JPH03281471A - Hovercraft - Google Patents

Abstract

PURPOSE:To obtain a turnable hovercraft which an extremely small slip angle by providing an aerodynamic lateral force generating device having an air cushion part in the bottom section of an aircraft body and a member planted on the top part of the middle section of the aircraft body and extending longitudinally of the aircraft body. CONSTITUTION:There is provided an aerodynamic lateral force generating device 6 having an air cushion part 2 in the bottom section of an aircraft body 1, and a member planted on the top part of the middle section of the aircraft body 1 and extending substantially in a longitudinal direction thereof. When this hovercraft turns with a small lateral slip angle beta under a thrust T, this slip angle beta gives an angle of attack to vertical stabilizers 6 with respect to a wind stream having a velocity V, and accordingly, an aerodynamic force is applied to the vertical stabilizers 6. This aerodynamic force can be divided into a lateral force L directed to the center of the turn, and a drag D, the lateral force L balancing with the centrifugal force of the aircraft body. Further, the aerodynamic force can obtain the lateral force L which is larger than the drag D, and accordingly, the slip angle beta can be made to be small and further, the thrust force T can be also made to be small since the drag D is small.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a hovercraft.

[Conventional technology]

For example, a hovercraft floats by forming an air cushion layer between it and the water surface or the ground at its skirt portion, and travels in a floating state by the thrust of a propulsion device. Therefore, the above-mentioned thrust force and air resistance during traveling mainly act on the aircraft body.

[Problem to be solved by the invention]

Such a conventional hovercraft must travel under a large sideslip angle β when turning, as shown in FIG. That is, when turning around a circle with the center 0 as the trajectory P, if the mass of the aircraft is m and the traveling speed is V (in the figure, the wind speed relative to the aircraft is shown as ■), then IIV A large centrifugal force of ``/R'' acts on the aircraft body.The centripetal force that balances the centrifugal force of the value of ``/R'' is Tsin β, where T is the propulsive force.

Obtained as a component in the direction. Therefore, in order for this to become a value that balances the centrifugal force, either β should be increased or T
must be made larger. In the former case, the aircraft moves forward largely sideways, which is unfavorable for maneuverability and makes the ride extremely uncomfortable; in the latter case, it is disadvantageous in terms of energy-saving effects. This brings about the problem.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the conventional hovercraft and to provide a hovercraft that can turn with an extremely small sideslip angle.

[Means to solve the problem]

According to the present invention, the above-mentioned object is an aerodynamic lateral force generating device comprising an air cushion section at the bottom of the fuselage, and a member whose horizontal cross section extends substantially forward and backward of the fuselage at the upper center of the fuselage. This is achieved by having the following.

The above object can also be achieved by providing a hydraulic lateral force generating device in place of the aerodynamic lateral force generating device, which is formed by suspending a member whose horizontal cross section extends substantially in the longitudinal direction of the fuselage at the lower center of the fuselage. achieved.

[Effect]

In the present invention configured as described above, when the Hoha Craft runs with a small sideslip angle β when turning, the aerodynamic or hydraulic lateral force generator G generates an aerodynamic or hydraulic force in the lateral direction with the angle β as the angle of attack. A large lateral force (lateral force) acts, and this becomes a centripetal force that balances the centrifugal force. In particular, at high speeds, a large lateral force can be obtained even with an extremely small β, and only a small thrust is required.

〔Example〕

Hereinafter, the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a perspective view showing the appearance of the Hoha craft of this embodiment. In the figure, a skirt portion 2, for example, is provided around the fuselage 1 for air arc notification similar to conventional hovercraft.

A compressed air generator 3 having a propeller for supplying compressed air for levitation to the skirt portion 2 is provided at the front of the fuselage 1 . Furthermore, at the rear of the aircraft, there is a thrust generator 4 that generates thrust by expelling air to the rear.
have. The thrust generating device 4 is provided with a thrust deflecting vane 5 at the rear thereof for changing the direction of air flow.

Between the air generating bag W3 and the thrust generating device 4, a vertical plate 6 serving as an aerodynamic lateral force generating device in the form of an airfoil extending in the longitudinal direction stands vertically at a position approximately at the center of the fuselage l in the longitudinal direction. It is provided. In that case, the vertical plate 6 in the front and back direction
It is desirable that the aerodynamic center of the aircraft be located at or near the center of gravity of the aircraft.

The rear edge portion of the vertical plate 6 is a flap portion 6B whose direction is variable around the axis 6A. Note that the aerodynamic lateral force generating device does not have to be a vertical plate as described above, but may be a diagonal plate tilted in the lateral direction.

In this embodiment, as a preferred form, protrusions 7.7 extending rearward are provided on both sides of the fuselage l in order to increase stability against moments about the center of gravity of the fuselage due to lateral forces acting on the upright plate. However, a vertical stabilizer 8.8 is provided here. The vertical stabilizing plates 8, 8 are also connected to the vertical plate 6.
The rudder 8A, 8 has a flap shape similar to that in the case of
It has A. It goes without saying that if the aerodynamic center of the vertical plate almost completely coincides with the center of gravity of the aircraft, the vertical stabilizer plate is unnecessary.

When the hovercraft of this embodiment turns under thrust T with a side slip angle β as shown in FIG. 2, for the vertical plate 6, β becomes the angle of attack with respect to the headwind with a wind speed of ■. Air force acts on the vertical plate 6. The aerodynamic force can be decomposed into a lateral force directed toward the turning center O and a resistance force, and the lateral force balances the centrifugal force of the aircraft body. The aerodynamic force described above can produce a large lateral force compared to the resistance, so it goes without saying that a small sideslip angle (angle of attack) β is sufficient, but the thrust force T also needs to be small to counter the resistance. . This is a big advantage especially when driving at high speeds.

In this embodiment, in order to increase the lateral force, the flap portion 6B of the vertical plate 6 can be changed in direction.

This allows the sideslip angle β to be further reduced.

Furthermore, in this embodiment, the angle of attack β is also applied to the vertical stabilizers 8, 8.
A lateral force acts on the aircraft's center of gravity (C, G,)
It provides a moment to the surrounding area and achieves directional stability using a principle similar to that of a vertical stabilizer in an airplane. Further, fine adjustment is made by the rudder.

In this embodiment, when the vehicle is traveling straight and receives a crosswind, which would generate unnecessary lateral force, the lateral force is made zero by operating the hula knob.

In this embodiment, only one vertical plate is provided, but a plurality of vertical plates may be provided as in another embodiment shown in FIG. Also,
As shown in the figure, the vertical sheet metal body may be made rotatable so that the angle of attack can be changed without providing a flap part.

Further, in the embodiments described above, the upright plate is airfoil-shaped, but it may be a simple plate-shaped one. Although the efficiency is lower, it is extremely easy to manufacture. Moreover, the aerodynamic lateral force generating device can also be achieved by a sail instead of using a vertical plate.

Further, in the present invention, a hanging plate extending downward from the lower central portion of the fuselage may be used so as to obtain the lateral force by hydraulic force instead of by aerodynamic force. In this case, the hanging plate can be smaller than a vertical plate that utilizes aerodynamics, and the problem of obstructing visibility is also eliminated.

〔Effect of the invention〕

Since the present invention is provided with an aerodynamic or hydraulic lateral force generating device as described above, a large centripetal force can be obtained at a small sideslip angle when turning, so maneuverability and ride comfort are greatly improved, and the thrust can be small. This has the effect of greatly contributing to energy saving.

[Brief explanation of drawings]

Figure 1 is a perspective view showing the appearance of a hovercraft according to an embodiment of the present invention, Figure 2 is a plan view showing the balance of forces when the hovercraft of Figure 1 turns, and Figure 3 is a hovercraft of another embodiment. FIG. 4 is a plan view showing the balance of a conventional hovercraft when turning. 1...Flexible body 2...Skirt section 6...Aerodynamic lateral force generator (vertical plate)

Claims (6)

[Claims] (1) A hovercraft that has an air cushion section at the bottom of the body and is equipped with an aerodynamic lateral force generating device formed by erecting a member whose horizontal cross section extends substantially in the longitudinal direction of the body at the center of the upper part of the body. (2) The hovercraft according to claim (1), wherein the aerodynamic lateral force generator is a vertical plate. (3) The hovercraft according to claim (1), wherein the vertical plate has an airfoil-shaped horizontal cross section. (4) The hovercraft according to claim (1), wherein a plurality of aerodynamic lateral force generators are installed upright. (5) The hovercraft according to claim (1), wherein the aerodynamic lateral force generator has a variable angle of attack. (6) A hovercraft which has an air cushion section at the bottom of the machine body and is equipped with a hydraulic lateral force generating device formed by hanging a member whose horizontal section extends substantially in the longitudinal direction of the machine body from the lower central part of the machine body.