Shape optimization of a synthetic jet actuator enclosure for aerodynamic efficiency and noise reduction using COMSOL Multiphysics

Synthetic jet actuators are devices that generate a pulsatile flow through cyclic suction and blowing while maintaining a zero net mass flux. Their distinct ability to operate with no external fluid source, short response time, and compactness makes them suitable for use in flow control in aircraft, thrust vectoring of jet engines, and sensor-cleaning in automobiles. However, synthetic jet actuators’ acoustic emissions are an undesirable by-product of their performance. Therefore, this study presents the design and optimization of a streamlined enclosure that enhances the actuator’s aerodynamic efficiency while reducing the radiated noise. A preliminary parametric study is conducted to determine the best initial design of the enclosure based on the enclosure efficiency calculated. Geometric and shape optimization are performed with the objective of minimizing the pressure drop (thus increasing the enclosure’s aerodynamic efficiency). The determined far-field pressure, which quantifies the radiated noise, is also investigated. This study explores several factors, such as computational mesh construction, the suitable optimization algorithm method, and the maximum displacement setting (dmax) in COMSOL Multiphysics, to converge to the optimum enclosure design. The optimum enclosure is 3-D printed and experimentally tested to validate the computational results. [Work supported by McGill University.]