Extremum Seeking Adaptive Separation Control on a Wing with Plasma Synthetic Jet Actuator

Ogawara, Kakuji; Kojima, Ryosuke; Matsumoto, Shoji; Shingin, Hidenori

doi:10.1299/jfst.7.89

Cited by 5 publications

(2 citation statements)

References 10 publications

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“…Conventionally, influences of the electrically charged air and electric field on the air flow have been studied mainly for the plasma actuators at the smooth surface flows, synthetic jet actuators, e.g. (Ogawara et al, 2012;Miyagi and Kimura, 2014;Shimizu et al, 2019) or electrohydrodynamic (EHD) pumping, e.g. (Yanada et al, 2010;Zhang et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Behaviors of charged air flow on the step surface with an electric potential

MAEDA,

MAEDA

2024

JFST

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As a new perspective on the influences of the electrically charged air and electric field on the air flow, the natural air flow on a negatively charged forward-inclined step is analyzed. The electric field formed by the charged step pushes away the negative charge and attracts the positive charge in natural air, so that only the positive charge density is analyzed. A two-dimensional model of flow and electric field is set and solved on COMSOL Multiphysics FEM solver coupling three physics, that is, flow, electrostatics, and charge-transport. The pressure power spectra at the point around the vortex shedding region are calculated in the case of neutral air / uncharged step and charged air / charged step combinations. Whereas the former has large power below 1Hz, the latter has small power below 1Hz but with a larger peak at 30Hz, that is the vortex shedding frequency. In order to analyze the cause of the difference, the electric force effects are evaluated. The result shows that the upper portion of the vortex has forces in the same direction to the mainstream, and it degrades to the lower portion, which accelerates the vorticity of the vortex. Also, the vortex region has a strong downward force. Adding that, the curl of the electric force on the charged air is calculated to show that the upstream half of the vortex has the same direction curl as the vortex rotation, and the downstream half has an opposite curl because of the gradient charge density. These forces strengthen the vortices and raise their negative pressures and are estimated to suppress the fluctuation of the pressures so that the pressure's spread spectrum reduces. In addition, the results of an experiment using a desktop wind tunnel are given as extra information.

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Section: Introductionmentioning

confidence: 99%

Behaviors of charged air flow on the step surface with an electric potential

MAEDA,

MAEDA

2024

JFST

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“…On the other hand, a large number of studies focused on the working characteristic [24][25][26], efficiency improvement [27,28] and structure optimization [29][30][31] of SPJ actuator. In addition, SPJ actuator has also been used for aerodynamic control [32,33], mixing enhancement [34] and separation control [35][36][37][38].…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Ramp Shock Wave Control in Ma3 Supersonic Flow Using Two-Electrode SparkJet Actuator

et al. 2020

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The control of a shock wave produced by a ramp (ramp shock) in Ma3 supersonic flow using a two-electrode SparkJet (SPJ) actuator in a single-pulse mode is studied experimentally. Except for schlieren images of the interaction process of SPJ with the flow field, a dynamic pressure measurement method is also used in the analysis of shock wave control. In a typical experimental case, under the control of single-pulsed SPJ, the characteristic of ramp shock changes from “short-term local upstream motion” in the initial stage to “long-term whole downstream motion” in the later stage. The angle and position of the ramp shock changes significantly in the whole control process. In addition, the dynamic pressure measurement result shows that the ramp pressure is reduced by a maximum of 79% compared to that in the base flow field, which indicates that the ramp shock is significantly weakened by SPJ. The effects of some parameters on the control effect of SPJ on the ramp shock are investigated and analyzed in detail. The increase in discharge capacitance helps to improve the control effect of SPJ on the ramp shock. However, the control effect of the SPJ actuator with medium exit diameter is better than that with a too small or too large one. In addition, when the SPJ exit is located in the separation zone and outside, the change in the ramp shock shows significant differences, but the control effect in the case of medium ramp distance is better when the SPJ exit is located outside the separation zone.

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