Max Planck Institute for Dynamics and Self-Organization -- Department for Nonlinear Dynamics and Network Dynamics Group
Personal tools
Log in

BFNT/BCCN Sonderseminar

Thursday, 22.03.2012 14 c.t.

Numerical Simulation of a Wind-Driven Air-Water Interface focusing on Thermal Effects

by Fabian Bock
from Universität Heidelberg

Contact person: Theo Geisel

Location

MPI DS seminar room (0.77/0.79)

Abstract

This work focuses on the impact of thermal convection on the motion and heat transport at the air-sea interface for moderate wind speeds. The study of these transport processes is highly relevant for climate research. For this purpose, a numerical model for the simulation of wind-driven water waves has been extended by the effect of thermal convection. Its impact is analyzed for several quantities at and beneath the surface. The results show a very small impact of thermal convection even for a strong heat flux of 3000 W/m^2 at the surface. It is concluded that the thermal convection can be neglected in the study of near-surface processes for moderate wind speeds. Furthermore, the original model has been improved so that the simulation results measure up to reality. This approach is focused on the thermal pattern at the water surface. First, the numerical error is reduced by 35% by the optimization of the dealiasing scheme. Using this improved accuracy, the real Prandtl number Pr = 7 could be applied in the model. The value Pr = 1 was chosen before for accuracy concerns. The increase of Prandtl number leads to signicantly smaller structures at the surface. These new results are more consistent with the experimental observations both qualitatively and quantitatively.

back to overview