Hydrodynamic cavitation via an orifice plate

[funcentropy]

Hello all,
I'm trying to induce hydrodynamic cavitation in a water filled vessel at STP using a high pressure piston pump and an orifice plate.

Does anyone have any knowledge of estimation methods for the relationship between pressure drop, orifice area and cavitation intensity? Clearly the fluid situation isn't a simple one, but I am mainly concerned with determining what threshold the system must cross in order to induce cavitation.

Also, could anyone recommend an easy way to characterize the presence and intensity of the cavitation? I was thinking about using a pH meter to detect the increase in autoprotolysis of the water. Any thoughts on whether or not a standard bench pH meter would be sensitive enough?

Clearly, I'm pretty green on cavitation. While I've found many research papers on Ultrasonic Cavitation, direction to a reference source on Hydrodynamic Cavitation would be greatly appreciated.

Thanks

 

[FredGarvin]

Well, the easiest thing is to make sure the orifice is small enough that the pressure drop is large enough to bring the absolute pressure below the fluid's vapor pressure. That may be easier said than done since you'll probably experience choked flow before you get there.

I have no idea how cavitation is described or measured. You'll have to do some research on that one. I would imagine it would have something to do with being able to measure bubble size and having that coupled with the pressure of the surrounding fluid.

 

[oswaler]

for your question about hydrodynamic cavitation via an orifice plate. Hydrodynamic cavitation is a complex phenomenon that occurs when a liquid is subjected to a sudden decrease in pressure, such as through an orifice plate. This creates small bubbles or voids in the liquid, which then rapidly collapse and generate high temperatures and pressures. This process can be used for various applications, such as wastewater treatment and mixing processes.

In terms of estimating the relationship between pressure drop, orifice area, and cavitation intensity, there are various models and equations that can be used. One commonly used method is the Rayleigh-Plesset equation, which relates the bubble collapse pressure to the pressure drop and orifice size. However, it is important to note that the exact relationship can vary depending on the specific conditions and properties of the liquid being used.

As for characterizing the presence and intensity of cavitation, there are a few methods that can be used. One approach is to use a high-speed camera to visually observe and measure the bubble collapse. Another method is to use acoustic sensors to detect and measure the acoustic emissions produced by the collapsing bubbles. Using a pH meter to measure the increase in autoprotolysis of water can also be effective, but it may not be sensitive enough to accurately measure the intensity of cavitation. It may be helpful to conduct some experiments to determine the best method for your specific setup and conditions.

In terms of references, there are many research papers and articles available on hydrodynamic cavitation. Some good sources to start with include "Hydrodynamic Cavitation: A Review" by Gogate and Pandit, and "Hydrodynamic Cavitation: Fundamentals, Applications and Future Prospects" by Badve et al. Additionally, there are several textbooks and handbooks on cavitation that may be helpful in understanding the principles and applications of this phenomenon.

I hope this information helps in your research on hydrodynamic cavitation. Best of luck in your experiments and studies!