Cavitation aggressive intensity greatly enhanced using pressure at bubble collapse region

May 2, 2016
This image shows hydrodynamic cavitation through a venturi tube. Credit: Hitoshi Soyama

Researchers at Tohoku University are developing a method to improve the aggressive intensity of cavitation without the need to increase the input power.

Cavitation - the formation, growth and subsequent collapse of microbubbles - produces high, localized energy which can be used in for treating water and the pretreatment of biomass.

The research team found that the conventional method of applying ultrasonic energy was not strong enough, so they proposed using hydrodynamic cavitation instead.

In the proposed method, test water is passed through a constriction tube. Hydrodynamic cavitation is then produced by the decrease of pressure due to the increase of flow velocity.

The team found that the aggressive intensity of hydrodynamic cavitation was optimized with an increase of pressure at the bubble collapse region.

Although most researchers believe that an enlarged cavitation area produces aggressive intensity, by contrast, it seems a rise in aggressive intensity can occur with a reduced cavitation area. In the research experiments, the size of the cavitating region was reduced by varying the upstream and downstream pressures.

Although the developing region of hydrodynamic cavitation is decreased with an increase of pressure at bubble collapse region p2, the acoustic power is increased with the pressure and it has a peak at certain pressure. Credit: Hitoshi Soyama

The team has demonstrated the enhancement of cavitation aggressive intensity by a factor of about 100 by optimizing pressure at the region, measuring acoustic power at cavitation bubble collapse, and luminescence as a function of the pressure.

This method can be useful for practical applications, as it does not need additional power, but the aggressive intensity can be increased simply by controlling a valve downstream to the cavitating region.

Explore further: Improving biorefineries with bubbles

More information: H. Soyama et al, Enhancing the aggressive intensity of hydrodynamic cavitation through a Venturi tube by increasing the pressure in the region where the bubbles collapse, AIP Advances (2016). DOI: 10.1063/1.4947572

Related Stories

Improving biorefineries with bubbles

March 1, 2016

A team of researchers from Japan's Tohoku University has developed a new method for the pretreatment of organic material, or "biomass", which could lead to more efficient production of biofuels and biochemicals.

Cavitation bubbles bursting with cleaning power

January 12, 2016

It's easy to think of soap suds when one thinks of bubbles, but these bubbles can clean without chemicals. These are cavitation bubbles, which are created when air is churned up in water. And what researchers are learning ...

Computer simulation reveals new effect of cavitation

March 28, 2016

Researchers have discovered a so far unknown formation mechanism of cavitation bubbles by means of a model calculation. In the Science Advances journal, they describe how oil-repellent and oil-attracting surfaces influence ...

Seeing sound in a new light

November 24, 2011

The National Physical Laboratory Acoustics team has been investigating acoustic cavitation – the formation and implosion of micro cavities, or bubbles, in a liquid caused by the extreme pressure variations of high intensity ...

Recommended for you

Two teams independently test Tomonaga–Luttinger theory

October 20, 2017

(Phys.org)—Two teams of researchers working independently of one another have found ways to test aspects of the Tomonaga–Luttinger theory that describes interacting quantum particles in 1-D ensembles in a Tomonaga–Luttinger ...

Using optical chaos to control the momentum of light

October 19, 2017

Integrated photonic circuits, which rely on light rather than electrons to move information, promise to revolutionize communications, sensing and data processing. But controlling and moving light poses serious challenges. ...

Black butterfly wings offer a model for better solar cells

October 19, 2017

(Phys.org)—A team of researchers with California Institute of Technology and the Karlsruh Institute of Technology has improved the efficiency of thin film solar cells by mimicking the architecture of rose butterfly wings. ...

Terahertz spectroscopy goes nano

October 19, 2017

Brown University researchers have demonstrated a way to bring a powerful form of spectroscopy—a technique used to study a wide variety of materials—into the nano-world.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.