Environment Climate Meterology

Overview

Engineering reference data for Environment Climate Meterology in material science and properties.

Key Formulas

Stress

$\sigma = \frac{F}{A}$

Force per unit area.

Strain

$\varepsilon = \frac{\Delta L}{L_0}$

Change in length per original length.

Hooke's Law

$\sigma = E \varepsilon$

Stress proportional to strain in elastic region.

Thermal Expansion

$\Delta L = \alpha L_0 \Delta T$

Length change due to temperature.

Variables

Environmental Engineering Reference

Wind Energy Fundamentals

The kinetic energy available in wind is given by:

$P = \frac{1}{2} \rho A v^3$

where $P$ is power (W), $\rho$ is air density (kg/m³), $A$ is the swept area (m²), and $v$ is wind speed (m/s).

For a circular turbine rotor: $A = \pi r^2$

Wind Chill Index

The North American Wind Chill Index (2001) formula:

$T_{wc} = 13.12 + 0.6215T_a - 11.37v^{0.16} + 0.3965T_a v^{0.16}$

where $T_{wc}$ is the wind chill temperature (°C), $T_a$ is the air temperature (°C), and $v$ is the wind speed at 10 m height (km/h).

Hydropower

The theoretical power available from hydropower:

$P = \rho g Q H$

where $P$ is power (W), $\rho$ is water density (≈1000 kg/m³), $g$ is gravitational acceleration (9.81 m/s²), $Q$ is flow rate (m³/s), and $H$ is head (m).

Accounting for efficiency:

$P_{actual} = \eta \rho g Q H$

where $\eta$ is the overall efficiency (typically 0.7–0.9).

Solar Energy

Daily solar energy on a surface:

$E = \int_0^T I(t) \, dt$

where $I(t)$ is the solar irradiance (W/m²) as a function of time.

Solar heat gain through glazing:

$Q_{solar} = A \cdot SHGC \cdot I$

where $SHGC$ is the Solar Heat Gain Coefficient (dimensionless, 0–1) and $I$ is incident solar radiation (W/m²).

Degree-Day Calculations

Heating Degree-Days (HDD):

$HDD = \sum_{i=1}^{n} \max(T_{base} - T_{avg,i}, \, 0)$

Cooling Degree-Days (CDD):

$CDD = \sum_{i=1}^{n} \max(T_{avg,i} - T_{base}, \, 0)$

where $T_{base}$ is the base temperature (commonly 18°C / 65°F) and $T_{avg,i}$ is the daily average temperature.

Salinity Classifications

References

• Original Source