Toroidal counter electrode for ionic propulsion

Abstract

Significant attention has recently been given to applications of ionic wind to atmospheric propulsion. Rotational ionic engines (RIE) have also demonstrated to have potential for in-atmosphere propulsion in negative polarity. However, such devices have not yet produced enough thrust for a rotary ionic drone to be developed. We demonstrate here that a toroidal counter electrode can increase the RIE's performance by up to 7.8 times greater than in previous configurations (upper limit not determined). The RIE is designed with pin emitters extended on the trailing edge of a 12.6 cm two-blade plastic propeller placed above a toroidal counter-electrode which provided axial thrust up to 288.55 m Nat 23.15 N/m2, 4.2 m/s bulk airflow speed within the propeller plane, and 251 m3/h flow rate. The new design generates axial thrust due to the linear acceleration of ions between electrodes, and also due to the induced rotary motion of the propeller which captures the energy and momentum of ions accelerated in the propeller rotational plane. Thrust to power ratio can be measured by the ratio of voltage to current or propeller kinetic energy to power. A 4-RIE array matched the thrust (1 N) of a four-blade drone with similar blade size.