Electroaerodynamic (EAD) propulsion, where thrust is produced by collisions between electrostatically-accelerated ions and neutral air, is a potentially transformative method for indoor flight owing to its silent and solid-state nature. Like rotors, EAD thrusters exhibit changes in performance based on proximity to surfaces. Unlike rotors, they have no fragile and quickly spinning parts that have to avoid those surfaces; taking advantage of the efficiency benefits from proximity effects may be a route towards longer-duration indoor operation of ion-propelled fliers. This work presents the first empirical study of ground proximity effects for EAD propulsors, both individually and as quad-thruster arrays. It focuses on multi-stage ducted centimeter-scale actuators suitable for use on small robots envisioned for deployment in human-proximal and indoor environments. Three specific effects (ground, suckdown, and fountain lift), each occurring with a different magnitude at a different spacing from the ground plane, are investigated and shown to have strong dependencies on geometric parameters including thruster-to-thruster spacing, thruster protrusion from the fuselage, and inclusion of flanges or strakes. Peak thrust enhancement ranging from 300 to 600% is found for certain configurations operated in close proximity (0.2 mm) to the ground plane and as much as a 20% increase is measured even when operated centimeters away.

翻译：电空气动力（EAD）推进通过静电加速离子与中性空气碰撞产生推力，因其静音和固态特性，成为室内飞行的一种潜在变革性方法。与旋翼类似，EAD推进器的性能会随接近表面的距离而变化；但不同于旋翼的是，它们没有脆弱且高速旋转的部件需要避开这些表面；利用接近效应带来的效率提升，可能是实现离子推进飞行器更长时间室内运行的一条途径。本文首次对EAD推进器（包括单个和四推进器阵列）的地面接近效应进行实证研究，重点关注适用于小型机器人的多级管道式厘米级致动器，这些机器人预计部署在人类附近及室内环境中。研究了三种特定效应（地面效应、吸下效应和喷泉升力），它们在地面不同间距处表现出不同强度，并显示出对几何参数（包括推进器间距、推进器突出机身程度、以及是否包含法兰或边条）的强依赖性。在紧贴地面（0.2毫米）运行的某些配置中，峰值推力增强可达300%至600%，即使在距离地面数厘米处运行时，也测得了高达20%的推力增加。