1. What is the Rate of Flow Formula?

The rate of flow formula calculates discharge through porous media using Darcy's law. It determines the volume of fluid passing through a cross-sectional area per unit time based on the coefficient of permeability, hydraulic gradient, and cross-sectional area.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Discharge (m³/s)
• \( K_w \) — Coefficient of permeability (m/s)
• \( i_e \) — Hydraulic gradient (unitless)
• \( A_{xsec} \) — Area of cross section (m²)

Explanation: The formula calculates the volumetric flow rate through porous media by multiplying the permeability coefficient, hydraulic gradient, and cross-sectional area.

3. Importance of Discharge Calculation

Details: Accurate discharge calculation is crucial for groundwater flow analysis, seepage studies, foundation design, and environmental engineering applications involving fluid flow through soils and porous media.

4. Using the Calculator

Tips: Enter coefficient of permeability in m/s, hydraulic gradient (unitless), and cross-sectional area in m². All values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What is the coefficient of permeability?
A: The coefficient of permeability (K_w) represents the ease with which water can flow through porous media, measured in meters per second.

Q2: How is hydraulic gradient determined?
A: Hydraulic gradient (i_e) is calculated as the difference in hydraulic head divided by the flow path length between two points.

Q3: What factors affect the coefficient of permeability?
A: Soil type, grain size distribution, porosity, density, and degree of saturation all influence the permeability coefficient.

Q4: When is this formula applicable?
A: This formula applies to laminar flow through saturated porous media where Darcy's law is valid.

Q5: What are typical values for coefficient of permeability?
A: Values range from 10^-2 m/s for gravel to 10^-9 m/s for clay, depending on soil characteristics.