초록 ▼

The present invention involves micromachined synthetic jet actuators, or "microjet" actuators. These fluidic control devices may be fabricated using standard silicon micromachining techniques and comprise an orifice situated atop an actuator cavity which is bounded at least partially by a flexible m

The present invention involves micromachined synthetic jet actuators, or "microjet" actuators. These fluidic control devices may be fabricated using standard silicon micromachining techniques and comprise an orifice situated atop an actuator cavity which is bounded at least partially by a flexible membrane. Alternatively, microjets may be formed in more robust substrates, such as metals or ceramics. Vibration of the membrane using either electrostatic or piezoelectric drives results in a turbulent air jet formed normal to the microjet orifice. The jet stream is synthesized by a train of vortex rings. Each vortex is formed by the motion of the diaphragm and is advanced away from the jet under self-induced velocity. Alternatively, the microjet actuator can comprise a "piston in cylinder" to take the functional place of the vibrating diaphragm. This can be accomplished by changing the aspect ratio of the actuator cavity to a deeper, more cylindrical shape. A piston-like actuator can then be realized by using a "bossed" diaphragm. An improvement to microjets is the use of modulators with the jet actuators. Modulators are generally devices to selectively cover and uncover the orifice of a synthetic jet actuator in order to prevent either flow into or out of the jet cavity. Such modulators are fabricated as either vertical drive, lateral drive or constricting modulators.

대표청구항 ▼

1. A micromachined synthetic jet apparatus placed in an environment having an ambient fluid, comprising:(a) a substrate material defining a cavity having a volume of the ambient fluid and one orifice on a face of said substrate for allowing fluid communication between said cavity and the environment

1. A micromachined synthetic jet apparatus placed in an environment having an ambient fluid, comprising:(a) a substrate material defining a cavity having a volume of the ambient fluid and one orifice on a face of said substrate for allowing fluid communication between said cavity and the environment; and (b) a volume changing means for changing a volume within said cavity so that when said cavity volume is increased, a portion of the ambient fluid is drawn into said cavity, and when said cavity volume is decreased a portion of the ambient fluid is emitted from said orifice and forms a series of fluid vortices projected in the environment out from the orifice, wherein said vortices entrain a portion of the ambient fluid thereby generating a synthetic jet stream.