METEOROLOGY – WIND CALCULATOR
Wind Profile Power Law
A precise tool.
What is the Wind Profile Power Law & How does it work?
The wind speed profile in the atmospheric boundary layer can be described using the power law, which is particularly useful for understanding how wind speed varies with height above the ground.
u(z) = u_0 left(frac{z}{z_0}right)^{alpha}
u(z) = wind speed at height z
u_0 = reference wind speed
z = height above ground
z_0 = roughness length
alpha = Hellmann exponent (usually between 0.1 and 0.2)
u_0 = reference wind speed
z = height above ground
z_0 = roughness length
alpha = Hellmann exponent (usually between 0.1 and 0.2)
The Hellmann exponent, (alpha), is a dimensionless parameter that depends on the surface characteristics and the stability of the atmosphere. It plays a crucial role in determining how wind speed increases with height.
Parameters
Result
β
Frequently Asked Questions
What is the wind profile power law?
The wind profile power law describes how wind speed varies with height above the ground in the atmospheric boundary layer.
How do I use the Hellmann exponent in this calculator?
The Hellmann exponent (Ξ±) is a dimensionless parameter between 0.1 and 0.2 that depends on surface characteristics and affects wind speed variation with height.
What does the roughness length represent?
Roughness length (zβ) represents the height of the virtual obstacles near the ground that affect wind flow, such as trees or buildings.
How do I interpret the reference wind speed (uβ)?
The reference wind speed (uβ) is the wind speed at a standard height above the ground, typically used to calculate wind speeds at other heights.
Can this calculator be used for any terrain?
This calculator is suitable for various terrains but assumes a stable atmospheric boundary layer. For complex terrains, additional factors may need consideration.
What are the limitations of using the power law in wind profile calculations?
The power law is most accurate near the ground and becomes less reliable with increasing height or under unstable atmospheric conditions.
How does this calculator help in renewable energy applications?
This calculator aids in estimating wind speeds at different heights, which is crucial for siting wind turbines and optimizing their performance.
Results are for informational purposes only and do not constitute professional advice.