Secondary Instabilities in Langmuir Circulations

View More View Less
  • 1 School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada
  • 2 Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York
© Get Permissions
Full access

Abstract

Finite-amplitude Langmuir circulation in the form of rolls parallel to the wind direction is shown to be subject to three-dimensional instability under certain circumstances. Density stratification is not required for instability to manifest. The preferred form of this secondary instability appears to be traveling waves propagating in the direction of the wind. These cause the rolls, and their surface windrows, to deviate from the wind direction by a small angle for which estimates are given. The results of the paper show the value of secondary stability results for the design of numerical experiments to simulate Langmuir circulation.

Abstract

Finite-amplitude Langmuir circulation in the form of rolls parallel to the wind direction is shown to be subject to three-dimensional instability under certain circumstances. Density stratification is not required for instability to manifest. The preferred form of this secondary instability appears to be traveling waves propagating in the direction of the wind. These cause the rolls, and their surface windrows, to deviate from the wind direction by a small angle for which estimates are given. The results of the paper show the value of secondary stability results for the design of numerical experiments to simulate Langmuir circulation.

Save