The book reports on the latest theoretical and experimental findings in the field of active flow and combustion control, in the context of energy conversion for power and propulsion systems. It covers new developments in actuator technology and sensing, robust and optimal open- and closed-loop control, model reduction for control purposes, and unsteady turbine cooling and performance, among other relevant topics. Gathering contributions to the Active Flow and Combustion Control (AFCC 2021), held virtually on September 28-29, 2021, from the Technische Universit