Instabilities in Protoplanetary Disks and Their Effects on Planetesimal Formation in the Low Turbulence Limit

Abstract

This thesis uses hydrodynamic simulations to explore the properties of protoplanetary disks in the limit of weak turbulence and small particles. It characterizes the nature of the Kelvin-Helmholtz instability that is expected after the initial settling phase in disks containing small grains. These disks generate levels of turbulence consistent with observations. Values of the Shakura-Sunyaev turbulence parameter α are extracted directly from the simulations and are found to be approximately α = 2.7 × 10−5. The implications of high and low values of α on planet formation are investigated, showing that planets can still form in disks with weak turbulence. We explore the associated constraints on planet formation and how they may affect the formation of planets at different radii within plausible planet forming disks.