1. Mechanical effects. The mechanical action of ultrasound can promote the emulsification of liquids, the liquefaction of gels and the dispersion of solids. When a standing wave is formed in the ultrasonic Portable ultrasound fluid medium, the tiny particles suspended in the fluid are condensed at the nodes due to mechanical force.

Form periodic accumulation in space. When ultrasonic waves propagate in piezoelectric materials and magnetostrictive materials, induced electrical polarization and induced magnetization are caused by the mechanical action of ultrasonic waves.

2. Cavitation. When ultrasonic waves act on liquids, a large number of small bubbles can be produced. One reason is that partial tensile stress occurs in the liquid to form a negative pressure. The decrease in pressure makes the gas originally dissolved in the liquid supersaturate and escape from the liquid and become small bubbles. Another reason is that the strong tensile stress "tears" the liquid into a cavity, which is called cavitation.

Application of Ultrasonic Waves whose frequency is higher than the upper limit of human hearing (approximately 20,000 Hz) are called ultrasonic waves.  The law of reflection, refraction, diffraction, and scattering of ultrasonic waves in the medium is not essentially different from the law of audible sound waves. But the wavelength of ultrasound is very short, only a few centimeters, even a few thousandths of a millimeter. Compared with audible sound waves, ultrasonic waves have many strange characteristics: propagation characteristics-the wavelength of ultrasonic waves is very short, and the size of usual obstacles is many times larger than the wavelength of ultrasonic waves. Therefore, the diffraction power of ultrasonic waves is very poor. It is in a homogeneous medium. It can propagate in a directional straight line, and the shorter the wavelength of the ultrasonic wave, the more significant this characteristic is. Power characteristics-when sound propagates in the air, it pushes the particles in the air to vibrate back and forth to do work on the particles. The power of the sound wave is a physical quantity that expresses the speed of the sound wave's work. Under the same intensity, the higher the frequency of the sound wave, the greater the power it has. Due to the high frequency of ultrasonic waves, the power of ultrasonic waves is very large compared with ordinary sound waves. Cavitation-When ultrasonic waves propagate in the liquid, small cavities are created in the liquid due to the violent vibration of the liquid particles. These small cavities expand and close rapidly, causing violent collisions between the liquid particles, resulting in pressures of thousands to tens of thousands of atmospheres. This violent interaction between the particles will cause the temperature of the liquid to rise suddenly and play a good stirring effect, so that the two immiscible liquids (such as water and oil) emulsify and accelerate the dissolution of solutes. Speed ​​up the chemical reaction. The various effects caused by the action of ultrasonic waves in the liquid are called ultrasonic cavitation.

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