Wind Velocity Prediction Guide
Wind changes with height, terrain, air density, and pressure. A simple speed value is rarely enough. This calculator lets you compare several prediction equations in one place. It is useful for site planning, ventilation checks, turbine studies, drone review, and structural screening.
Why Wind Velocity Changes
Wind near the ground is slowed by friction. Trees, buildings, hills, and rough surfaces create drag. Smooth land allows wind to grow faster with height. Dense air also changes wind pressure. A cold day with dense air can create stronger force than a warm day at the same speed.
Main Prediction Methods
The power law is fast and widely used. It uses a shear exponent named alpha. Low alpha values fit smooth terrain. Higher values fit cities and wooded sites. The logarithmic law uses roughness length. It is more terrain focused. The pressure equation estimates velocity from pressure difference. It follows the energy relation between moving air and dynamic pressure.
Using More Than One Equation
A single equation may not match every site. The blended method averages valid methods. It is helpful for early planning. It should not replace field measurements. It gives a balanced estimate when inputs are uncertain. Engineers can compare the power result, log result, and pressure result before selecting a design value.
Planning With Results
The final result includes mean speed, gust speed, design speed, dynamic pressure, and wind power density. Mean speed is useful for airflow studies. Gust speed is useful for peak events. Design speed adds a safety factor. Dynamic pressure shows the force trend. Wind power density helps energy checks.
Better Input Practices
Use measured wind speed from a trusted station. Match the reference height with the station height. Choose terrain carefully. Do not enter a roughness length greater than either height. Use local air density when possible. Sea level standard density is 1.225 kg/m³, but altitude and temperature can change it.
Limitations
This tool gives an engineering estimate. Real wind is turbulent and directional. Local obstacles can create sudden speed changes. For permits, towers, bridges, or public safety decisions, use certified local codes and professional review and documented site wind notes.