This paper presents an experimental investigation on flow field induced by a dielectric barrier discharge(DBD) plasma actuator with serrated electrodes in still air to further improve its flow control effectiveness. F...This paper presents an experimental investigation on flow field induced by a dielectric barrier discharge(DBD) plasma actuator with serrated electrodes in still air to further improve its flow control effectiveness. For comparison, the actuator with widely used linear electrodes was also studied. Experiments were carried out using 2D particle image velocimetry. Particular attention was given to the flow topology, discharge phenomenon, and vortex formation mechanism. Results showed that a 2D wall jet was induced by the linear actuators, whereas the plasma actuators with serrated electrode introduced a series of streamwise vorticities, which might benefit flow control(e.g., enhancing the momentum transport in the separated boundary flow). In addition, the mechanism of 3D flow topology induced by the serrated DBD actuator was analyzed in detail.展开更多
The medium access control(MAC) protocol for indoor visible light communication(VLC) with energy harvesting is explored in this paper. The unfairness of throughput exists among devices due to the significant difference...The medium access control(MAC) protocol for indoor visible light communication(VLC) with energy harvesting is explored in this paper. The unfairness of throughput exists among devices due to the significant difference of their energy harvesting rates which changes with distance, acceptance angle and the obstruction probability. We propose an energy harvesting model, a new obstruction probability model and an energy adaptive contention algorithm to overcome the unfairness problem. This device can adjust its contention window according to the energy harvesting rate. As a result, the device with lower energy harvesting rate can get shorter contention window to improve its transmission opportunity. Simulation results show that our MAC protocol can achieve a higher degree of fairness.展开更多
基金supported by the National Natural Science Foundation of China (51222606)
文摘This paper presents an experimental investigation on flow field induced by a dielectric barrier discharge(DBD) plasma actuator with serrated electrodes in still air to further improve its flow control effectiveness. For comparison, the actuator with widely used linear electrodes was also studied. Experiments were carried out using 2D particle image velocimetry. Particular attention was given to the flow topology, discharge phenomenon, and vortex formation mechanism. Results showed that a 2D wall jet was induced by the linear actuators, whereas the plasma actuators with serrated electrode introduced a series of streamwise vorticities, which might benefit flow control(e.g., enhancing the momentum transport in the separated boundary flow). In addition, the mechanism of 3D flow topology induced by the serrated DBD actuator was analyzed in detail.
文摘The medium access control(MAC) protocol for indoor visible light communication(VLC) with energy harvesting is explored in this paper. The unfairness of throughput exists among devices due to the significant difference of their energy harvesting rates which changes with distance, acceptance angle and the obstruction probability. We propose an energy harvesting model, a new obstruction probability model and an energy adaptive contention algorithm to overcome the unfairness problem. This device can adjust its contention window according to the energy harvesting rate. As a result, the device with lower energy harvesting rate can get shorter contention window to improve its transmission opportunity. Simulation results show that our MAC protocol can achieve a higher degree of fairness.
