It is well known that the simplest, and therefore probably widespread in nature phenomenon exhibiting energy exchange is the heating of bodies during friction. These processes surround us almost everywhere. Heat transfer is present during mechanical, chemical, electrical, biological and other dynamic changes. Heat transfer plays a huge role in the existence of organic life. Already from this variety of manifestations, a logical conclusion follows that these phenomena can be both useful and harmful, depending on what problem the researcher or inventor solves. That is, in some cases it is necessary to get rid of heat transfer in order to create the necessary conditions for the operation of any device, device or unit.
The adiabatic process, which is a kind of thermodynamic process in which there is no exchange of heat energy of the system in question with the environment, solves these problems. The very name of this phenomenon, translated from Greek, speaks of its nature - adiabatic or, as it is also called, adiabatic means "impassable."
Even ancient scholars were interested in these phenomena, but a truly scientific study of their nature dates back to the 17th century, when the first theoretical positions were formulated based on experimental work. Among the first scientists who studied the adiabatic process, it is worth mentioning Guericke, Robert Boyle, Edm Mariott. The last two became the first theorists in this field, formulating the well-known Boyle-Mariotte law. The first experimental work in this area was carried out on gases; therefore, a significant part of the laws that characterize the adiabatic process relate specifically to this physical medium. Later, the scope of research was significantly expanded, and today adiabatic phenomena are studied in a variety of environments, including at the level of nanotechnology.
The adiabatic process under consideration has the following nature and mechanism of its manifestation. If the presence of heat exchange, which is obtained as a result of various dynamic interactions with the surrounding space, is characteristic of ordinary thermodynamic phenomena, then in this case this exchange does not occur.
There is a way to mathematically reflect the adiabatic process, the formulas, which in this case will vary depending on the variety of the process itself.
The general formula reflecting this phenomenon has the form: A = -VU, where A is the work that this physical system performs, VU is the amount of change in its internal energy.
There are several types of adiabatic processes:
- adiabatic-isochoric occurs with a single exposure, as a result of which only the volume of the mixture (V) remains unchanged from thermal indicators. Work (A), as can be seen from the formula, in this case will be zero;
- adiabatic-isobaric is characterized by compression of the test gas mixture, that is, its volume decreases, and the work value becomes negative;
- adiabatic-isothermal has inverse properties in relation to the previous one and is characterized by an increase in volume (i.e., expansion of the body), while the value of the work becomes positive.
Examples of adiabatic processes that are realized in various natural phenomena, as well as in mechanisms and devices created by man, can be given. So, their presence is observed during the propagation of sound in a gas. And the Earth’s atmosphere itself is an adiabatic macroprocess, during which some work is done on the gases that make it up, increasing their potential energy. This theory is now extended to other astronomical objects.
The processes under consideration are present in all thermal machines and mechanisms without exception: steam locomotives, diesel locomotives, internal combustion engines and others, where it is necessary to exclude the transfer of heat energy.