A device includes a fluid flow channel having a channel inlet for receiving a pressurized fluid for flow through the fluid flow channel and a channel outlet for discharging the pressurized fluid therefrom. A passive flow element is situated within the fluid flow channel or proximate to the channel inlet. The passive flow element includes an element inlet for receiving the pressurized fluid, and an element outlet. The passive flow element also includes a cavity for receiving the pressurized fluid from the element inlet and generating a periodic flow variation of the pressurized fluid so as to modulate the pressurized fluid flow rate through the element outlet.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH & DEVELOPMENT
 This invention was made with Government support under contract number DE-FC26-05NT42643 awarded by U.S. Department of Energy. The Government has certain rights in the invention.