Hazen-Williams vs. Darcy-Weisbach Contrast Engine

Evaluate pressure drops side-by-side to compare empirical water approximations against rigorous fluid mechanics models.

Governing Hydraulic Formulas:

Darcy-Weisbach (Universal): $ h_f = f \times \frac{L}{D} \times \frac{V^2}{2g} $

Hazen-Williams (Water Only): $ h_f = 0.2083 \times \left(\frac{100}{C}\right)^{1.852} \times \frac{Q^{1.852}}{d^{4.8655}} \times \frac{L}{100} $

Common Pipeline Inputs

Pipe Inner Diameter (Inches)

Flow Rate (GPM)

Pipeline Length (Feet)

Hazen-Williams Roughness (C-Factor)

Darcy Pipe Roughness ($\epsilon$ in mm) Default: Smooth Commercial PVC ($\epsilon = 0.0015 \text{ mm}$)

Hazen-Williams Head Loss 22.84 Feet 9.90 PSI Loss

Darcy-Weisbach Head Loss 21.95 Feet 9.52 PSI Loss

Model Divergence Index 3.89% Difference

Hazen-Williams and Darcy-Weisbach models show high correlation (under 5% variance) at standard room temperature water flow velocities.