JPS6234280Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a circulating water tank that can be used commonly for experiments on ships and experiments on fisheries such as fishing nets.

Literature related to the circulating water tank includes, for example, Turbomachinery (Vol. 4, No. 8, September 1976, No. 28-
There is a 38 page "Current status and problems of circulation water tanks" (Turbo Machinery Association).

As shown in Figure 1, water in a circulation channel a is circulated by a circulation impeller b, and in a circulation water tank in which a fluid dynamics experiment is conducted in a measuring section c (in the figure, d is a drive motor, and e is a water flow direction). ), the measurement part c is a so-called open channel with a free water surface f, so if the bottom surface g of the measurement part is designed horizontally as shown in Figure 2, the free water surface f will not be horizontal and the flow velocity will change. In other words, the water surface is tilted by an amount corresponding to the friction loss between the water flow flowing through the measuring section and the flow channel wall surface (the tilt angle is expressed as θ). (resistance test, etc.), accurate measurements cannot be made. For this reason,
In the circulating water tank used for ship experiments, as shown in Fig. 3, the bottom surface g of the measuring section is made to be an inclined surface with an inclination angle θ to match the inclination of the water surface, so that the water surface f can be kept horizontal. .

On the other hand, in experiments related to fisheries such as bottom trawl fishing, the bottom surface g of the measuring section is mainly used, so if the bottom surface g of the measuring section is inclined, accurate measurements cannot be made.

For this reason, conventionally, the circulating water tank used for experiments on ships and the circulating water tank used for experiments on fishing nets, etc. could not be shared, and separate equipment had to be prepared for each.

In view of the above, the present invention was devised to provide a circulating water tank that can be used commonly for experiments for ships and fisheries such as fishing nets. It is characterized by having a double bottom plate consisting of an inner bottom plate that can rotate around the upstream end and a fixed outer bottom plate.

By rotating the inner bottom plate around the upstream end and tilting it at the required angle, the free water surface of the measuring section is kept horizontal, making it possible to use the circulating water tank for experiments on ships, etc. By keeping the measurement unit level, the bottom surface of the measuring section becomes horizontal, and experiments with fishing nets and the like can be conducted in the circulating water tank.

Embodiments of the present invention will be described below with reference to the drawings.

4 to 6 show the present invention implemented as a vertical circulation water tank, with a measuring section 2 installed in the middle of the circulation channel 1.
is provided, and water in the circulation channel 1 is circulated in the direction of arrow 4 by the rotation of the circulation impeller 3, so that a fluid dynamics experiment is conducted in the measuring section 2. The measuring section 2 is constructed as an open channel having a free water surface 5, the bottom of the measuring section 2 has a double bottom structure composed of an inner bottom plate 6 and an outer bottom plate 7, and openings at both ends of the flow path of the measuring section 2 are configured as a circulation flow path. The upstream end of the inner bottom plate 6 is supported by a hinge 9. The outer bottom plate 7 is in a fixed state. A vertical movement device 11 such as a cylinder device is connected to the lower surface of the downstream end of the inner bottom plate 6 via a hinge 10, and the operation of the vertical movement device 11 causes the inner bottom plate 6 to rotate around the hinge 9.
It is designed to be held horizontally or tilted at an appropriate angle. Further, a water level gauge 12 is provided to detect the water level on the downstream side of the measurement section flow path, and a signal from the water level gauge 12 is amplified by an amplifier 13 and sent to the vertical movement device 11.

In the figure, 14 is a motor that rotates the circulation impeller 3, 15 is a column that supports the vertical movement device 11, and 16 is a motor that rotates the circulation impeller 3.
is a watertight device (bellows) of an opening provided in the outer bottom plate 7 for connecting the vertical movement device 11 to the inner bottom plate.

When conducting a ship experiment using the circulating water tank configured as described above, the horizontality of the free water surface 5 of the measuring section is detected based on the signal from the water level gauge 12, and the detected signal is amplified by the amplifier 13. The inclination angle θ required to keep the free water surface 5 horizontal is sent to the vertical movement device 11.
The vertical movement device 1 tilts the inner bottom plate 6 to
1. In contrast to the above, if the inner bottom plate 6 is kept horizontal, the bottom surface of the measuring section will be horizontal, and the tank can be used as a recirculating water tank for experiments such as fishing nets.

Note that the present invention can also be implemented as a model circulating water tank that circulates water in the horizontal direction.

As mentioned above, the present invention has a tiltable bottom plate on the measuring section, so it can be used for both ship experiments and fishing net experiments, which can significantly reduce equipment costs and improve experimental accuracy. can.

[Brief explanation of the drawing]

Figures 1 to 3 are explanatory diagrams of the conventional device, Figure 4 is an elevational view of the recirculation water tank of the present invention, Figure 5 is an explanatory diagram of the measuring section of the present invention, and Figure 6 is the -
It is an arrow view. DESCRIPTION OF SYMBOLS 1...Circulation channel, 2...Measurement part, 4...Circulation direction, 5...Free water surface, 6...Inner bottom plate, 7...Outer bottom plate, 11...Vertical movement device, 12...Water level gauge.

Claims (1)

[Scope of utility model registration request] A circulating water tank having a measuring section provided in the middle of a circulation channel, characterized in that the measuring section is provided with a double bottom plate consisting of an inner bottom plate that can rotate around an upstream end and a fixed outer bottom plate. A recirculating water tank.