Frequency Response of Gas-Filled Tube With Minor Losses

The results of a study of the frequency response of a pneumatic system designed to provide pulsed flow for flow control applications are presented. The system consists of a high pressure air source, a high-frequency solenoid valve, a length of tube and a minor loss. The experiment mimics the pneumatic drive for our Coanda-Assisted Spray Manipulation actuator and applies to many flow control applications involving pulsed flow. Square wave signals of various frequency were fed to the solenoid valve. The flow at the exit of the flow system was measured with a single hot wire and compared to steady flow through the same geometry. The effect of the inlet pressure, tube length and the size and position of the minor loss were tested. These data are modeled using a Transmission Matrix Model in.