JPS58225339A - Wave forming apparatus - Google Patents

Abstract

PURPOSE:To obtain a wave with a desired fine wave form even in a stream having a flow speed, by rotating a cylinder provided in parallel relation to flat water surface around an eccentric axial core. CONSTITUTION:A cylinder 2 substantially parallel with a flat water surface H is provided to the upstream side of the test region 1 of a circular stream water tank and rotated around an eccentric axial core P separately provided in parallel relation to the axial core Po of said cylinder 2 so as to sink at least the part thereof below the water level to form a predetermined wave W to the downstream side test region 1 of said cylinder 2. A wave control mechanism 3 is provided along the flat water surface H in the upstream side relative to the upstream side of the cylinder 2, that is, the test region 1 as a wave forming water surface and a plate shaped body 6 internally inlaid with a case 5 having a compression spring 4 mounted to the bottom part thereof in a freely retractable manner is provided so as to always contact the leading end thereof with the outer peripheral surface of the cylinder 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wave-making device used when conducting experiments in waves such as a wave-making resistance test of a ship in a hydrodynamic test tank such as a towed water tank or a circulating water type water tank.

As a conventional wave-making device, one having a configuration as shown in FIGS.

The one shown in 1st FA&) is called a flap type, which generates waves W by reciprocating the submerged plate a around the axis, and the one shown in Figure 1 (b) is a plunger type. P?
Waves W are mainly generated by reciprocating the submerged body C of the cross-sectional wedge ib up and down with respect to the horizontal water surface d.

However, when such a wave-making device with a conventional configuration generates waves in a stationary fluid such as a towed water tank, the problem is I11! However, it could not be applied in cases where waves are generated in a flow with a flow velocity such as in a recirculating water tank, which has recently become more popular due to its usefulness in warehouses. .

This is because, regardless of whether it is a flap type or a Francia type, during flow t, downstream of submerged plate a or submerged body C,
This is because because a relatively strong vortex f is generated on the side, the waveform is greatly disturbed, making it impossible to obtain a desired wave, and therefore making it impossible to conduct experiments with high precision.

In addition, all of these conventional wave-making devices require a mechanism for converting rotational movement such as Tanabata into reciprocating linear movement, which has the disadvantage that the overall structure becomes complicated and large. From this point of view, L&D was applicable to small circulation water tanks.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to be able to generate waves with a desired clean waveform even in a flow having a flow velocity, and to have a compact structure as a whole. We provide wave-making equipment that can
The purpose of this invention is to make it possible to realize accurate 11i+ in waves in a circulating water tank, which has been thought to be almost impossible until now.

The following are diagrams illustrating embodiments of the present invention (Figures 2 to 4).
I will explain based on.

FIG. 2 shows the basic configuration of the wave-making device according to the present invention,
A cylindrical body 2 is installed substantially parallel to the flat wood surface H on the upstream side of the test area 1 of the same flow water tank, and this cylindrical body 2 is
The upstream side of the forward or reverse rotating cylindrical body 2, that is, the wave-making water surface, is centered on the eccentric axis P, which is separately installed parallel to the axis PO, so that at least a part of the cylindrical body 2 is submerged in water. A wave control mechanism is provided along the flat water surface H on the upstream side of the test area 1, and includes a compressed suffling 4 at the bottom.
The plate-like body 6 is removably fitted into the case 5 containing the cylindrical body 2, so that the tip of the plate-like body 6 is always connected to the cylindrical body 2.
It is configured so as to come into contact with the outer peripheral surface of.

Note that the tip of this plate-like body 6 is made of a soft material such as rubber or sponge. By providing this wave control mechanism 3, it is possible to prevent waves that would normally be generated from being generated on the upstream side of the IJ cylinder body 2, thereby increasing the wave-making efficiency on the downstream side of the cylinder body 2. It is possible to almost double the amount, and at the same time, it is possible to reduce the disturbance of the waveform.

When there is no flow velocity V (stationary fluid), the wave height and wave height generated by the wave making device having the above configuration are determined by the rotational speed of the cylindrical body 2 and the two axes Pa in mr.

It is determined by the distance t between P, and when there is a flow velocity (2), it is determined by the rotation speed of the cylindrical body 2, the distance between the two axes Po, P, and the magnitude of the flow velocity v. Therefore, in the above wave making device, both the rotational speed of the cylindrical body 2 and the distance t can be changed and adjusted.

Then, the relationship between the flow velocity (2), rotation speed, distance t, wave period and wave height was determined through experiments and made into a table. Therefore, given a predetermined flow velocity (2) and a desired wave circumference 3111 and wave height, the rotation speed and distance @1 of the cylindrical body 2 can be easily determined from the table. According to experiments, when the flow velocity ■ is small (approximately 0.15 m/sec or less), it is better to rotate the cylindrical body 2 in the opposite direction (see the figure).
It was observed that when the dust is large, a clean waveform with less distortion can be obtained by rotating the waveform at a fixed angle of 1υj.

In addition, it has been found that it is appropriate to arrange the cylindrical body 2 so that its lower end is in contact with the flat wood rkIH when it is at its highest position, as shown in this figure, in order to obtain a beautiful waveform.

3 and 4 show the specific structure of the wave-making device according to the present invention.

8.8 are both side walls of the test area 1 of the circulating water tank, and it l!
A pedestal 9 in the shape of a square U is placed thereon. From the left and right ends of this frame 9, shaft supporting members 12 and 12 with built-in thrust bearing links, which have a relatively large amount of suspension, hang down via the screw shafts 1 (1, 10 and nuts 11, etc.) in a vertically adjustable manner. These two shaft supports 112, 1.
Said cylinder 2 via a cup link 13.13 between 2
is supported by the 1111 rotating shaft in the direction of the eccentric axis PJ. This eccentric axis P is located at -1] lower position N with respect to the cylindrical body 2.
Changeable and adjustable.

This eccentricity - 11 core P word 111i'J4@structure 14.14
It is structured like a box. That is, one axis 15. I!
5 is freely rotatable, and this i, 11+ IP+
, 15 are fitted with the frame members 1fi, lci connected to the camp ring 13.13, so that the screw shaft 15. By moving +5 by 1r'', the cylindrical body 2
ff'? to change and adjust the relative upper positions of the cup links 13 and 13, and adjust the upper and lower positions of the eccentric shaft center P. It was completed.

One of the camp rings 13 and 13 is configured as a hub pulley and connected to a pulley 19 which is rotationally driven by a motor 18 via a tension belt 17.
, + are connected. 20 is a rotation speed control device.

Note that 21 and 21 in the figure are partition walls, and the outer space thereof is filled with grease. 22. 22 is a two-split rubber member for sealing provided inside the long holes 25, 25 on the side of the cylindrical body 2; 2+1, 23 are above the eccentric axis P;
A scale is provided on the side surface of the cylindrical body 2 to read the position of the cup link 13. Reference numerals 24 and 24 are pointers projecting horizontally from a position corresponding to the eccentric axis P of the cup link 13.13. Further, 26 and 26 are spirit levels.

In summary, the wave-making device according to the present invention has a cylindrical body installed substantially parallel to a flat water surface, and a state in which at least a part of the cylindrical body is submerged in water around an eccentric axis parallel to the axis of the cylindrical body. It is characterized by being configured so that it can be rotated by.

In the wave-making device according to the present invention having the above characteristic configuration, it can be used as a wave-making object not only in a stationary fluid such as a towing water tank that generates a vortex on the downstream side when placed in a flow as in the past. , it is possible to obtain waves with the desired clean waveform even in a flow with a high velocity such as in a circulating water tank, and this makes it possible to conduct experiments for each phase in waves using a circulating water tank, which was virtually impossible until now. This will greatly contribute to the development of industry and academia. Furthermore, unlike conventional equipment, the required force to convert the rotational motion of the drive device into a linear reciprocating motion of 1°111tll is reduced to 1.
This configuration is extremely convenient for placing this point force in a relatively small, type circulating water tank.

A schematic cross-sectional view showing the process in Figure 3 and a partial cross-section dorsal blood diagram at 11, and Figures 4 and 3. be.

2... Cylindrical body, 3... Wave control mechanism, 6... Plate-shaped body,
14... Interval change adjustment mechanism, 20... Rotation speed change i11 flf+ device, 11... Flat water surface, PO...
Axial center of cylindrical body 2, ■)... Unbalanced tu Ml + core.

Claims (1)

[Claims] ■ A cylindrical body 2 installed parallel to a horizontal water surface 11 at an inclusive angle,
A wave-making device characterized in that it is configured to rotate around an eccentric axis P parallel to the -1 core PO so that at least a part of the cylindrical body 2 is submerged in water. and t. 0) A mechanism 14 is provided for changing and adjusting the distance t between the axis Pa of the rlIl diary body 2 and the eccentric axis P of n1j. The wave-making device described. (2) The wave-making device according to claim 0 or (2), wherein the device ^20 for changing and adjusting the N rotation speed of the n+1 cylindrical body 2 is a device. ■ r? The flat water m1 on the upper side of the cylindrical body 2 was pressed so that it was always in contact with the circumferential surface of the cylindrical body 2. A special feature characterized in that a wave control mechanism 3 equipped with a plate-like body 6 is provided.
f The wave-making device according to any one of claims 0 to 0. (2) The wave-making device as set forth in item 0 of the range of requirement #l-Rh, characterized in that the tip of the plate-like body 6 of the wave control mechanism 3 is formed of a soft material.