Various embodiments of an airfoil and machines with airfoils are disclosed. The airfoils include a thicker leading airfoil portion and a thinner trailing airfoil portion. In one embodiment, the leading airfoil portion is formed by bending a body of the airfoil back toward itself. In another embodiment, the leading airfoil portion has a solid geometry and includes two elliptic surfaces. To prevent detachment of airflow, the leading airfoil portion includes at least two arc portions or surfaces that act to direct the airflow down to the trailing airfoil portion in a manner that stabilizes vortexes that may form in the region of changing thickness.

Various embodiments of an airfoil and machines with airfoils are disclosed. The airfoils include a thicker leading airfoil portion and a thinner trailing airfoil portion. In one embodiment, the leading airfoil portion is formed by bending a body of the airfoil back toward itself. In another embodiment, the leading airfoil portion has a solid geometry and includes two elliptic surfaces. To prevent detachment of airflow, the leading airfoil portion includes at least two arc portions or surfaces that act to direct the airflow down to the trailing airfoil portion in a manner that stabilizes vortexes that may form in the region of changing thickness.

An arrangement to control vibrations in a gas turbine exhaust diffuser is provided. The arrangement includes a protrusion coupled to a turbine exhaust cylinder strut for controlling shock induced oscillations in a gas turbine diffuser. The controlled shock induced oscillations minimize pressure fluctuations in the gas turbine exhaust diffuser such that an unsteadiness of the fluid flow surrounding the turbine exhaust cylinder strut is reduced. A method to fluid flow induced vibrations in a gas turbine diffuser is also provided.

There is provided a manufacturing method of a fluid flow straightening member having a structure in which disturbance of an air flow does not easily arise. In at least one of outermost layers of an outer circumferential surface or an inner circumferential surface which configures a tubular portion of the fluid flow straightening member, ceramic fibers are oriented in a direction along a plane including a central axis which is surrounded by the tubular portion.

There is provided a manufacturing method of a fluid flow straightening member having a structure in which disturbance of an air flow does not easily arise. In at least one of outermost layers of an outer circumferential surface or an inner circumferential surface which configures a tubular portion of the fluid flow straightening member, ceramic fibers are oriented in a direction along a plane including a central axis which is surrounded by the tubular portion.

In an embodiment, the present disclosure pertains to a cavitation generation device that includes a dactyl plunger rotatable about an axis between an open position and a closed position and a propus socket having a channel. The propus socket is rigidly mounted below the dactyl plunger, and the dactyl plunger is received into the propus socket when the dactyl plunger is in the closed position. The cavitation generation device can also include a torsion spring that biases the dactyl plunger into contact with the propus socket. In another embodiment, the present disclosure pertains to a method of inducing a cavitation including biasing a dactyl plunger via a torsion spring, and rotating the dactyl plunger, by action of the torsion spring, into a propus socket. The propus socket includes a nozzle-shaped channel. The method further includes ejecting a socket cavity volume through the nozzle-shaped channel thereby inducing a cavitation event.

A fluidic oscillator having independent frequency and amplitude control includes a fluidic-oscillator main flow channel having a main flow inlet, a main flow outlet, and first and second control ports disposed at opposing sides thereof. A fluidic-oscillator controller has an inlet and outlet. A volume defined by the main flow channel is greater than the volume defined by the controller. A flow diverter coupled to the outlet of the controller defines a first fluid flow path from the controller's outlet to the first control port and defines a second fluid flow path from the controller's outlet to the second control port.

A vortex flow apparatus including a cylindrical housing that contains a fluid that flows in a swirling circular path. The apparatus may be utilized as a muffler for a combustion engine, a particle separator, or an energy conversion device that physically or chemically acts upon the fluid flow and particles contained within the apparatus. The housing defines an inlet opening that opens into the first end of the housing proximate a first end wall. An outlet tube defines an outlet opening through a first end wall. A projection is attached to a second end wall of the housing and extends into the housing. The outlet tube and projection are aligned with and centered relative to a central axis.

A synthetic jet actuator and a method for optimizing a synthetic jet actuator to meet operating requirements and physical constraints may include estimating dimension and a resonance frequency of an air cavity of the synthetic jet actuator, and using the estimated resonance frequency to the estimate dimensions of a piezoelectric actuator of the synthetic jet actuator. Individual simulations of the air cavity and piezoelectric actuator, and a coupled simulation may be performed using the estimated dimensions, and the dimensions may be revised and simulations re-executed to match the resonance frequencies of the air chamber and the piezoelectric actuator. The method maybe yield a synthetic jet actuator having a resonance frequency of the piezoelectric actuator that is approximately equal to a quarter-wavelength resonance frequency of the air cavity.

Described is a baffle comprising a continuous outer edge and an interior portion enclosed by the outer edge and connected to the outer edge. The interior portion comprises one or more teeth each having a tip directed towards the centre of the baffle, a base adjacent to the outer edge, and a tooth edge joining the tip to the base, wherein at least a portion of the tooth edge defines at least a portion of an aperture extending from a first face to a second face of the baffle.