JPH035196Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is a drifting buoy, especially in the direction of ocean wave arrival.
This paper relates to the structure of a drifting buoy for long-term observation of seawater temperature, concentration, ocean surface wind power, etc.

(Prior art) Conventionally, drifting buoys released to measure the state of ocean currents in the ocean have generally been cylindrical or truncated conical, and the measurement items have been limited to seawater temperature. In order to keep the attitude of the buoy as constant as possible with respect to the sea surface and maintain the depth of the seawater temperature sensor, a weight was suspended like a sea anchor, but no consideration was given to preventing the buoy from rotating, nor was there any need for such measures. It almost never occurred.

However, when using a drifting buoy to measure the arrival direction of waves or ocean surface winds, and installing necessary equipment such as accelerometers and magnetic compasses in the buoy to detect the arrival direction of waves, the buoy itself Although it is necessary to reduce the speed of rotation, a drifting buoy with the shape described above is not only susceptible to rotation due to the shape of the portion above the water line, but also has almost no function to prevent rotation. For some reason, the observation results were completely unreliable.

(Purpose of the invention) The present invention was made in view of the deficiencies of the conventional drifting buoy as described above, and is a drifting buoy that can improve the accuracy of observation results in means for detecting the arrival direction of waves. The purpose is to provide buoys.

(Summary of the invention) Therefore, in the present invention, the buoy body that houses a means for detecting the arrival direction of waves inside is formed into a substantially spherical shape, and the buoy body is attached to the outer wall below the water line of the buoy body from the side The above objective was achieved by providing protruding fins whose projected area was 20% or more of the projected area of the drainage section of the buoy body.

(Embodiments of the invention) The invention will now be described in detail with reference to embodiments shown in the drawings.

Before explaining the present invention, a conventional drifting buoy will be briefly explained.

FIG. 2 is a side view showing the shape of a conventional drifting buoy. By making the buoy body 1 a substantially perfect sphere made of aluminum, the part above the water line, that is, the part of the drifting buoy in operation, can be placed on the water surface. This is intended to minimize the influence of wind on the upwardly protruding portion and to minimize the occurrence of pins.

Incidentally, 2, 2, . . . are legs for setting on the ground and are fixed to the main body 1, and 3 is a lid for attaching and detaching tower-mounted equipment within the buoy main body.

A drifting buoy with such a shape has a spherical freeboard, so rotation due to ocean surface winds is minimized, but the area below the waterline is susceptible to rotation due to the influence of ocean currents, and its rotation speed increases considerably. That's right.

In order to solve this problem, the drifting buoy according to the present invention has a configuration as shown in FIG.

That is, on the outer wall of the buoy body 1 below the water line, the projected area of the drainage part of the buoy body 1, that is, the approximately semicircular area when the part of the buoy body 1 below the water line is viewed from the side. , about 25
The anti-spin fins 4 and 5, each having a projected area of 50%, are provided in a protruding manner to form a cross.

The anti-spin effect of the buoy of the present invention equipped with such fins will be explained below using experimental examples.

Figure 3 shows the same date and time, the same sea level, no fins, and the fin area relative to the projected area of the drainage area.
%, 20%, 25%, and 35% buoys were prepared and released into reality, and the results of measuring their rotational speeds were summarized.

As is clear from the results of this experiment, when the fin area becomes about 15% of the projected area of the drainage part, the spin prevention effect of the fin becomes clear, and when it exceeds 25%, it becomes almost saturated.

In other words, it was found that, at least for spherical buoys, if fins with a projected area of approximately 20% or more of the projected area of the drainage area are attached, the rotation of the buoy due to the influence of ocean currents can be significantly alleviated. .

As mentioned above, the drifting buoy according to the present invention can suppress spin very effectively. Therefore, in a drifting buoy equipped with an acceleration sensor, especially a gyroscope type acceleration sensor, to detect the direction of arrival of waves, In addition to reducing the acceleration detection error of accelerometers due to spin, it also makes it easier to follow the north direction of a magnetic compass for determining absolute direction, and is extremely effective in accurately measuring the direction of wave arrival. It should be noted that the optimal value of the ratio of the fin area to the projected area of the buoy main body drainage area is difficult to perform a theoretical analysis due to constantly changing ocean conditions, so it would be safe to determine it through experiments. Further, the arrangement of the fins does not necessarily have to be in the form of a cross, but may be arranged in three fins arranged at 120° angles.

In this case, the fins may be designed so that the projected area of the entire fin is greater than or equal to the projected area of the buoy drainage section no matter what direction the buoy side surface is viewed from.

(Effects of the invention) As detailed above, according to the drifting buoy related to the invention, the buoy body is formed into a substantially spherical shape, and the outer wall of the buoy body below the water line has a projected area from the side. By protruding spin prevention fins formed at 20% or more of the projected area of the drainage part of the buoy body, it is possible to keep the rotation speed of the drifting buoy as low as possible, thereby preventing the arrival of waves. It has become possible to improve the accuracy of observation results in means of detecting direction.

[Brief explanation of the drawing]

Figures 1a and b are side and rear views showing an embodiment of a drifting buoy according to the present invention, Figure 2 is a side view showing the external shape of a conventional drifting buoy, and Figure 3 is a conventional buoy and a book. It is a figure which shows the result of the comparative experiment regarding the rotation speed with the buoy based on an invention. 1...buoy body, 4, 5...fin.

Claims (1)

[Scope of Claim for Utility Model Registration] A buoy body that is approximately spherical in shape and houses a means for detecting the direction of arrival of waves; A drifting buoy equipped with anti-spin fins, comprising: anti-spin fins having a projected area of 20% or more of the projected area of the drainage part of the buoy body;