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Capillary Pressure Calculator
Calculate capillary pressure using the Young-Laplace equation
Input Parameters
Default: 0.072 N/m (water at 20°C)
0° = perfect wetting, 90° = non-wetting
Capillary Pressure
Pressure (Pa)
2880.00
Pressure (mbar)
28.800
Pressure (psi)
0.4177
About Capillary Pressure
Capillary pressure is the pressure difference across a curved interface between two immiscible fluids, described by the Young-Laplace equation.
For circular channels: ΔP = 2γcosθ/r
For rectangular channels: ΔP = 2γcosθ(1/w + 1/h)
When it matters:
- • Droplet generation and formation in microfluidic devices
- • Two-phase flow behavior in confined geometries
- • Spontaneous imbibition and fluid injection
- • Channel wetting and surface coating design
- • Emulsion stability in microfluidic systems
A higher capillary pressure makes it harder to inject a non-wetting phase into a channel but can stabilize droplets once formed.
Disclaimer: This calculator assumes ideal channel geometry and a static contact angle. Actual capillary pressure may vary due to surface roughness, dynamic contact angle effects, surfactant concentration, and non-uniform channel cross-sections. Always validate with experimental measurements.