Magneto-mechanical micro-valve for active flow control

Abstract

This paper presents and discusses the development of a normally-off magneto-mechanical airflow microvalve designed for active aerodynamic flow control application. The architecture of the microvalve is composed of a highly flexible mechanical resonator, a miniature coil enabling the magnetic resonator actuation and a packaging with oval shape. The resonator system consists in an elastomer membrane and miniature magnets. The device fabrication process is based on micro-molding, micromachining and rapid prototyping. The pulsed micro-jet delivered by this microvalve can be used at different duty cycles and frequencies going up to 750 Hz. The micro-jet velocity reached 100 m/s for a corresponding airflow rate of 3 L/min. An array of twenty microvalves was implemented on an Ahmed body model and separation flow control experiments were successfully performed. The actuation provided by the micro-jets decreased by 4.3 % the drag on the vehicle-like shape.