In the present research, the performance of the electrohydrodynamic force in an asymmetric surface dielectric barrier discharge actuator has been investigated at diferent bias voltages. The efects of DC, AC plus DC (DC-ofset), and sinusoidal bias voltages on the force generation have been studied through measuring the electric wind velocity profles, surface potential, and electric feld. The results showed that applying DC and DC-ofset biases to the lower electrode instead of connecting it to the ground in a typical case increased the charge deposition on the dielectric surface and consequently reduced the electrohydrodynamic force generation. This efect was also observed in case of exchanging these voltages with AC sinusoidal voltage of the upper electrode. In addition, as a new idea, two-phase shifted AC voltage was applied to the electrodes and the resulting changes have been studied. The obtained results at 180◦ phase diference were very noticeable and showed 46% improvement in the maximum velocity of the induced fow relative to the grounded electrode with the same input power. Using this technique, a certain wind velocity can be obtained at relatively lower voltages and input powers compared to the conventional case of grounding the lower electrode. Such a capability is signifcant in aerodynamic applications, where applying large values of the high voltages may disturb the operational systems.
