An extended Miles' theory for wave generation by wind

✍ Scribed by D. S. Riley; M. A. Donelan; W. H. Hui

• Book ID: 104627883
• Publisher: Springer
• Year: 1982
• Tongue: English
• Weight: 934 KB
• Volume: 22
• Category: Article
• ISSN: 0006-8314
• DOI: 10.1007/bf00118254

✦ Synopsis

Miles' inviscid theory of surface wave generation by wind is (a) modified by replacing the logarithmic shear velocity proiile with one which applies right down to the wave surface and which exhibits an explicit dependence on the roughness of the surface, and (b) extended to include the effects of the interaction of wave with air flow turbulence by considering the wave-modified mean flow as the mean of the actual turbulent air flow over water waves and using this in a mixing-length model.

The surface pressure is shown to depend significantly on the flow conditions being aerodynamically smooth or rough. Its component in phase with the surface elevation is practically unaffected by the wave-turbulence interaction. However, such interaction tends to increase the rate of energy input j from wind to waves travelling in the same direction, e.g., the increase is 2~' for aerodynamically rough flow, where K is the Von Karman constant. It also provides damping of waves in an adverse wind which can be about 10% of the growth rate in a favourable wind.