Page 313 - Теория кавитации

Control unit and control units 1 Remote control
(on/off), temperature
control (thermostat)

Linear flow rate, m/s 0,25

Concept VHG installation is quite simple and has a characteristic common construct basic nodes which
consist of casing pipes, swirl, snails (Figure 1).

Figure 1 - Schematic diagram of VHG.

In Figure 1, the arrows show the direction of fluid flow after exiting the high-pressure pumping device
(PD) into the nozzle, which narrows and is directly attached to the swirler. If the swirler is connected to a pipe
of the appropriate diameter, then the flow of the liquid will continue along the pipe with intensive rotation around
its axis. Since the jet of liquid due to centrifugal rotational forces is broken when a vortex is formed, a reduced
pressure inside the vortex itself causes the fluid in contact with it to “boil” intensively, i.e. there is a continuous
process of formation of cavitation bubbles along the entire inner surface of the contact of the vortex with a
column of liquid.
Further, the formed microscopic (about 0.5-3.0 microns in size) bubbles saturate the liquid and are carried
away by the flow by mixing, and new ones are continuously formed in their place. The surface tension force in
2
such bubbles reaches a value of 104 kg/cm . When the whole mass of a liquid is saturated with bubbles, it
accumulates energy, which, when the bubbles collapse, is converted into thermal energy, heating the liquid [13]-
[15].
At the same time, the rotation leads (at the molecular, atomic and other levels) to the appearance of
additional bonds between the micro particles of the liquid, and the intense release of energy in the form of heat.
This process occurs when there is acceleration of particles of a moving fluid. This is the essence and principles
of work of computer technology.
We give a description and characteristics of the main components of the elemental blocks used in the
development of this VHG.

Vortex pipe:
The vortex tube (or simply, the tube) is one of the key elements of the VHGD. All the main physical and
chemical processes of thermal energy generation take place in it, with swirling (vortex) movement of high-
pressure fluid flow, the appearance and collapse of bubbles (cavitation effect), etc.
The main technological parameters of the pipe used that developed by VHG are shown in Table 1. We chose a
material - plexiglass (Figure 2) as the material of the pipes, for clarity and demonstration of swirling (vortex)
flows. In addition to the specified quality, the choice of plexiglass as a material of a vortex tube in the developed
stand VHG is related to its better physicochemical properties, in particular:
 Glossy surface;
 High light transmittance;
 Unique resistance to aging and temperature conditions;
 High impact resistance;
 High corrosion resistance, etc.
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