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A new type of standing wave visualization device

Description: We designed this device to achieve the goal of the visualization of standing waves by reducing the risk of using flames in Rubens tubes, and find out the effects of different sound frequency and pressure on smoke. We put the LED light into the tube body which has small holes. Then put a speaker and a fog machine on the sides of the tube, turn on the fog machine and speaker, observe the flowing of the smoke from the device under different music. If the sound wave of a fixed frequency is introduced into the tube, a standing wave will be formed. When the pressure of the standing wave is the highest, the speed of the smoke from the small hole will be the fastest. In con, when the standing wave pressure is small, the amount and rate of smoke sprayed from the small holes will be less and slow. Conclusion 1.Colour The red light has the longest wavelength in visible light, therefore the use of red light can make the smoke spraying easier to observe and also enhance the visualization of stan

1. Research background: The Rubens Tube is an ancient physical device invented by German physicist Heinrich Rubens in 1905, which visually demonstrates the relationship between sound waves and sound pressure in the form of flames. Simply put, it allows us to see the fluctuation of the sound through the change of the flame, which has a very gorgeous visual effect. 2. Main features: The use of LED color changing lights and fog machine to produce visual effects of different colors, which can reduce the discolouration of the lamp. The original luminescence is three primary color LEDs. When the LED is illuminated, it can change color, yellow, purple, and cyan (such as red and two LEDs) and emit purple light. ); If the red, green, and blue LEDs are lit at the same time, it will produce white light. By observing the influence of light pressure and frequency on smoke, the visualization of standing waves is realized at the same time. 3. Structure composition: Use a cutting tool to cut the bottom of each potato chip pot so that the smoke can pass through. Glue the potato chip can into a long tube, use hot melt glue to bond and fill the gap, to ensure that there is no light leakage or smoke leakage. Along a straight line on the long pipe, open several small holes of the same size at the same interval. Fix the LED light strip on the bottom of the tube, and the LED bulb is facing the small hole upward. Place speakers and humidifiers on both sides of the nozzle. Turn on the humidifier and loudspeaker, and observe the changes of smoke in different sound frequencies, amplitudes, and colors. 4. Main purpose: The visual effect of this equipment is mainly composed of LED light strips and humidifiers. LED color-changing lights are suitable for family birthday parties, holiday parties, and Chinese New Year, adding joy to the festival. It can also be used in entertainment venues and as advertising lights, etc. It is very aesthetic in design, so can also be used for various stage performances of star artists to enrich the picture. Furthermore, it can be used for demonstration in class or other teaching activities. Because there is no need to use fire, the safety is greatly improved, and the abstract standing wave can be visualized to make it easier for people to understand. 5. Testing quality: When the sound wave frequency is increased to about 700 Hz, resonant will occur in the tube body obviously, and the periodic phenomenon of smoke tends to disappear. We can judged that the natural frequency of the tube is about 700 Hz. When the input sound wave frequency is equal to its natural frequency, a mechanical resonance phenomenon occurred, and the Rubens tube exhibited a large-amplitude vibration, which was no longer a stable system. The distribution of smoke emitted by the fog machine tends to be uniform, and the periodic change of the height of the smoke emitted by the small holes is no longer obvious. 6. Conclusion (1) Color During the test, we tried to observe the different phenomena of smoke with different colors. If we want to achieve the clearest and most obvious rendering effect, red color will be the best choice. Red is one of the three primary colors. It has the longest wavelength and the lowest frequency in visible light. Light scattering refers to the phenomenon that part of the light changes direction in many ways when light passes through a dusty medium. (2) Sound wave Sound waves are usually a combination of sine plane waves, which include frequency and wavelength. The higher the pitch, the higher the frequency and the shorter the wavelength. The larger the wavelength, the wavenumber of the standing wave will decrease. Therefore, when the loudspeaker plays high-pitched music, the effect is better than the low-pitched music. When the input frequency is too high, the tube body will produce obvious resonance phenomenon. The tube has a large amplitude vibration and is no longer a stable system. The pressure distrib

Organisation: The Affiliated School of the University of Macau

Innovator(s): Leng Ka Hei, Vu Wei Ian, Chong Ka Sin, Leong Chi Wang

Category: Environment

Country: Macau SAR

Gold Award