Experimental study on uniformity of dielectric barrier discharge generated by nanosecond pulse in atmospheric air

Dielectric barrier discharge (DBD) with better uniformity, excited by nanosecond pulses, is achieved within 8 mm air gap by using a self-designed DBD structure in airflow. The self-designed DBD structure is characterized by adding a metal rod (MR) in discharge gap, which will produce a local strong electric field and induce surface and volume discharge. It is observed from sequential single periodic discharge images that the uniformity of discharge starts from the electrode edge at the airflow inlet and moves gradually toward downstream under the action of airflow. When the uniformity of discharge is transmitted to a nearby of MR, a stable uniform and symmetrical annular discharge configuration is formed. Besides, that uniform area can be expanded by adding many MRs or MR array in the discharge gap. There is an optimum distance between every two MRs to produce a continuous and maximum discharge area with better uniformity. The above phenomena are mainly ascribed to the change of electric field distribution caused by MR and the charged particles redistribution induced by airflow.