Parametric Study and Optimization of Flow Characteristics of Wire-Nonparallel Plate-Type Electrostatic Air Accelerators

Abstract

Wire and nonparallel plate electrode-type electrostatic air accelerators have attracted significant interest. The physical process involved in using accelerators is complicated. Moreover, mechanisms are unclear, especially for accelerators with double- and multiwire electrodes. In this study, the two-dimensional (2D) model of a wire-nonparallel plate-type accelerator validated by experiments is established with a finite element method. Onset voltage, average current, and outlet average velocity are analyzed with respect to different parameters. Onset voltage is derived by the proposed quadratic regression extrapolation method. Moreover, current is affected by interference and discharge effects, while velocity is also influenced by the suction effect. For the single-wire electrode, high wind speed can be obtained by either increasing channel slope or placing the wire near the entry section. For the double-wire electrode, velocity can be further increased when one of the wires is placed near the inlet and the distance between the two wires is widened. Comparatively, the velocity of the three-wire electrode is higher with larger gaps between wires and stronger discharge effect. The highest velocity is obtained by the four-wire electrode. Comparisons indicate that higher velocity can be obtained with weaker interference effect, stronger suction effect, and intensified discharge effect. Optimum parameter combinations are considered by the Taguchi method. Consequently, velocity can be enhanced by more than 39% after optimization compared with the reference design.