Hi everyone, I’m new to the forum, I hope this is not breaking any rules.
I am trying to create a micro-pump using the vibrations of the underside of a piezoelectric buzzer as a diaphragm to move fluid. It’s based off of this post: https://3dprintingzoom.com/china-3d-printing-prototypes-for-valveless-piezoelectric-pumps/
The pump does not use an active valve, instead it uses “bluff bodies”, which are hemispheres that provide more resistance to flow in one direction as opposed to the other, meaning theoretically that more fluid moves in one direction as opposed to the other.
Here’s the setup: The body of the pump is 3D printed, and the piezo disc is driven by a TI DRV8662 driver using an external PWM signal to control the frequency and amplitude of the driving signal. The driving signal is around 130V max p-p and resonance is achieved around 60-70 Hz as well as around 1.6 kHz.
The problem is that while I’m getting resonance of the fluid in the pump, the fluid is moving back and forth an equal amount, meaning no net displacement of the fluid. In other words, the bluff bodies are not working as a valve as intended.
I have attached a picture of the CAD model of the bluff bodies, and a video of achieved resonance . Please let me know if you have any ideas as to why the set up isn’t working as intended or if you have any alternative suggestions of valves etc.