On Dissipation inside Turbulent Convection Zones from Three-dimensional Simulations of Solar Convection
The development of two-dimensional and three-dimensional simulations of solar convection has lead to a picture of convection quite unlike the usually assumed Kolmogorov spectrum turbulent flow. We investigate the impact of this changed structure on the dissipation properties of the convection zone, parameterized by an effective viscosity coefficient. We use an expansion treatment developed by Goodman & Oh, applied to a numerical model of solar convection, to calculate effective viscosity as a function of frequency and compare this to currently existing prescriptions based on the assumption of Kolmogorov turbulence. The results quite closely match a linear scaling with period, even though this same formalism applied to a Kolmogorov spectrum of eddies gives a scaling with a power-law index of 5/3.