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arXiv 2207.09424physics.plasm-ph
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低速外流中介质阻挡放电激励器的动量注入

Momentum Injection via Dielectric Barrier Discharge Actuators in Low-Speed External Flow

Anthony Tang, Benjamin Price, Alexander Mamishev, Alberto Aliseda, Igor Novosselov

摘要:

介质阻挡放电(DBD)等离子体激励器可以在无运动部件的情况下,通过电离分子和中性分子在电场中的相互作用产生壁面射流。在流动边界层中,电流体动力学、湍流和粘性效应之间的耦合仍然不清楚,值得仔细研究。本文对介质阻挡放电(DBD)驱动器在U_external = 5 m/s和U_external = 11 m/s的同向流和反向流结构中的动量注入进行了实验研究,电压范围为12 kV - 19.5 kV,频率为2 kHz。在同向流配置中,DBD致动器向边界层增加动量,类似于静止条件下的电流体动力学(EHD)射流。在逆流配置中,在自由流速度U_external = 5 m/s时观察到流动分离。逆流配置中的动量位移比静止环境中的EHD射流动量大约6倍。随着外部流速的增加,同向流和反向流动量注入的影响逐渐减小。这项工作突出表明,所产生的流型不是EHD射流和自由流的简单叠加,而是由EHD和外部流的惯性力、粘性力和库仑力之间的平衡决定的。速度分布和动量特性可以用来验证数值模型,并通知主动流动控制的DBD致动器的设计。

英文摘要:

Dielectric barrier discharge (DBD) plasma actuators can generate a wall jet without moving parts through interaction between ionized and neutral molecules in an electric field. The coupling between electro-hydrodynamic, turbulence, and viscous effects in the flow boundary layer remains unclear and deserves careful investigation. We present an experimental investigation of momentum injection by DBD actuators in a U_external = 5 m/s and U_external = 11 m/s co-flow and counter-flow configuration over a range of VAC = 12 kV - 19.5 kV peak-to-peak at a frequency of 2 kHz. In the co-flow configuration, the DBD actuator adds momentum to the boundary layer, similar to an electrohydrodynamic (EHD) jet in quiescent conditions. In the counter-flow configuration, flow separation is observed at free stream velocity U_external = 5 m/s. The momentum displacement in the counter-flow configuration is ~ 6x greater than EHD jet momentum in a quiescent environment. Both co-flow and counter-flow momentum injections show diminishing effects with increased external flow speed. This work highlights that the resulting flow pattern is not a simple superposition of the EHD jet and the free stream but is determined by a balance between the inertial, viscous and Coulombic forces of the EHD and the external flow. The velocity profiles and momentum characteristics can be used to validate numerical models and inform the design of DBD actuators for active flow control.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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