Abstract Current study is focused on numerically finding an optimal active control system to augment the natural heat transfer through a vertical duct. This control system consists of a multiple set of wall embedded Dielectric-Barrier-Discharge (DBD) plasma actuators, which inherently consume the electric power to push the momentum near their embedded electrodes. On the other hand, in current study which the vertical duct is exposed to a constant heat flux on one side, the enhancement of natural convection by wall momentum pushes cause the upward flow to recirculate through the channel and consequently decelerates the mass flow rate to give higher outflow temperatures. The numerical simulation deals with the effects of variable parameters such as Rayleigh number, number of DBD actuators, and the vertical DBD arrangements. A descriptive enhancement ratio: The ratio of the average Nusselt number affected by plasma actuation to the average Nusselt number without DBD control, is used to evaluate capability of the heat transfer augmentation. The numerical results showed that the enhancement ratio in the presence of the DBD actuator reaches to about 2.75. However, the results briefly show the sensitivity of the heat transfer enhancement to the Number of the actuators and their arrangement. As the main goal and the final step, the overall thermal efficiency (OTE) as a parameter expressed to further clarify the performance of plasma actuator system from the perspective of energy consumption is defined as the rate of the augmented heat transfer by the DBD actuator to the actuation electric power consumption. Also, it can be realized that by increasing the number of DBD actuators from 1 to 4, the La increases, and over 4 it is constant. The results show that the case N = 4 can be a candidate for the optimum design.

中文翻译：

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寻找一种低成本能量多 DBD 等离子体执行器，以增强垂直管道中的自然传热

摘要 当前的研究集中在数值上寻找最佳主动控制系统，以增加通过垂直管道的自然热传递。该控制系统由多组壁嵌式介电势垒放电 (DBD) 等离子体致动器组成，这些致动器本质上消耗电能以推动其嵌入式电极附近的动量。另一方面，在目前的研究中，垂直管道在一侧暴露于恒定的热通量中，壁面动量推动自然对流的增强导致向上流动通过通道再循环，从而降低质量流速以给出更高的流出温度。数值模拟处理诸如瑞利数、DBD 致动器数量和垂直 DBD 布置等可变参数的影响。描述性增强比：受等离子体驱动影响的平均努塞尔数与没有 DBD 控制的平均努塞尔数之比，用于评估传热增强的能力。数值结果表明，在存在 DBD 执行器的情况下，增强比达到约 2.75。然而，结果简要显示了传热增强对执行器数量及其布置的敏感性。作为主要目标和最后一步，整体热效率（OTE）作为一个参数表达，从能耗的角度进一步阐明等离子体致动器系统的性能，定义为 DBD 致动器对热传递的增强速率。驱动电力消耗。还，可以看出，通过将 DBD 执行器的数量从 1 增加到 4，La 增加，超过 4 则为常数。结果表明，N = 4 的情况可以作为优化设计的候选。