Application Cases

Experiment Name: Application of Power Amplifiers in Research on the Efficient Mixing Mechanism of Synthetic Jets

Experimental Content:
Synthetic jet is a novel active flow control technology. Its main working principle involves using a vibrating diaphragm or piston to periodically blow/suck fluid, forming vortex rings at the orifice. These vortex rings propagate downstream under the effect of self-induced velocity and merge to form a jet. Synthetic jets have been applied in numerous flow control fields, including mixing enhancement, heat transfer enhancement, and flow separation control. This experiment investigates the efficient mixing mechanism of synthetic jets from the perspective of instantaneous flow structure evolution using Particle Image Velocimetry (PIV) technology.

Research Direction: Efficient Mixing Mechanism of Synthetic Jets

Testing Equipment: Signal generator, ATA-214 high-voltage amplifier, synthetic jet actuator, high-speed camera, dual-pulse laser, etc.

Experimental Procedure:
The signal generator produces a sinusoidal voltage signal, which is amplified by the Aigtek ATA-214 voltage amplifier to drive the piezoelectric ceramic diaphragm of the synthetic jet actuator (see Figure 1) to vibrate. This causes the synthetic jet actuator to periodically blow and suck the surrounding air, generating a synthetic jet. By varying the driving frequency and voltage, a hot-wire anemometer probe is used to measure the peak air velocity at the orifice to obtain the frequency and voltage characteristics of the synthetic jet actuator (see Figure 3). After calibrating the synthetic jet actuator, Particle Image Velocimetry (PIV) experiments are conducted using a high-speed camera and a dual-pulse laser to acquire flow field data, aiming to study the efficient mixing mechanism of synthetic jets.

Experimental Results:
The synthetic jet actuator exhibits resonance near 500 Hz and 1200 Hz, where the orifice velocity reaches its peak (see Figure 3a). Within a certain voltage range, the orifice velocity increases linearly with increasing voltage (see Figure 3b). Based on the frequency and voltage characteristics of the synthetic jet actuator, synthetic jets with specific frequencies and velocities can be generated by adjusting the driving frequency and voltage. The flow field is then studied through PIV experiments (see Figure 4b).

Figure: ATA-214 High-Voltage Amplifier Specifications and Parameters