On the generation of waves by turbulent wind

摘要: A theory is initiated for the generation of waves upon a water surface, originally at rest, by random distribution normal pressure associated with onset turbulent wind. Corrlations between air and motions are neglected assumed to be inviscid, so that motion water, starting from irrotational. It found develop most rapidly means resonance mechanism which occurs when component surface moves same speed as free wave wave-number.The development conveniently considered in two stages, time elapsed respectively less or greater than fluctuations. An expression given spectrum initial stage (§ 3.2), it shown prominent ripples wavelength λcr = 1·7 cm, corresponding minimum phase velocity c (4gT/ρ)1/4 moving directions cos-1(c/Uc) mean wind, where Uc ‘convection velocity’ fluctuations length scale approximately wind height above surface. Observations Roll (1951) have existence under appropriate conditions, qualitatively similar those predicted theory.Most growth gravity second, principal development, continues until grow high non-linear effects become important. derived 4.1), follows result square on t time, convection fluctuations, ρ density. This prediction consistent published oceanographic measurements 4.3).It suggested this more effective Jeffreys (1924, 1925) Eckart (1953), may provide whereby energy transferred waves.