Zobrazeno 1 - 10
of 203
pro vyhledávání: '"Ellingsen, Simen Å."'
Turbulence beneath a free surface leaves characteristic long-lived signatures on the surface, such as upwelling 'boils', near-circular 'dimples' and elongated 'scars', easily identifiable by eye, e.g., in riverine flows. In this paper, we use Direct
Externí odkaz:
http://arxiv.org/abs/2409.05409
The dispersive motion of surface waves is now routinely used to remotely measure the currents close beneath the surface of oceans and other natural flows. The current manifests as wavelength-dependent Doppler shifts in the spatiotemporal wave spectru
Externí odkaz:
http://arxiv.org/abs/2408.08197
Publikováno v:
IEEE Transactions on Geoscience and Remote Sensing, vol 61, no 4208515 (2023)
Remotely measuring subsurface water currents from imagery of the wave field has become a much-used technique. We study the biases and errors in such measurements due to spectral leakage, and suggest mitigating procedures. Deviations between peak valu
Externí odkaz:
http://arxiv.org/abs/2311.01265
Publikováno v:
Physical Review Fluids vol 8, 014801 (2023)
We investigate how the presence of a vertically sheared current affects wave statistics, including the probability of rogue waves, and apply it to a real-world case using measured spectral and shear current data from the Mouth of the Columbia River.
Externí odkaz:
http://arxiv.org/abs/2301.06381
In this chapter we review methods by which near--surface ocean currents can be measured remotely using images of the water surface, as obtained by X-band radar in particular. The presence of a current changes the dispersive behavior of surface waves,
Externí odkaz:
http://arxiv.org/abs/2205.05373
Publikováno v:
Journal of Fluid Mechanics, vol 926, A9 (2021)
We present direct numerical simulation of a mechanism for creating longitudinal vortices in pipe flow, compared with a simple model theory. By furnishing the pipe wall with a pattern of crossing waves secondary flow in the form of spanwise vortex pai
Externí odkaz:
http://arxiv.org/abs/2104.07731
Publikováno v:
Journal of Fluid Mechanics vol 900, article A19 (2020)
We investigate a mechanism to manipulate wall-bounded flows whereby wave-like undulations of the wall topography drives the creation of bespoke longitudinal vortices. A resonant interaction between the ambient vorticity of the undisturbed shear flow
Externí odkaz:
http://arxiv.org/abs/2005.00317
When shallow water flows over uneven bathymetry, the water surface is modulated. This type of problem has been revisited numerous times since it was first studied by Lord Kelvin in 1886. Our study analytically examines currents whose unperturbed velo
Externí odkaz:
http://arxiv.org/abs/1909.05678
Autor:
Maxwell, Peter, Ellingsen, Simen Å
The path-following scheme in [Loisel and Maxwell, SIAM J. Matrix Anal. Appl., 39-4 (2018), pp. 1726-1749] is adapted to efficiently calculate the dispersion relation curve for linear surface waves on an arbitrary vertical shear current. This is equiv
Externí odkaz:
http://arxiv.org/abs/1905.03187
A new inversion method for determining near-surface shear currents from a measured wave spectrum is introduced. The method is straightforward to implement and starts from the existing state-of-the-art technique of assigning effective depths to measur
Externí odkaz:
http://arxiv.org/abs/1904.11575