity, creates a counterclockwise pitching moment, allowing the hovercraft to return to a pitching or level attitude. When the hovercraft becomes laterally unstable due to crosswinds, the left and right rollers rotate in opposite directions at the same speed, generating a rolling moment, allowing the hovercraft to return to a level attitude. When the crosswinds are strong, and lateral instability and yaw occur simultaneously, the left and right rollers rotate in opposite directions at the same speed, generating a rolling moment. Simultaneously, the rotation of the upper and lower rollers in the same direction balances the yaw and rolling moments caused by the crosswinds. Furthermore, the high-speed rotation of the upper and lower rollers also enables the hovercraft to turn.

[0013] The transverse and longitudinal roller assemblies are arranged in a cross shape. A balance ball 5 is located in the middle of the tube beam support 2. A left and right roller, opposite to the duct air propeller, are arranged on both sides of the balance ball in the horizontal direction; an upper and lower roller, opposite to the duct air propeller, are arranged on both sides of the balance ball in the vertical direction. Through the balance ball and the rollers arranged above, below, left, and right of the balance ball, the hovercraft's attitude can be better adjusted according to crosswinds, further improving the hovercraft's attitude stability.

[0014] The left, right, upper, and lower rollers each have a rotating shaft installed inside. The rotating shaft is connected to a motor, and each roller is powered by a motor to rotate independently, thereby generating a Magnus force to balance the yaw moment and roll moment caused by the crosswind.

[0015] The outer sides of the left, right, upper, and lower rollers are wrapped with rubber, which increases the viscosity of the gas flowing over the surface and further improves the stability of the hovercraft's attitude.

[0016] The tube beam support 2 is equipped with a connecting rod 201 that is fixed to the side of the duct 11 of the duct air propeller 1, which can improve the stability of the tube beam support.

[0017] It also includes an attitude control device and tilt sensors installed on both sides of the hovercraft. The tilt sensors are connected to the attitude control device, which is connected to the motor. The attitude of the hovercraft is detected by the tilt sensors, and the motor speed is controlled by the attitude control device to adjust the hovercraft's driving attitude.

Claims

1. A hovercraft attitude stabilization device based on the Magnus effect, characterized in that, The device includes a tube beam support (2) fixed behind the duct air propeller (1), on which a transverse roller assembly (3) and a longitudinal roller assembly (4) are mounted perpendicular to each other and rotatable. The transverse roller assembly (3) includes a left roller (301) and a right roller (302) mounted horizontally on the tube beam support, and the longitudinal roller assembly (4) includes an upper roller (401) and a lower roller (402) mounted vertically on the tube beam support, as well as a motor that drives the left roller, right roller, upper roller and lower roller to rotate.

2. The hovercraft attitude stabilization device based on the Magnus effect according to claim 1, characterized in that, The transverse roller assembly and the longitudinal roller assembly are arranged in a "+" shape. The middle part of the pipe beam support (2) is provided with a balance ball (5). The left and right rollers opposite to the air propeller of the duct are arranged on both sides of the horizontal direction of the balance ball. The upper and lower rollers opposite to the air propeller of the duct are arranged on both sides of the vertical direction of the balance ball.

3. The hovercraft attitude stabilization device based on the Magnus effect according to claim 1, characterized in that, The left roller, right roller, upper roller, and lower roller each have a rotating shaft installed inside, and the rotating shaft is connected to the motor.

4. The hovercraft attitude stabilization device based on the Magnus effect according to claim 1, characterized in that, The outer sides of the left roller, right roller, upper roller, and lower roller are wrapped with rubber.

5. The hovercraft attitude stabilization device based on the Magnus effect according to claim 1, characterized in that, The tube beam support (2) is provided with a connecting rod (201) that is fixed to the side of the duct (11) of the duct air propeller (1).

6. The hovercraft attitude stabilization device based on the Magnus effect according to claim 1, characterized in that, It also includes an attitude control device and tilt sensors installed on both sides of the hovercraft. The tilt sensors are connected to the attitude control device, which is connected to the motor.

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