Soil Water Content

Reference data and engineering information about soil water content for combustion applications.

soilwatercontent

Overview

Engineering reference data for Soil Water Content in combustion engineering.

Key Formulas

Heat Release

$Q = \dot{m} \cdot HV$

Fuel energy release rate.

Air-Fuel Ratio

$AF = \frac{m_{air}}{m_{fuel}}$

Mass of air per mass of fuel.

Excess Air

$EA = \frac{O_2}{21 - O_2} \times 100\%$

From flue gas oxygen measurement.

Variables

Symbol	Description	Unit
$Q$	Heat release rate	W
$\dot{m}$	Mass flow rate	kg/s
$HV$	Heating value	J/kg
$AF$	Air-fuel ratio	—

The soil water content can be determined using the oven-drying method as per ASTM D 2216-92. This involves measuring the mass of a wet soil specimen, then drying it in an oven at a temperature of $110^\circ\text{C}$ for 12 to 16 hours. The water content is calculated using the formula:

$w = 100 \frac{M_w}{M_s}$

where:

$w$ is the moisture content (%),
$M_w$ is the mass of water in the soil (kg or lb),
$M_s$ is the dry mass of the soil (kg or lb).

Typical Values

Soil water content varies widely depending on the soil type. Values can range from essentially 0% for near-surface rubble, gravel, or clean sand, up to 1200% for organic soils like fibrous peat.

References

Original Source

Source: engineeringtoolbox.com