How do Wave Pools Work?

In 1956, the Netherlands first built a long and narrow pool, with many units on the adjacent sides equipped with wave-type wave-making machines. Changing the swing phase difference of each unit's rocking plate can cause waves in various directions. This kind of wave-making machine is sometimes called snake-type wave-making machine, which can make regular wave of sine and irregular wave of various spectrum.

In 1956, the Netherlands first built a long and narrow pool, with many units on the adjacent sides equipped with wave-type wave-making machines. Changing the swing phase difference of each unit's rocking plate can cause waves in various directions. This kind of wave-making machine is sometimes called snake-type wave-making machine, which can make regular wave of sine and irregular wave of various spectrums.

Chinese name

Wave pool

Foreign name

wave basin

Nature

Equipment for hydrodynamic experiment

Wave Pool Overview

A device for hydrodynamic experiments that uses artificial waves to simulate waves. Artificial wind can be used to simulate natural wind on the water surface of the pool; it can also be made to flow to simulate ocean currents. A pool that can simulate wind, waves, and flow is called a wind wave flow pool.

Wave pool effect

It can be used to test ship models, to estimate the ship's motion, stall, propulsion efficiency and wave load. It can also be used for related tests on various marine structures.

Example of wave pool

The waves created in this wave pool are binary. Tracks are laid on the pool walls on both sides, and a trailer walks on the track, drags the ship model, and tests.

The United States Navy built a wave pool in 1961 (see the wave pool example), 98.3 meters long, 73 meters wide, and 6.1 meters deep, and a bridge was set up. Two adjacent sides of the pool are equipped with air wave maker. The bridge can be rotated 45 °, there are two tracks on the bridge, the trailer is running on it, and the tow boat model is traveling at various speeds and testing at various angles with the waves.

China Ship Scientific Research Center (Wuxi) built a wave pool of the same type in 1971, 69 meters long, 46 meters wide and 4 meters deep.

A wind and wave pool was built in Norway in 1980, with a length of 80 meters, a width of 50 meters, a depth of 0-10 meters, and a velocity of 0.2 meters per second. The bottom of the pool can be raised and lowered to simulate different water depths.

In the 1970s, some tow tanks hung a small frame under the traction frame. When the main frame was used for longitudinal travel, the small frame was used for lateral travel. In this way, the model hung under the small carriage walks along the specified heading, that is, at a certain angle with the waves generated by the pool-side wave-making machine. This form of frame is called an xy frame.

During the ship model test, the ship model can be towed by a trailer, or can be propelled by propellers; it can sail on a regular sine wave or on an irregular wave. The spectrum of actual waves can be simulated with the spectrum of different irregular waves. It can be used for the test of heading, following the waves and sailing at various angles with the waves. In recent years, some pools use transient waves (or transient waves) for ship model motion tests. Transition waves are the same group of regular waves with different periods superimposed. After data analysis, the corresponding function of ship model motion can be obtained.

When doing ship model tests, the similarity rate must be observed, that is, the model is similar to the prototype geometry, the center of gravity is similar, the inertia is similar, and the Froude number is equal.

There are three main types of wave-making machines: air type, rocker type and punch box type. The opposite side of the pool wave-maker must be equipped with a wave-removing shore to eliminate the incoming waves and prevent the waves from reflecting back and causing interference.

The longitudinal motion test of the ship model must measure the ship's speed, heave, pitch, wave height and period, and if necessary, the ship model's movement acceleration. The lateral motion test generally requires measuring the height and period of the wave, and the roll and sway of the ship model. The oblique wave test shall measure all data for longitudinal and lateral motion.

Due to the rise of offshore oil exploration, in the process of developing offshore oil exploration and production platforms, model tests must be carried out in wave pools to predict the forces, drifts and movement states of structures.