Previously, the authors have designed and implemented an active motion control “virtual crankshaft” for a free piston engine, which enables precise piston tracking of desired trajectories. With this mechanism, the volume of the combustion chamber can be regulated, and therefore the pressure,...

The viscosity of the electrolyte in vanadium redox flow batteries (VRFBs) varies during charge and discharge as the concentrations of acid and vanadium ions in the electrolyte continuously change with the state of charge (SOC). In previous VRFB models, however, the electrolyte has been treated...