Effect of three-dimensional structures on the dynamics of turbulence in thin layers of fluid in a laboratory experiment

The results of experiments on turbulent flows excited by the Ampere force in a thin layer of a conducting fluid over a solid surface upon the passage of a current and the action of a spatially periodic magnetic field are considered. Third-order longitudinal structure functions of the velocity field are shown to be approximately linear in the spatial shift and negative even at horizontal scales that exceed the layer thickness by an order of magnitude. This is how the three-dimensional dynamics is manifested as a result of the dominant contribution of energy dissipation when the no-slip boundary condition is satisfied on the lower surface. Dissipation and the main summands of energy production have been estimated for the energy-balance equation.