Air-Sea Intevaotions ; Program at IMST 



SECTION A 



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SECTION B 



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Fig. 6. General scheme of the wind-water tunnel 



3. Reproduction of Heat and Mass Transfer Processes 



Supposing a convenient flow structure has been obtained, the 

 existence of nonzero temperature and partial water vapor pressure 

 differences between the water surface and the incoming air flow will 

 be sufficient to cause turbulent convective processes of mass and 

 sensible and latent enthalpy similar to those encountered in the 

 atmospheric boundary layer. 



The equations governing these transfers being linear with 

 respect to"temperature and humidity, these last variables can be 

 fixed on grounds of experimental convenience, as long as stratifi- 

 cation effects do not arise. The estimated values of flux Richardson 

 number, computed at one-quarter boundary layer thickness and for 

 a temperture difference amounting to 25 °C, are displayed in Fig. 

 2(d) as a function of longitudinal abscissa and velocity. At the 

 highest velocities , Richardson number is clearly negligible , and 

 temperature and humidity differences will be chosen, to improve 

 experimental accuracy, at the highest levels authorized by the 

 equipment's capabilities (see Fig. 2(b), and below). On the other 

 hand, at the lowest velocities, temperature and humidity can no 

 longer be considered as scalar passive contaminants, and their 

 differences will be chosen in order to obtain a given Richardson 

 number, i.e. a given effect on the dynamical structure. 



47 



