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The Coefficient of Permeability from Analogy of Laminar Flow (Hagen-Poiseuille flow) estimates the hydraulic conductivity of porous media by drawing an analogy to laminar flow through circular pipes. It reflects the combined effect of porous medium and fluid properties on flow characteristics.
The calculator uses the Hagen-Poiseuille equation:
Where:
Explanation: The equation accounts for the geometric properties of the porous medium and the physical properties of the fluid to determine permeability.
Details: Accurate permeability estimation is crucial for groundwater flow analysis, contaminant transport studies, geotechnical engineering, and petroleum reservoir characterization.
Tips: Enter shape factor (dimensionless), mean particle size in meters, unit weight of fluid in N/m³, and dynamic viscosity in Pa·s. All values must be positive and valid.
Q1: What is the typical range of permeability values?
A: Permeability values range from 10⁻¹² m/s for clay to 10⁻¹ m/s for gravel, depending on the porous medium characteristics.
Q2: How does particle size affect permeability?
A: Permeability increases with the square of mean particle size, making it highly sensitive to changes in grain size distribution.
Q3: What factors influence the shape factor?
A: The shape factor depends on porosity, packing arrangement, grain shape, and grain-size distribution of the porous medium.
Q4: When is the Hagen-Poiseuille analogy applicable?
A: This analogy is most applicable for laminar flow conditions through porous media with relatively uniform particle sizes.
Q5: How does fluid viscosity affect permeability?
A: Permeability is inversely proportional to dynamic viscosity - more viscous fluids result in lower permeability values.