Warmth from nowhere. Drawing, description

CHILDREN'S SCIENTIFIC LABORATORY
Free library / Directory / Children's Science Lab

Warmth from nowhere. Children's Science Lab

Children's Science Lab

...This experiment by an American by the name of Griggs, staged almost 10 years ago, has already become a textbook. The physicist passed a stream of water through a rotating disk with holes. Passing through them, the water heated up. It would seem that the most common transformation of the mechanical energy of the pump engine into heat takes place. But it turned out that 1,6 times more heat was released than electricity was supplied to the engine. Where did the excess energy come from? There are many hypotheses. Here, for example, is one.

When the flow is interrupted, numerous bubbles form in the water. Having existed for thousandths of a second, they begin to shrink and collapse, disappear. This phenomenon is called cavitation.

This process is not simple. If the diameter of the bubble is reduced, for example, by half, then the volume is eight times. The speed of movement of its walls towards each other increases just as quickly. Theoretically, the rate of compression of an absolutely empty bubble can reach the speed of light. True, it usually contains air and water vapor, which can limit the compression rate to hundreds of meters per second. Energy in this case is spent on compressing all the gas in the bubble. But it may happen otherwise.

As the physicist L.V. Larionov, as soon as the walls of the bubble develop supersonic speed, and on them, as if on the nose of a projectile, a very thin shock wave will appear, moving even faster. Then the rate of collapse can be much higher.

The beginning of cavitation was filmed and studied in detail. But with a diameter of 0,001 mm or less, the cavitation bubble can no longer be observed; it is possible to find out what is happening in it only from indirect data.

It is known, for example, that cavitation is capable of destroying any materials. This suggests that very high pressures must be obtained at the end of bubble collapse. Scientists estimate its values from 12 thousand to 450 thousand atmospheres. And at such pressures, the electron shells of atoms and even nuclei can collapse.

It would seem that these processes lead to the appearance of additional thermal energy. But... Practically any nuclear reactions make themselves felt by strong gamma radiation. But it is not observed ... So where does the "extra" energy come from?

Since ancient times, scientists have believed that in the gaps between atoms there is not an absolute void, but some usually unobservable medium - apeiron, or the world ether. Now it is called "physical vacuum". Those who want to get acquainted with the issue in more detail, we refer to the book by I.L. Gerlovin "Fundamentals of a unified theory of interactions in matter", Moscow, 1990. viscosity and, therefore, are not observed at ordinary speeds. But at high speeds, and even in a closed volume of a bubble that is compressed from all sides, its energy can be released in the form of light quanta. If only one atom out of five hundred emits such a quantum, then this will be enough for the appearance of excess heat observed in the experiment.

The liquid in which cavitation occurs glows, which means that these quanta really exist. This glow is called sonoluminescence. Discovered in 1933, it did not find an explanation within the framework of classical science.

But let's move from theory to practice. There are many ways to obtain cavitation. For example, in medical inhalers - devices for obtaining finely sprayed liquid drugs, it is created using ultrasound. But the efficiency of the electronic ultrasonic generator used here is so small that the resulting energy gain is practically not noticeable.

To obtain additional heat, mechanical energy is often used. One of the most powerful installations for this purpose was created by the Omsk inventor V.F. Kladov. He proposed a centrifugal pump, which during its operation creates an intermittent flow of liquid, and when working with water, he received a twofold gain in energy. Experienced Kladov and other liquids. Silicon fluoride, for example, gave a tenfold gain. Other scientists, on the contrary, did not find it with the most careful measurements.

We suggest that you repeat the installation of L. Larionov. It consists of a conventional pumping unit used to supply water to the upper floors of houses. Howl taken a standard unit with a 4 kW motor. A closed circuit of a water pipe is attached to it, into which a cavitation nozzle is inserted and some other elements are added.

When operating on ordinary water, each kilowatt-hour of electricity taken by the pump from the network gave 1,5 kW / h of heat. This effect can be obtained from a home air conditioner operating in heat pump mode. But it costs at least $4000. A water pump is almost a hundred times cheaper.

The main part of the installation is the nozzle. As you can see in the figure, it first narrows and then gradually expands.

Heat from nowhere
Heat generator device: 1 - pumping unit; 2 and 4 - manometers; 3 - nozzle; 5 - static pressure regulator; 6 - throttle valve; 7 - nozzle profile (from the work of German scientists)

Passing through the converging part, the flow, according to Bernoulli's law, increases its speed, and the pressure in it decreases so much that it becomes equal to the pressure of saturated water vapor. When the water boils, it forms a lot of bubbles filled with steam. Next, the flow enters the expanding part of the nozzle. Here, its speed decreases, and the pressure is restored, and the bubbles begin to collapse. This process is completed after exiting the nozzle and is accompanied by sonoluminescence. In the experiment, it is easy to observe it through a special window in the tube. You can see something similar to the torch of a welding torch.

Adding table salt to water enhances this glow. At the same time, heat dissipation also increases significantly. As foreign studies show, the greatest enhancement is achieved when about 120 g of salt is dissolved in a liter of water.

The efficiency of the installation is highly dependent on the shape of the nozzle. When the angle of the flared part is too large, a sharp increase in resistance may occur and efficiency will decrease.

We recommend interesting articles Section Children's Science Lab:

▪ Fountain in the room

▪ Gravitoscope

▪ Lung capacity

See other articles Section Children's Science Lab.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Artificial leather for touch emulation 15.04.2024

In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>

Petgugu Global cat litter 15.04.2024

Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>

The attractiveness of caring men 14.04.2024

The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>

Random news from the Archive

The cup changes the taste of tea 20.09.2023

Researchers from the Nagoya Institute of Technology in Japan have found that the choice of glaze on ceramic tea sets used to brew tea can have a significant impact on the taste of the drink, namely the content of catechin flavonoids.

In their study, the researchers analyzed the effects of four different types of Japanese commercial glazes - Oribe, Namako, Irabo and Tomei - on the levels of catechins, the most abundant flavonoids in green tea.

Glaze coatings, although primarily composed of minerals such as oxides of silicon, aluminum, sodium and calcium, also contain certain metal oxides that give ceramic vessels a unique appearance and texture.

For example, Oribe glaze is rich in copper (Cu) oxides and gives the ceramic a vibrant green color, while Namako glaze contains cobalt (Co) oxides, which create a deep blue hue. Irabo glaze is enriched with iron (Fe) oxides, which give the ceramic an orange tone, while Toumei glaze, on the other hand, contains large amounts of titanium (Ti), which gives the ceramic surface a translucent appearance.

To study the effect of glaze on catechins in tea, the scientists steeped green tea in ionized water at 80°C (176°F) for three minutes. After this, they removed the tea leaves from the liquid and mixed them with glaze powders, which were applied to the ceramics. The tea and glaze mixtures were then allowed to react for six hours, after which the glaze powders were removed by centrifugation and filtration.

Scientists noticed that the pure tea infusion had a bright yellow color, but after six hours of exposure it turned a shade of yellowish brown. In turn, tea infusions treated with different glazes had darker colors - black or brown. In other words, the choice of glaze significantly influenced the color change of the tea.

Moreover, the researchers also found a selective reduction in catechins depending on the type of glaze. This means that green tea brewed in a ceramic pot could turn into black tea.

Scientists have concluded that during the chemical reactions that occur when tea interacts with the glaze, chemical compounds in the glaze contribute to the oxidation of catechin molecules, which can cause the formation of harmful substances for humans. However, this effect does not pose a significant health risk if you do not drink tea from ceramic containers every day and for a long time.

Other interesting news:

▪ Carbon ring

▪ Hearing aid for ornithologist

▪ Graphene will become even more pliable and flexible

▪ New power supplies for LEDs

▪ Single-chip system MT6739

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Biographies of great scientists. Article selection

▪ article Kochubey is rich and famous. Popular expression

▪ article How does scuba gear work? Detailed answer

▪ article Marsh marigold. Legends, cultivation, methods of application