JPH04297865A - Reverberation free water tank - Google Patents

Abstract

PURPOSE:To prevent reflection of sounds in water with a water tank wall by a method wherein an acrylic resin plate is applied on the side and bottom surface of a water tank leaving a clearance and a plurality of bubble generators are arranged in the clearance to absorb the sounds in the water. CONSTITUTION:A side plate 6 and a bottom plate 7 made of an acrylic resin are arranged in parallel on side walls and the bottom surface surrounding a water tank. A bubble path 8 is provided between the side plate 6 and wall surfaces and the bottom plate 7 and the bottom surface to let bubbles 3 ascend as generated from respective bubble generators 2a... and 2h and a plurality of air discharge ports are arranged to release air into the water. For example, a sound wave P radiated by vibration of a model ship 5 reaches the side plate 6 and the bottom plate 7. But as an acoustic impedance pc of an acrylic resin is almost equal to water 4, the sound wave P excites vibration of the bubbles 3 in the bubble path 8 without being reflected. Thus, the energy of the sound wave P is absorbed by the bubbles 3 and the sound wave which is reflected on the wall and bottom surface of the water tank and returned to the water 4 becomes very weak.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an anechoic water tank.

[Conventional technology]

Conventionally, in an anechoic tank, as shown in the sectional view of FIG. I am trying to create a free sound field similar to that of .

[The problem that the idea attempts to solve]

However, in this type of anechoic aquarium, it is important to create a free sound field in which the radiated sound attenuates with distance, but a sufficient free sound field may not be formed due to the sound reflecting off the tank walls. be.

The present invention was proposed in view of the above circumstances, and its purpose is to provide an anechoic aquarium in which underwater sounds are not reflected by the aquarium walls.

[Means to solve the problem]

To this end, the present invention has acrylic resin side wall plates and acrylic resin bottom wall plates that are stretched along the sides and bottom of the aquarium with appropriate gaps, and the acrylic resin bottom wall plates are placed vertically and horizontally at appropriate intervals in the above-mentioned gaps of the aquarium. The invention is characterized by comprising a plurality of bubble generators.

[Effect]

According to this configuration, the vibration of the bubbles is excited just before the sound waves reach the water tank wall, and the energy is absorbed by the bubbles, so that the sound waves are no longer reflected by the water tank wall surface.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view thereof, and FIG. 2 is a horizontal sectional view of FIG. 1.

In the above figure, side plates 6 and bottom plates 7 made of acrylic resin are arranged in parallel with each other, with slight gaps between the side walls and the bottom of the four circumferences of the aquarium.

Bubble passages 8 are formed between the acrylic resin plates 6, 7 and the aquarium wall surface 1, through which the bubbles 3 generated from the bubble generators 2a, 2b, . . . , 2h ascend.

The bubble generators 2a, 2b, . . . 2h are pipe-shaped and have a large number of air discharge ports, from which air is sent into the aquarium.

[Effect of idea]

According to such a structure, for example, the sound waves P emitted by the vibrations of the model ship 5 can be transmitted to the side plates 6 and the bottom plate 7 made of acrylic resin.
At this time, since the specific acoustic impedance ρc of the acrylic resin is approximately equal to that of the water 4, the sound wave P reaches the bubble passage 8 without being reflected.

Then, the sound wave P excites the vibration of the bubble 3 in the bubble passage 8 without being reflected, so the energy of the sound wave P is transferred to the bubble 3.
The sound waves that are absorbed by the aquarium, reflected by the aquarium wall 1, and returned to the water 4 in the aquarium become very weak.

Therefore, it is possible to make the aquarium anechoic.

In short, according to the present invention, acrylic resin side wall plates and acrylic resin bottom wall plates are stretched along the sides and bottom of the aquarium with appropriate gaps between them, and the acrylic resin bottom wall plates are arranged vertically and horizontally at appropriate intervals in the above-mentioned gaps of the aquarium. The present invention is industrially very useful because it provides an anechoic aquarium in which underwater sound is not reflected by the aquarium wall by providing a plurality of bubble generators.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is a horizontal sectional view of FIG. 1. FIG. 3 is a longitudinal sectional view showing a known anechoic water tank. 1...Aquarium wall, 2, 2a, 2b...bubble generator, 3...bubble, 4...water, 5...model ship, 6...acrylic resin side plate, 7...acrylic resin bottom plate, 8...bubble passage, agent patent attorney Masafumi Tsukamoto

Claims (1)

[Claims] Acrylic resin side wall plates and acrylic resin bottom wall plates are stretched along the sides and bottom of the aquarium with appropriate gaps,
An anechoic water tank characterized by comprising a plurality of bubble generators arranged vertically and horizontally at appropriate intervals in the gaps of the water tank.