Void Fraction (Volume) formula |
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| \( \epsilon \;=\; \dfrac{ v_g }{ v_g + v_i } \) | ||
| Symbol | English | Metric |
| \( \epsilon \) (Greek symbol epsilon) = Void Fraction | \(dimensionless\) | \(dimensionless\) |
| \( v_g \) = Volume of Gas Phase or Vapor Phase | \(in^3\) | \(mm^3\) |
| \( v_l \) = Volume of Liquid Phase (Total Volume of Mixture) | \(in^3\) | \(mm^3\) |
Void fraction, abbreviated as \( \epsilon \) (Greek symbol epsilon), a dimensionless number, measures the proportion of void space or empty volume within a material or a flow. It is used in science and engineering, particularly in multiphase flows where different phases (like gas and liquid) exist together. In such systems, void fraction is defined as the ratio of the volume occupied by the gas phase to the total volume of the flow channel. For example, if a pipe contains a mixture of water and air, the void fraction would be the percentage of the pipe's volume taken up by air.
Void Fraction (Area) formula |
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| \( \epsilon \;=\; \dfrac{ A_g }{ A_g + A_i } \) | ||
| Symbol | English | Metric |
| \( \epsilon \) (Greek symbol epsilon) = Void Fraction | \(dimensionless\) | \(dimensionless\) |
| \( A_g \) = Area Cross-section Occupied by Gas | \(in^2\) | \(mm^2\) |
| \( A_l \) = Area Cross-section Occupied by Liquid | \(in^2\) | \(mm^2\) |