Internal Heating, why Convective Driving Models Matter for Astrophysics

Convection drives mixing in stars, brown dwarfs, and gas giant planets. Convection in stars is driven by internal heating caused by changes in radiative conductivity or nuclear burning. In planets, convection is driven by changes in radiative conductivity and heat from gravitational contraction. However, most multi-dimensional models of stellar and planetary convection use hard boundaries, driving convection with fixed temperatures or fluxes at the top and bottom of the domain which can drive non-physical flows. With an internally heated convection model heat is deposited throughout the domain, which mimics the natural processes in stars and planets. In this work we study the fundamental properties of internally heated convection. This model gives us independent control over flow speed and turbulence in our simulations and provides consistent behavior in power spectra. This will enable us to conduct better experiments to study convection in astrophysical systems.