Favre and Coantio 



J = 0,87 



u:=v^ 



0,001 Opa2 Cf05 Opi 0,02 Qj05 0,1 q2 



VS" 



c\oi qp2 0,05 o; q2 



"0" 



X= 3640 



16 Y=0 



X=5750 4=157 



Y=0 



e = 15 mm 



Fig. 14. Effects of blowing on turbulence Intensity distributions. 



3. Hydraulic Tests 



The hydraulic perfornnance of the facility has also been sub- 

 jected to various tests. The functioning of the water recirculating 

 circuit has been controlled. The working of the new submerged 

 wavemaker, and of the absorbing beach, has also been found satis- 

 factory. 



Observations of waves generated by wind in the tnodel tank, 

 such as those shown by Fig. 15, suggests they qualitatively possess 

 the three-dimensional random structure typical of oceanic wind 

 waves. Measurements of wave spectrum at different fetches along 

 the working section have just been done, and the results displayed 

 in Fig. 16 compare favorably with those of previous studies (see 

 the references in III. 4). The spectral shape and evolution strongly 

 suggests the existence of nonlinear effects transferring energy from 

 higher to smaller frequencies , as recently postulated by Longuet- 

 Higgins and Mollo-Christensen. 



56 



