Search results
Results from the WOW.Com Content Network
In gliding, wind gradient affects the takeoff and landing phases of flight of a glider. Wind gradient can have a noticeable effect on ground launches. If the wind gradient is significant or sudden, or both, and the pilot maintains the same pitch attitude, the indicated airspeed will increase, possibly exceeding the maximum ground launch tow speed.
Wind gradient can have a noticeable effect on ground launches, also known as winch launches or wire launches. If the wind gradient is significant or sudden, or both, and the pilot maintains the same pitch attitude, the indicated airspeed will increase, possibly exceeding the maximum ground launch tow speed. The pilot must adjust the airspeed to ...
The equation to estimate the mean wind speed at height (meters) above the ground is: = [ + (,,)] where is the friction velocity (m s −1), is the Von Kármán constant (~0.41), is the zero plane displacement (in metres), is the surface roughness (in meters), and is a stability term where is the Obukhov length from Monin-Obukhov similarity theory.
Typically, due to aerodynamic drag, there is a wind gradient in the wind flow ~100 meters above the Earth's surface—the surface layer of the planetary boundary layer. Wind speed increases with increasing height above the ground, starting from zero [4] due to the no-slip condition. [5]
The 45 WS provides comprehensive weather data and specialized services for Space Force and NASA personnel, such as for flight safety, resource protection (i.e. ground building and equipment), pre-launch ground processing, day-of-launch for Shuttle and other rockets, post-launch, aviation, and special operations.
The wind profile of the atmospheric boundary layer (surface to around 2000 metres) is generally logarithmic in nature and is best approximated using the log wind profile equation that accounts for surface roughness and atmospheric stability. The relationships between surface power and wind are often used as an alternative to logarithmic wind ...
Wind gradient can have a noticeable effect on ground launches, also known as winch launches or wire launches. If the wind gradient is significant or sudden, or both, and the pilot maintains the same pitch attitude, the indicated airspeed will increase, possibly exceeding the maximum ground launch tow speed.
Roughness length is a parameter used in modeling the horizontal mean wind speed near the ground. In wind vertical profile such the log wind profile, the roughness length (with dimension of length and SI unit of metres) is equivalent to the height at which the wind speed theoretically becomes zero in the absence of wind-slowing obstacles and ...