Model of Multistaged Ducted Thrusters for High-Thrust-Density Electroaerodynamic Propulsion

Abstract

Electroaerodynamic (EAD) thrusters are a means of producing a propulsive force in air that does not require any moving parts and is nearly silent. In these devices, ions generated from atmospheric air are accelerated by an electric field across two electrodes at different potentials, resulting in an ionic wind and a thrust force. It has been demonstrated that EAD is a feasible form of aircraft propulsion; however, substantial performance improvements are needed for practical applications. Here, multistaged ducted (MSD) EAD thrusters, which have the potential to provide higher thrust density than previously demonstrated, are proposed and modeled. An MSD thruster contains multiple sets of electrode pairs in series, enclosed in a duct and fitted with an inlet and a nozzle. One-dimensional momentum theory is combined with models for two limiting cases for the pressure generated by each stage: ideal one-dimensional EAD stages and wire-to-airfoil corona-discharge stages. The model evaluates how geometric and electrical parameters affect the performance of MSD thrusters under both sets of assumptions. If pressure losses per stage are kept small, the results show that MSD thrusters can provide order-of-magnitude improvements in thrust density and efficiency as compared to single-stage thrusters, potentially broadening the type of missions that can be performed by EAD thrusters.

Blade emitters for atmospheric ionic thrusters

“…Moreover, decreasing the gap would decrease the thrust-to-power ratio and increase the mass of the final thruster, which depends on the power demand. In this regard, in the literature the range of interest of S/d for some wire-cylinder geometries lies approximately between 0.1-3.5 [19,22], while for wire-airfoil geometries is between 0.4 and 5 [13,17,20]. Optimal values which maximize thrust density can be found, however they may depend on the configuration under study: for airfoil collectors in particular, besides S/d, their chord-to-gap and thickness-to-gap ratios c/d, t/d also affect the performance, so that for different airfoils of the NACA family the optimal S/d ratios appear in a range between 0.5 and 1.5 [20,23].…”

“…When dealing with studies on the electrodes' geometry, it is important to introduce proper scaling relations in order to identify the physically meaningful parameters and avoid introducing repeated tests which involve similar physics on different scales. This problem has been addressed in different works [12,13,19,20], and it has been shown by [13] that the shielding effect for a given emitter shape is highly dependent on the spacing-to-gap ratio S/d. By increasing the spacing S between emitters or reducing the emitters-collectors gap d their ratio increases and the detrimental electrostatic interaction can be reduced, thereby promoting a better emitter-collector interaction.…”

Modeling of the Flight Performance of a Plasma-Propelled Drone: Limitations and Prospects

“…Tremendous work is being carried out by various teams around the world to improve the performance of multistage thrusters. Efforts are especially made to increase the efficiency by ducting thrusters [31][32][33] and modifying the shape and number of electrodes [32,34] to reduce losses. As more work is carried out, it can be expected that the laws and estimations presented in the previous section will change.…”

“…where Pd a is determined via Equation (32). These equations are displayed in Figure 9 for both single-and dual-collector cases.…”

“…where the power Pa is computed through Equation (32) or Equation (33), depending on the selected configuration. The definition of two constants allows for either the simulation of a more effective thruster than the reference [5] by only reducing the power consumption at the reference thrust generation or an increase in the thrust generation at the reference power consumption.…”