Concept of Liquid cavitation:
Cavities in the liquid body is the result of partial vaporization of liquid. Although the term cavitation can
mean the formation of cavities of gas or vapor in a liquid, the cavitation process consists of both liquid cavity formation, and liquid cavity deformation. It is therefore a reversible, double change of state phenomenon. On the hand the terms boiling and flashing are special categories of vaporization. Boiling is defined as the specific vaporization point of a liquid in the presence of local atmospheric pressure .
Flashing involves a fluid’s rapid phase change from liquid to vapor without the return of the fluid to the liquid phase.
One should not mean that cavitation, boiling,and flashing all are the same thing and therefore can be used interchangeably.
There are also occurrences in which relative flow arrangement, entrainment/dissolution, or chemical reaction can lead to cavity formation and later collapse in what is known as pseudo-cavitation. Liquids exposed to air or other gases can absorb a portion of that gas. Liquids often therefore become a solution of the parent liquid and a dissolved gas, with a different vapor pressure from that of the pure liquid. The mixture of liquid and vapor is now a compressible fluid. When pressure increases, the mixture passes through its vapor pressure level and the vapor pockets instantly collapse like tiny balloons. Dissolved air or gases coming out of solution and imploding has been referred to as pseudo-cavitation.
It is general belief that Cavitation is always problematic and detrimental and therefore always should be eliminated or at least minimized. This belief is absolutely correct in perspective of process equipments of process industry. But there are some application such as subsurface drilling operation or process mixing applications where the associated turbulence is advantageous. A recent development in mixing micro technology called cavitation micro streaming, whereby a gas bubble inside a liquid is made to oscillate at a various frequencies, greatly enhances the mixing of blood samples with reagents.
The process of cavitation begins when the pressure on portions of the liquid decrease to a point low
enough for the fluid to change states, from a liquid to a gas. This occurs at the vapor pressure of the
liquid.
Cavities in the liquid body is the result of partial vaporization of liquid. Although the term cavitation can
mean the formation of cavities of gas or vapor in a liquid, the cavitation process consists of both liquid cavity formation, and liquid cavity deformation. It is therefore a reversible, double change of state phenomenon. On the hand the terms boiling and flashing are special categories of vaporization. Boiling is defined as the specific vaporization point of a liquid in the presence of local atmospheric pressure .
Flashing involves a fluid’s rapid phase change from liquid to vapor without the return of the fluid to the liquid phase.
One should not mean that cavitation, boiling,and flashing all are the same thing and therefore can be used interchangeably.
There are also occurrences in which relative flow arrangement, entrainment/dissolution, or chemical reaction can lead to cavity formation and later collapse in what is known as pseudo-cavitation. Liquids exposed to air or other gases can absorb a portion of that gas. Liquids often therefore become a solution of the parent liquid and a dissolved gas, with a different vapor pressure from that of the pure liquid. The mixture of liquid and vapor is now a compressible fluid. When pressure increases, the mixture passes through its vapor pressure level and the vapor pockets instantly collapse like tiny balloons. Dissolved air or gases coming out of solution and imploding has been referred to as pseudo-cavitation.
It is general belief that Cavitation is always problematic and detrimental and therefore always should be eliminated or at least minimized. This belief is absolutely correct in perspective of process equipments of process industry. But there are some application such as subsurface drilling operation or process mixing applications where the associated turbulence is advantageous. A recent development in mixing micro technology called cavitation micro streaming, whereby a gas bubble inside a liquid is made to oscillate at a various frequencies, greatly enhances the mixing of blood samples with reagents.
The process of cavitation begins when the pressure on portions of the liquid decrease to a point low
enough for the fluid to change states, from a liquid to a gas. This occurs at the vapor pressure of the
liquid.
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