Fluidic Oscillator Underwater Sound Attenuation

The patent employs a fluidic oscillator to generate pulsating air flows instead of continuous pressurized air flow. The oscillator creates periodic pulses of air that are forced through the hole, generating bubbles at regular intervals. This periodic action allows each pulse to hold a certain amount of air that is weakly dependent on inlet pressure, resulting in uniform bubble sizes while significantly reducing the total amount of pressurized air required compared to continuous flow systems.

The patent changes the flow regime from continuous to pulsating by introducing a fluidic oscillator. This parameter change in the air flow characteristics allows for better control of bubble formation. The pulsating flow creates distinct air pulses that form uniform bubbles, optimizing the bubble size for acoustic energy reflection and absorption while reducing the overall air consumption compared to continuous pressurized air injection.

The fluidic oscillator generates regularly spaced pulsating air flows that create uniform bubbles at consistent intervals. This periodic generation ensures that bubbles are formed with similar sizes and timing, reducing the likelihood of coalescence between bubbles of vastly different sizes. The regular pulsation pattern maintains bubble stability by preventing the chaotic formation conditions that lead to bubble break-up and coalescence.

By transforming the air flow from continuous to pulsating through the fluidic oscillator, the patent achieves better control over bubble formation parameters. The pulsating flow creates consistent pressure conditions during each pulse, leading to uniform bubble sizes that are more stable. This parameter change reduces the sensitivity of bubble characteristics to variations in local conditions, preventing easy coalescence and break-up.

The fluidic oscillator creates periodic pulsating air flows where each pulse is self-contained and holds a certain amount of air. This periodic action results in bubbles of specific, relatively uniform and constant size because each pulse generates a consistent volume of air regardless of moderate variations in inlet pressure or temperature. The oscillating mechanism naturally compensates for supply variations, maintaining bubble size uniformity.

The patent changes the air delivery mode from continuous to pulsating through the fluidic oscillator. This parameter change creates discrete air pulses that form uniform bubbles. The pulsating flow regime makes bubble size less sensitive to variations in supplied air pressure and temperature, as each pulse is defined by the oscillator's geometry and operation rather than solely by supply conditions. This results in more consistent bubble sizes despite environmental variations.

The patent uses a fluidic oscillator, which is a pneumatic device that utilizes fluid dynamics principles to generate pulsating flows. This pneumatic component replaces what would otherwise require complex mechanical valves, motors, or control systems. By leveraging pneumatic principles, the oscillator adds minimal complexity while effectively generating the pulsating air flows needed for optimal bubble formation and sound attenuation.

The fluidic oscillator is a self-regulating device that automatically generates pulsating air flows based on the incoming air supply without requiring external control systems. It uses the air flow itself to drive the oscillation mechanism, eliminating the need for additional sensors, controllers, or power sources. This self-service characteristic minimizes the overall device complexity while achieving the goal of generating uniform, stable bubbles for effective sound attenuation.