On the azimuthal structure of thermal convection in circumstellar disks

We study the three-dimensional (3D) global structure of thermal convection in a protoplanetary accretion disk. For that purpose, we have developed a new, versatile 3D hydrocode that incorporates radiation transport and tensor viscosity in different coordinate systems. The code was extensively tested internally by recalculating the most recent models of circumstellar disk convection. With our new code we were able, for the first time, to simulate the large-scale (azimuthal) structure of circumstellar disk convection as it will develop under the assumption of an a viscosity. We find that axisymmetry is broken and convective motions with an azimuthal wavelength of about 4 pressure scale heights form.