A method of reducing noise from a high-speed, including supersonic, jet, the method includes providing the high-speed or supersonic jet in a longitudinal flow direction; and inducing a rotation of a swirl layer of the high-speed or supersonic jet around a longitudinal direction of the jet and on the jet boundary so as to promote mixing of the high-speed or supersonic jet with surrounding air.

A silencer comprises a main air guide tube provided with an air guide channel; the main air guide tube comprises an air inlet end and an air outlet end; both ends of an assistant air guide tube are connected with an outer wall of the main air guide tube, and the assistant air guide tube comprises a guide section and a reflux section; the guide section is provided with an air inlet, and the air inlet is communicated with the air guide channel; the reflux section is provided with an air outlet, and the air outlet is communicated with the air guide channel.

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 silencer comprises a main air guide tube provided with an air guide channel; the main air guide tube comprises an air inlet end and an air outlet end; both ends of an assistant air guide tube are connected with an outer wall of the main air guide tube, and the assistant air guide tube comprises a guide section and a reflux section; the guide section is provided with an air inlet, and the air inlet is communicated with the air guide channel; the reflux section is provided with an air outlet, and the air outlet is communicated with the air guide channel.

A noise abatement system including at least one fluid circulation chamber to receive at least one flow of fluid; at least one vorticity-inducing component adjacent to the at least one fluid circulation chamber, the at least one vorticity-inducing component to redirect the at least one flow of fluid tangentially to an inside perimeter wall of the at least one fluid circulation chamber to create fluctuations in a flow and pressure of the fluid causing increased and variable vorticity within the at least one fluid circulation chamber; and at least one vorticity-interaction region in communication with the at least one vorticity-inducing component to attenuate acoustics caused by the at least one flow of fluid.

In the present disclosure is proposed a novel sound attenuating element for, at least in part, providing adequate or preferably improved sound attenuating properties without excessively impeding flow while being susceptible to automated or machine assisted manufacturing or for providing the public with a useful alternative. The novel sound attenuating element is formed at least in part by an assembly of a plurality of components which are successively connected to each other, which each exhibit a curved shape, and which form at least one non-planar ruled surface when assembled.

A bilayler metamaterial silencer allows substantial fluid through the apparatus, while mitigating the propagation of sound through the apparatus, and while providing a form factor that is significantly more compact than previously-known devices. Moreover, illustrative embodiments allow a designer to specify one or both of the frequency or frequencies at which the apparatus mitigates sound propagation, and/or the bandwidth around the frequency or frequencies at which the apparatus mitigates sound propagation.

A bilayler metamaterial silencer allows substantial fluid through the apparatus, while mitigating the propagation of sound through the apparatus, and while providing a form factor that is significantly more compact than previously-known devices. Moreover, illustrative embodiments allow a designer to specify one or both of the frequency or frequencies at which the apparatus mitigates sound propagation, and/or the bandwidth around the frequency or frequencies at which the apparatus mitigates sound propagation.

A bilayer metamaterial silencer allows substantial fluid through the apparatus, while mitigating the propagation of sound through the apparatus, and while providing a form factor that is significantly more compact than previously-known devices. Moreover, illustrative embodiments allow a designer to specify one or both of the frequency or frequencies at which the apparatus mitigates sound propagation, and/or the bandwidth around the frequency or frequencies at which the apparatus mitigates sound propagation.

A bilayler metamaterial silencer allows substantial fluid through the apparatus, while mitigating the propagation of sound through the apparatus, and while providing a form factor that is significantly more compact than previously-known devices. Moreover, illustrative embodiments allow a designer to specify one or both of the frequency or frequencies at which the apparatus mitigates sound propagation, and/or the bandwidth around the frequency or frequencies at which the apparatus mitigates sound propagation.