Experimental Investigation of the Flow of a Modified Sweeping Jet Actuator

  • Mariam Amer

Student thesis: Master's Thesis

Abstract

In this work, the effects of geometric changes to a sweeping jet actuator (SWJ) on the oscillating jet properties are studied. The modifications considered are made to the feedback channel dimensions, as well as the mixing chamber size and shape. Several studies over the last few years were carried out to understand the way the characteristics of a sweeping jet can vary with different variation of the internal geometry of the actuator. None, however, focus on the way the actuator material and manufacturing process can affect the resulting jet properties and the effect that varying these parameters can have on the external jet flow. Gaining this understanding can be crucial to finding and controlling the specific actuator design for any given application as well as get some insight into the possibility for mass-producing SWJ actuators using 3D printing. Hence, the purpose of this study is to also find the sweeping jet profiles resulting from the different actuators which are made of acrylic, nylon and metal made using either a milling process or 3D printing. To achieve the objectives, the parameters of interest measured experimentally are the energy required by each actuator, the oscillation frequency, jet spreading angle, and the quality of the pressure signal studied. The results show that the straight line coanda surface and the baseline actuators have similar jet properties. Moreover, the oscillation frequency always increases with the decrease in mixing chamber length, as expected, but the least energy-efficient geometries are those in which the mixing chamber lengths are increased by 10% and 20% of their original length. The longer exit diffuser length increases the sweeping jet spreading angle, and it lowers the energy needed, but it reduces the oscillation frequency. Low actuator roughness values was found to give high jet spreading angle, while more data is needed to investigate how roughness influences the oscillation frequency and required energy supply.
Date of AwardJul 2021
Original languageAmerican English

Keywords

  • Active Flow Control; Sweeping Jet Actuator; Internal Flows; Additive Manufacturing.

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