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Ultra high speed cameras that record fractions of moments

We usually see these used in movies and other broadcasts.

However, recently, these camera have become an absolute necessity in the study of flow within water or air.

The Science of Flow, invisible to the naked eye, covered by journalist Byung San Son.

Report

Gas disperses as a match is struck, lighting it up and a vortex of air puts it out upon blowing on it.

The reason visualization of movement of gases, invisible to our naked eye, is possible is due to a special imaging technique called “Schlieren”.

By shining light through the gases, the different refractive indexes of gases of different densities produce bright and dark spots allowing us to capture the movement of invisible gases.

The video shows a ray of light hitting a round bubble and dispersing at 20 thousand frames per second, taken by the ultra highspeed camera.

By recording the same video at 10 million frames per second, we can see the instant the bubble disperses like a mist.

Using ultra high speed camera to capture almost instantaneous movement of water and air allows the development of new technology through this research.

Professor Ho-Young Kim/SNU Mechanical and Aerospace Engineering

"Innovative ideas to reduce fuel usage in car engine designs also come from such visibility researches."

Recently, another national researcher analyzed the instant when a flag hits a wall using a high speed camera to find the optimal conditions for generating electricity through friction.

Researcher Jeongsu Lee/ SNU Mechanical and Aerospace Engineering

"we’re were differing variables such as wind speed or the gap between the flag’s length and the plate on which the flag would hit."

Flow Dynamics that capture instants are also being used to develop bio-mimicry robots that mimic the flapping of a bird’s wings.

MBC News Byung San Son

(Journalist Byung San Son san@mbc.co.kr )

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