Why does the water rattle when you boil it

The bursting of the bubble was a cause, gurgling, but the sound was so small that you had to get closer to hear it. The "beeping" kettle or "chirping" kettle at home is loud because the steam lifts a small piece of iron on the spout and vibrates to make a sound.

Found a passage from a physics book-

When the water starts to heat up, the bottom of the kettle creates some small bubbles that are mainly formed by the air adsorbed on the bottom of the kettle and dissolved in the water. In addition to air, the bubble also contains water vapor generated by heating, and as the temperature rises, the water vapor evaporating into the bubble gradually increases, and its volume and pressure will increase, and it rises from the bottom under the action of buoyancy. When the bubble rises to a lower temperature, part of the water vapor in the bubble condenses into water, and the external pressure is stronger than the pressure inside the bubble, and the volume of the bubble gradually decreases.

In the process of continuous heating, the bubbles are generated and expanded more and more, and they are larger and larger, but when the bubbles rise to a lower temperature, the water vapor in the bubbles will condense into water, and the volume will gradually decrease. In such a process, as the temperature rises, the volume of the bubble expands and shrinks for a while, and then rises continuously, resulting in a kind of vibration. If the frequency of this vibration is the same as the natural frequency of the kettle, it will resonate and emit sound.

In addition, there are still bubbles running out of the water, so that the pressure of the gas in the space that does not contain water in the pot increases, and a part of the gas will be squeezed out of the gap between the lid and the body of the pot, and the sound will also be generated. For these two reasons, we hear the sound of water, and the sound of water is getting louder and louder. This sound is made when the water is not yet boiling, and is generally "hum, hum, hum......Voice.

When the temperature of the water reaches the boiling temperature, the inside of the water vaporizes sharply, the water vapor in the bubble reaches saturation, the density atmospheric pressure is high, and its volume not only does not shrink during the ascent process, but also continues to increase. At this time, the buoyancy of the bubble also increases during its rise, and the bubble rises from the bottom to the surface and bursts, releasing water vapor, and the resonance between the bubble and the kettle does not exist, and the sound of water becomes smaller. Then a large amount of gas will be discharged from the gap, the large air pressure will lift the lid of the pot, and after the lid is lifted, a part of the gas will be discharged, and the pressure will be reduced; It falls again under the action of gravity, and the air pressure increases again after the lid is lifted, and so on and so on, so it turns into a "horn, horn, horn...... of water vapor pushing the lid of the potWatt invented the steam engine based on the principle of water vapor pushing the lid of the kettle.

If the water in the kettle is not full, the water surface is below the interface between the spout and the body of the kettle, or the gap between the lid is large, in this case, the water vapor pushing the lid "horn, horn, horn...... will not be heardA large amount of water vapor will come out of the spout or cracks, and the sound is very small or even no sound, so as the saying goes, "boiling water does not sound, and sound water does not boil".

When boiling water, due to heat convection, the upper and lower temperatures are different, and bubbles are produced due to the pressure effect. The air in the bubble expands and contracts and bursts, vibrating and making sounds. And when boiling, the heat convection is strong and the sound is louder.

The gas dissolved in the water, due to the increase in temperature, the solubility becomes smaller, the gas overflows, and the bubbles burst at the surface of the water, making the water vibrate and make a sound!

The sound is produced by vibration, and the sound when boiling water is due to the sound produced when the water violently shakes the water container. It's not that the bubble bursts, and the bubble burst can't make that loud noise.

The water inside vaporizes, and the bubbles go to the surface of the water, getting bigger and bigger, and finally bursting, producing a sound similar to **, so there is a sound.

Because when the water is boiled, water vapor is generated, and it is boiling

The boiling of water produces oscillations, so there is a sound.

The sound of steam moving out of a kettle.

The bubbles in the water are vibrating.

Watt asked this question when he was young.

It should be that when the water heater is heated, the water is cold before heating, so when the heating is energized, the cold water will make a sound, and under the action of atmospheric pressure, the water temperature and the surface temperature of the heating tube will disappear when the water is boiled, and the sound can only be heard at the boiling sound of the water. Or the sound of the heating rod and the bottom plate being heated and expanding, after a long time, it will accumulate scale, and the scale is a bad conductor of heat, which will make the kettle bottom plate unevenly heated, so it will make a sound, which is also normal.

Extended Materials. A water heater is a device that turns the temperature of cold water into hot water in a certain period of time through various physical principles. According to different principles, it can be divided into electric water heaters, gas water heaters, solar water heaters, magnetic energy water heaters, air energy water heaters, heating water heaters, etc.

Manufacture of air-conditioning part and manufacture of hot water section. In fact, these two parts are closely linked, inseparable, and must work at the same time. That is, to produce hot water and cool the kitchen at the same time. Or rather, while cooling the kitchen, it is also producing hot water.

Yes, it is quiet at the beginning and loud when it is about to boil.

When it comes to boiling water, I believe everyone has done it, and careful friends will find that when the water is boiled, there will be a very loud sound, which is also a reminder that the water is to boil, so some people may have doubts, why does the water sound when it boils? Let me answer your questions.

It turns out that before the kettle is filled with water, a layer of air is adsorbed on the wall of the kettle, and after adding water, this layer of air becomes countless tiny bubbles. Because the adsorption force is greater than the buoyancy of the bubbles, the water cannot pull them out of the walls of the pot.

When the water temperature rises, the water around the bubble evaporates in the bubble, so that the volume of the bubble increases, when the temperature reaches seventy or eighty degrees Celsius, the buoyancy of the larger bubbles exceeds the adsorption force, and they will leave the wall of the pot and rise, while still leaving a part of the air on the wall of the pot, this part of the air will increase the volume at a faster rate and rise.

When the rising bubble encounters the surrounding cool water, the water vapor in the bubble will liquefy, causing the bubble to quickly become smaller or burst. As countless bubbles expand sharply at the bottom of the pot and quickly become smaller in the rise, the water in the pot is in a state of intense vibration, which in turn causes the air to vibrate, forming a water acoustic.

Because the volume of the bubble changes very quickly, the vibration frequency of the water is high, and the tone of the water sound is also high. Later, as the temperature difference between the various parts of the pot becomes smaller and smaller, the volume of the bubbles alternates more and more slowly, and the tone of the water sound caused by this gradually decreases. When boiling, the bubbles burst on the surface of the water, causing a large churning of the water surface, and the resulting air vibration frequency is much lower than the former, and the tone of the water sound is also lower.