*-x 



♦-X 



♦-X 



Fig, 11. Streamlines of the air over a wavy s\irface, 



and distribution of wind force components 



7" and Z"^ in schematic representation, 

 n u 



7 = a sinX(x - (Tt), (1) 



where a is the wave amplitude, 36= 2-w/x, the wave number and <r the 

 velocity of wave propagation (phase velocity). The horizontal com- 

 ponent of the displacement of a water particle at the surface is 



^ = a cos3C(x - crt) . (2) 



With these expressions, we have the vertical (w^) and horizontal 



(u ) component of partical velocity as given by 



Wq = dy/dt = - a ae.<r cos ae (x - <rt). 



(3) 



and 



Uq = d^ /dt = a-aecsinX-Cx - (rt) . 



(4) 



49 



