Directional Slope and Curvature Distributions of Wind Waves
HYDRONAUTICS INC LAUREL MD
Pagination or Media Count:
The slope and curvature distributions of wind waves along two principal axes upwind-downwind and crosswind have been measured in a laboratory tank under various wind velocities. In both directions, the slope distributions are very closely Gaussian, and the components of the mean-square water-surface slope vary logarithmically with the friction velocity of the wind. As the wind velocity increases, the ratio between these two components increases and falls between 0.5 and 0.6 at high wind velocities in the gravity-governing regime of wind-wave interaction. The radius of water-surface curvature, along either direction of measurement, is found to be, generally, greater at a steeper viewing angle from the normal to the mean water surface. The average radius of curvature of the disturbed surface varies inversely with the friction velocity of the wind. The ratio between the upwind-downwind and crosswind components of the average radius of curvature is unity at all wind velocities, indicating that the wind-disturbed water surface is isotropic on the smallest scale.
- Physical and Dynamic Oceanography