This report summarizes the results of a Department of Energy-funded study on slurry bubble column reactors (SBCR). Alternate fuels projects need high reactor throughput for competitive economics so that reactors must operate in the churn-turbulent region of flow. Little data in this flow regime, especially at the conditions of high pressure and temperature for organic fluids found in an industrial reactor, existed at the inception of this project. This report summarizes the large body of fundamental data that was developed on these flows. It covers both the local liquid turbulence and large-scale liquid internal circulation aspects of flow in the SBCR. Where understood, the underlying mechanisms, which result in the macro-scale phenomena, are elucidated and modeled. Finally, new models for reactor design are also presented.