Experimental study for momentum transfer in a dielectric barrier discharge plasma actuator

The momentum-transfer performance of a plasma actuator was investigated experimentally for the effects of ambient-gas pressure, ambient-gas species, and electrode configuration. For measurement of the momentum-transfer performance, the force exerted by the actuator, in addition to the induced velocity, was measured; the consistency between both measurement methods was demonstrated. Results showed that the ambient-gas pressure under which a plasma actuator operates has a considerable effect on the momentum-transfer performance. In fact, the performance does not decrease in a linear manner with decreasing ambient-gas pressure; rather, it initially increases and then decreases. The chemical species of the ambient gas also has a considerable effect on the momentum-transfer performance. The momentum transfer in air is greater than that in nitrogen gas at pressures of less than 1 atm, which suggests a considerable contribution of oxygen molecules in the air. The momentum-transfer performance in carbon dioxide gas is slightly greater than that in nitrogen gas for pressures of less than 1 atm, although they are comparable at 1-atm pressure. Furthermore, the electrode configuration was found to strongly affect the momentum-transfer performance of the plasma actuator. In particular, a mesh-type electrode can improve the performance markedly, compared with the performance of a tape electrode with similar thickness, in an ambient-gas pressure of I atm. However, the performance difference attributable to the electrode configuration is greatly reduced with a decrease in the ambient-gas pressure; for example, it almost disappears at pressures of less than approximately 50 kPa.