Visualizing Ultrasound with Schlieren Optics Part II

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Visualizing Ultrasound with Schlieren Optics Part II

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Harvard Natural Sciences Lecture Demonstrations

6 жыл бұрын

Part 2 of 3. We use our strobing schlieren system to look at diffraction and standing wave patterns in air created by an ultrasonic transducer (driven at 28 kHz) and a reflecting glass plate.
More information about our schlieren optics set-up and how it works can be found on our website: sciencedemonst...
Safety Note: Although 28 kHz is beyond the range of human hearing, ear protection should be worn whenever attempting this experiment to avoid damaging vibrations in parts of the ear. Any high-pitched whines you hear in this video are not dangerous.

Пікірлер: 21

@whosscruffylookin95 3 жыл бұрын

this series deserves more views. wonderful explanation and a nice setup

@NatSciDemos 3 жыл бұрын

Glad you liked it!

@glikar1 4 жыл бұрын

Absolutely beautiful demonstration!

@fjs1111 2 жыл бұрын

Love this professor, thank you!

@poweronegaming3681 2 жыл бұрын

That's amazing 🔥

@purplepick5388 3 жыл бұрын

mindboggling !

@sahinmcelen 3 жыл бұрын

Thanks for the answers I already dreamed

@HumbleBasse 3 жыл бұрын

wonderful ;) good job

@IronMoe 2 жыл бұрын

please make more videos like this

@farhad_24 Ай бұрын

Can you apply this setup for visualizing electrical breakdown in air?

@Stuff924 3 жыл бұрын

I would like to see interference patterns of different frequencies

@mankap196 3 жыл бұрын

Excellent presentation! But wouldn't the standing wave be visible to us, even without the strobing light?

@wolfgangrueckner7151 3 жыл бұрын

correct

@AdityaMehendale 6 жыл бұрын

Aren't you worried about tissue/bone-damage when you touch the transducer with your finger? (Is the power really low?) Cool demo!

@wolfgangrueckner7151 6 жыл бұрын

The power is very low (8 watts).

@DejanSpasovski 4 жыл бұрын

The wavelenght in the video at 2:30 does not match the markings of the ruler. we should see 6 approx. 6 full wavelenghts but we count almost 10. How do you explain this. Is it a byproduct of the strobe maybe? Also observing the waves in the lower right part of the picture where we see two full wavelenghts per 1.2cm. Any thoughts?

@wolfgangrueckner7151 4 жыл бұрын

This is a standing wave (as opposed to a traveling wave) and a bright band occurs every half wavelength.

@DejanSpasovski 4 жыл бұрын

@@wolfgangrueckner7151 Oh..yes, my bad. That makes sense now! Thanks for your kind reply. Really amazing demonstrations.

@DerptyDerptyDUM 3 жыл бұрын

😮

@samjongman929 5 жыл бұрын

could you maybe tell me something more about how you setup the transducer?

@wolfgangrueckner7151 5 жыл бұрын

The ultrasonic waves are generated by a 28 kHz transducer designed for ultrasonic cleaning baths. These are typically driven by a push-pull oscillator specially designed for this application. Many are controlled by an Arduino microcontroller. Ours is driven harmonically, powered by a Samson Servo 120 audio power amplifier. The input signal comes from a sine wave function generator. A home-made impedance matching transformer couples the 8-ohm output of the audio power amplifier to the ultrasonic transducer.