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MMM      SEMINAR      NCAR


 

 Direct Numerical Simulation

of Wind Waves Generation Processes

 

Mei-Ying Lin

National Chung-Tung University

Civil Engineering Department

Taiwan

 

 


We develop an air-water coupled direct numerical simulation model to investigate the initial wave growing process at air-water interface.  The coupled model satisfies the continuities of velocity and stress simultaneously at the interface and hence captures the interaction of air and water motions and wave growth processes.  The results show that the wavelength of fastest growing waves agrees with laboratory measurements and the flow fields reveal very different characteristics during the turbulence-dominated and the wave-dominated stages.

 

In this presentation, we will show the animation of wave growth.  We will examine the pressure fields in both air and water for wave growth mechanism.  Comparing the wave growth mechanism to previous theoretical works, we will show that it agrees with Belcher & Hunt’s (1993) theory that proposes the feedback mechanism between waves and pressure fluctuations in the air for exponential wave growth.  Sensitivity tests of the effect of turbulence in the water and of the surface tension show no significant influence on wave growth process.

 

 

PLEASE NOTE LOCATION

 

 

Thursday, 22 June 2006, 3:30 PM

Refreshments 3:15 PM

NCAR-Foothills Laboratory

3450 Mitchell Lane

Bldg 2, Rm. 1001