Three-Layer Composite Dielectric Structure for Ionic Wind Actuator at Near Space

Based on surface dielectric barrier discharge (SDBD), this article proposes a composite dielectric structure for ionic wind actuator in near space. The performance difference between the actuator of quartz-air-quartz three-layer composite structure and single-layer quartz glass was investigated. The experimental results show that compared with the single-layer quartz glass actuator, the dynamic permittivity of the actuator with three-layer composite dielectric decreases by about 63%, and the maximum flow velocity reaches 0.95 and 0.99 m/s. The maximum thrust of the actuator with three-layer composite dielectric is about $792 \mu \text{N}$ /m, which increases by 25.7%, and the voltage and input power corresponding to the saturation point of thrust increase by 14.0% and 31.8%, respectively. The maximum force-to-weight ratio of the actuator with single-layer quartz glass is $988 \mu \text{N}$ /kg, and the maximum force-to-weight ratio of the actuator with three-layer composite dielectric is $2329 \mu \text{N}$ /kg, which increases by about 135.7%. The different dielectric properties of multilayer composite dielectric lead to different electric field intensities and current densities in different dielectrics. Therefore, the space charge limiting current effect (SCLC) appears at the interface of dielectric, which has a significant regulating effect on the space charge deposited on the dielectric surface in the discharge plasma region and effectively improves the charge distribution in the discharge region. The dynamic performance of the actuator is improved.