Comparison of entropy production rates in two different types of self-organized flows: Bnard convection and zonal flow

Two different types of self-organizing and sustaining ordered motion in fluids or plasmas-one is a Bnard convection (or streamer) and the other is a zonal flow-have been compared by introducing a thermodynamic phenomenological model and evaluating the corresponding entropy production rates (EP). These two systems have different topologies in their equivalent circuits: the Bnard convection is modeled by parallel connection of linear and nonlinear conductances, while the zonal flow is modeled by series connection. The power supply that drives the systems is also a determinant of operating modes. When the energy flux is a control parameter (as in usual plasma experiments), the driver is modeled by a constant-current power supply, and when the temperature difference between two separate boundaries is controlled (as in usual computational studies), the driver is modeled by a constant-voltage power supply. The parallel (series)-connection system tends to minimize (maximize) the total EP when a constant-current power supply drives the system. This minimum/maximum relation flips when a constant-voltage power supply is connected.