Fluid Oscillators as Effective Pneumatic Valves or Flow Control Devices

pneumatic valves

Fluid oscillators are pneumatic valves or flow control valve systems based on the bi-stable states of a jet of fluid inside a specially designed flow chamber. Fluid oscillators are mostly found in the aerospace industry and always involve constant improvement in performance and fuel efficiency.

Also called sweeping jet actuators or flip flop oscillators, these flow control fluid oscillators work by being embedded directly into the control surface of an aircraft wing or turbine blade. The whole system then generates spatially oscillating bursts or jets of fluid to improve flow characteristics by enhancing lift, reducing drag, or enhancing heat transfer. 

Recent NASA Improvement

A recent NASA study and development has created a new type of fluid oscillator with a 60% enhanced performance. NASA actually offers two new fluid oscillator designs that solve two key problems and limitations usual with oscillators. First, one oscillator effectively decouples the oscillation frequency from the amplitude. The second design enables synchronisation of an entire array. These new oscillators have no oscillation moving parts (except for the vital pneumatic valves). Synchronisation and decoupling are achieved through internal flow dynamics.

Applications of Fluid Oscillators

As flow control devices, fluid oscillators can be used in the following applications:

  • Aerospace – Used for aircraft and selected types of space vehicles, particularly for mixing and drag reduction, lift enhancement, and separation control.
  • Commercial spa equipment – Improves nozzle performance.
  • Gas turbines – Separation control and heat transfer enhancement.
  • Shipbuilding – Flow control.

Flow Control Technology

Oscillators in general – including the ones developed at NASA – are flow control devices based on novel geometric designs. They have little moving parts and produce spatially oscillating jets.

Decoupling frequency and amplitude

Oscillators in the past were limited since the frequency of oscillation is controlled by input pressure or mass flow rate. Frequency and amplitude or mass flow rate are coupled, limiting control authority over oscillators. The new NASA oscillator design decouples the frequency. The decoupled oscillator delivers high or low mass flow rates without changing frequency.

Synchronising oscillator jet array

Oscillators in the past oscillate randomly. While this is good for mixing enhancement, the new synchronised flow system is more beneficial for active flow control applications. The new synchronisation system also uses far less mechanical and other moving parts.

Master Mac 2000

The importance of flow control valve systems or pneumatic valves in the aerospace industry also shows the importance of valves in all types of industries and applications, whether for general or heavy use. This is why when Master Mac 2000 was established in 1989, as the company grew to become one of Australia’s largest privately-owned process valve and pneumatic component distributors, the company continued to distribute valves of high-quality brands like Univer and Tolomatic. Give Master Mac 2000 a call today at 07 3344 4711 for your valves and other needs. You can also visit their website at https://mastermac2000.com.au/.

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