Solution of Rayleigh's instability equation for arbitrary wind profiles


Beji S., NADAOKA K.

JOURNAL OF FLUID MECHANICS, cilt.500, ss.65-73, 2004 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 500
  • Basım Tarihi: 2004
  • Doi Numarası: 10.1017/s0022112003007262
  • Dergi Adı: JOURNAL OF FLUID MECHANICS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.65-73
  • İstanbul Teknik Üniversitesi Adresli: Hayır

Özet

A different approach to the solution of the singular Rayleigh equation is presented in the context of the water wave growth problem as modelled by wind-induced shear instabilities. The approach is based on the analytical solution of a Bessel equation in the vicinity of the singular point, which is obtained from Rayleigh's equation with an arbitrary wind profile. Wave growth rates are computed using an integral expression derived from the dispersion relation of the air-sea interface. Computations of the present approach agree well with those of Conte & Miles (1959) for the special case of a logarithmic wind profile. Effects of the shape of the wind profile on the wave growth rate are investigated by using the 1/7-power law to represent the wind profile. Comparisons of the growth rates for the logarithmic wind profile and for the 1/7 profile reveal appreciable differences which must be investigated further, possibly using measured wind profiles within 10m above the sea surface.