Porosity and Permeability Calculator
Calculate porosity and permeability of porous materials using Darcy's law
Calculate Porosity and Permeability
Pressure at the fluid entrance
Pressure at the fluid exit
Distance fluid travels through the material
Cross-sectional area of the material
Volumetric flow rate of fluid
Dynamic viscosity of the fluid
Time for fluid to travel through the material
Calculation Results
Permeability (k)
Darcy's law (permeability): k = (Q × μ × L) / (A × Δp)
Porosity equation: φ = (Q × t) / (A × L)
Pressure difference: 0 Pa
Material Analysis
Example Calculation
Sandstone Core Sample
Fluid: Water (μ = 0.001 Pa⋅s)
Core diameter: 2.5 cm (Area = 4.91 cm²)
Core length: 5 cm
Pressure difference: 1000 Pa
Discharge rate: 0.5 cm³/s
Calculation
k = (Q × μ × L) / (A × Δp)
k = (0.5×10⁻⁶ × 0.001 × 0.05) / (4.91×10⁻⁴ × 1000)
k = 2.5×10⁻¹¹ / 0.491
k = 5.09×10⁻¹¹ m² = 51.6 millidarcy
Typical Permeability Values
Applications
Hydrogeology and groundwater flow modeling
Petroleum reservoir characterization
Geotechnical engineering and soil analysis
Materials science and filtration design
Environmental remediation studies
Understanding Porosity and Permeability
What is Permeability?
Permeability is a measure of how easily a fluid can flow through a porous material. It quantifies the ability of a material to transmit fluids under a pressure gradient. Higher permeability means better fluid flow characteristics.
What is Porosity?
Porosity is the fraction of void space in a material relative to its total volume. It represents how much empty space exists within the material structure. However, high porosity doesn't always mean high permeability if the pores are not interconnected.
Darcy's Law
Q = (k × A × Δp) / (μ × L)
k = (Q × μ × L) / (A × Δp)
- Q: Discharge rate (m³/s)
- k: Permeability (m² or darcy)
- A: Cross-sectional area (m²)
- Δp: Pressure difference (Pa)
- μ: Dynamic viscosity (Pa⋅s)
- L: Flow distance (m)
Note: 1 darcy = 9.87×10⁻¹³ m². The darcy unit is commonly used in petroleum engineering and hydrogeology.