Shock wave - what is it?

2024 Author: Henry Conors | [email protected]. Last modified: 2024-02-12 02:40

Explosion is an instant process of transformation of matter with the simultaneous release of a huge amount of substances with damaging factors. This process is short term. The extent of damage depends on the power of the explosive and the distance from the epicenter of the event.

It is important to know the basic principles of shock wave propagation, its effect on the human body, as well as personal and mass protection equipment.

Varieties of waves

When any substance explodes, a stream of various energies is released. The components of the explosion are:

1. Shock wave. This factor is the most striking, because it produces the destruction of everything that comes in the way. The source of energy is the strong pressure that forms in the center of the explosion. The gases that arise as a result of the reaction rapidly expand and diverge in all directions from the center of the explosion at a tremendous speed (about 2 km / s).
2. Light emission. It is also a wave, since radiant energy,which is released during the explosion, also moves in all directions from the epicenter and negatively affects living organisms.
3. Radiation. The radiation flux consists of various particles. The latter are similar to X-rays, but their speed and quantity negatively affect all living organisms.
4. Electromagnetic pulse. All the given radiations are capable of generating a magnetic field at a low altitude. The impulse is able to disable microprocessor equipment, devices, electricity stations, etc. It is dangerous for people with diseases of the cardiovascular system and mental disorders. EMP is 1% of the power of the ammunition.

Parameters

The characteristic parameters of the shock wave are:

1. Excess pressure. It is the difference between normal atmospheric pressure and the pressure at the wave front. It is because of the formation of pressure that the SW propagates at supersonic speed.
2. Temperature. Light radiation has tremendous power, as a result of which the gases that are released during the explosion heat up. This phenomenon can affect the respiratory system, vision, and in severe cases, cover the area with flames.
3. Alpha, beta and gamma radiation. Together with the above parameters, the nuclei of these particles are rapidly dividing, propagating at a tremendous speed and heating up. High levels of radiation are dangerous, so safety precautions should be taken when encountering these particles.

The impact of the shock wave on the body

Explosion products instantly affect a person: his pressure rises sharply, then the blood vessels of the circulatory system, eardrums rupture. The force of the wave is capable of throwing the body over long distances, as a result of which the body receives additional injuries.

There are several degrees of damage:

1. Easy.
2. Average.
3. Heavy.
4. Especially heavy.

Protection against a nuclear strike

Personal protective equipment and anti-radiation shelters are used to protect against the shock wave of a nuclear explosion. They are able to protect people from dangerous radiation in case of radioactive contamination of the area. In addition, they can protect against light impact, penetrating radiation and, to some extent, from a shock wave, as well as from contact with the skin and human body of all dangerous substances that are released as a result of a nuclear reaction during an explosion.

Safe places are equipped in the basement floors of buildings and various structures. Also, sometimes there are freestanding structures (in the form of industrial buildings or buildings made from improvised materials). Under such shelters, any suitable recesses in the premises are adapted: basements, cellars, underground channels. To increase safety, close up window and extra doorways, pour an additional layer of soil on the floors and, if necessary, make soil bedding at the outer walls that protrude above the ground.

The room is carefully sealed (for example, windows, pipelines, cracks, etc. are glued with improvised materials). The shelters, which can accommodate up to 30 people, are naturally ventilated. Visors are attached to the external ventilation outlets, and tight dampers are attached to the entrances to the room, which are closed for the duration of the action of radiation and the fallout of contaminated precipitation. Inside, the shelter is equipped similarly to ordinary shelters.

In premises that are adapted for shelters, but not equipped with water supply and sewerage, water tanks and a cesspool are installed. In addition, stands, racks, cameras or chests and other provisions for food must be installed in the shelter. Illuminate rooms from a suitable outdoor or portable power supply. The protective properties of an anti-radiation shelter from the effects of an explosion of a shock wave and radiation are estimated by the radiation attenuation coefficient. Its parameter shows how many times the room reduces the external dose of radiation.

Personal protective equipment against blast damage

This is a very important point to consider. During the propagation of the shock wave, exposed areas of the skin, respiratory organs and vision are most at risk. Therefore, these organs should be protected as soon as possible. Primitive defenses include:

• various dressings: gauze, fabric, cotton-gauze, anti-dust, and respirators;
• to protect the skin, insulating andfilter media that reduce the effect of light and nuclear radiation and protect the skin from the effects of alpha particles;
• flame retardant fabrics, light barriers and goggles are also used to protect against light radiation;
• shielding systems are used to protect devices from electromagnetic pulses.

Propagation of the damaging effect of a nuclear wave

Radiation is the damaging factor of a nuclear explosion. This is especially characteristic of explosions that occur in airspace, on the surface of the earth and below it, on a water barrier. The precipitation of soil particles (sand) or water drops during explosions on water bodies and the ground containing dangerous contaminated fragments occurs within a couple of minutes after the start of the explosion and lasts up to 2 days. The cloud forms a characteristic ground trail as it travels.

The damaging effect of radioactive decay products of a nuclear explosion on a living organism is usually divided into 2 periods: the formation of a trace occurs immediately after particles fall out of a moving cloud of a nuclear explosion, and the period of the formed trace, when the contaminated precipitation has already fallen to the ground.

What happens during the collision of a wave and an object

The damaging factors of the shock wave apply to people and animals, as well as to buildings, structures and the environment. This happens due to the impact of strong overpressure in a short period of time. The shock wave in a fraction of a second completely covers the object and exposesits strong compression. Such a factor is perceived by the body as a powerful and sharp blow, and the air pressure moves the body over a long distance. The degree of impact depends on the nature of the wave formation: the power of the explosion, distance, weather conditions and even location.

Consequences

What are the consequences of the shock wave? This issue should be given special attention. A shock wave pressure of up to 10 kPa in open areas is considered acceptable. Anything above the limit is harmful to humans and animals:

• At a pressure of 20 to 40 kPa, slight damage to the body occurs. The latter are characterized by minor disturbances. Such symptoms soon disappear without medical intervention. Characteristic signs of a mild lesion are: headache, dislocations and minor bruises, ringing in the ears, etc.
• At a pressure of 40 to 60 kPa, hearing, vision, contusion, hemorrhage from the nasal passage and ears are possible.
• If the pressure exceeds 60 kPa, severe damage occurs. Characteristic signs are: contusion of the whole organism, damage to internal organs, internal hemorrhage. In severe cases, it can be fatal.
• Very severe injuries occur when pressure exceeds 100 kPa. With such exposure, severe fractures, ruptures of organs, loss of consciousness for a long time are noted.

During the destruction of buildings and structures, the fragments are able to move over distances that exceed the radius of actionwaves.

Shock wave factors also have a negative effect on plants. At a pressure of 50 kPa and above, the green massif is completely damaged. At the same time, mature trees are uprooted. If the pressure is from 30 to 50 kPa, then up to half of the green cover is damaged, and if it is from 10 to 30 kPa, up to 30% of all trees are destroyed. A feature is the resistance of trees - young seedlings are more resistant to wave action.

What can be done

Let's consider methods of protection against a shock wave. To protect themselves from radiation exposure, various protective structures are used: shelters, basements, stations. At the same time, all rooms must have a high coefficient of protective action. You should also take radioprotective drugs.

The following types of protective structures are distinguished:

1. Shelters. Designed to shelter people from all damaging factors: toxic substances, bacterial agents, critical temperatures, hazardous gases and radiation. Such rooms should be equipped with a protective airtight door, vestibules, a main room, a pantry for products, a medical room, an emergency exit and a ventilation chamber.
2. The most primitive shelters include open and closed gaps. They are built by the population using any materials at hand. Primitive shelters can reduce the effect of penetrating radiation and radiation by 200-300 times.

Compliance with security measures and an evacuation plan significantly increases the chances ofpreservation of human life and he alth.