The Ruben's Tube is a demonstration of standing waves through flames. A tube has holes cut into the top in a line. one end of the tub is sealed solid while the other has a rubber material that vibrates when a speaker is near it, creating pressure differentials inside the pipe, and moving the gas that is pumped into the tube to create flames. This creates a wave patter in the flames on top of the tube.
The Materials for this project are easily found at a local hardware store. the materials are:
These are the instruction on how to construct the Ruben's Tube:
Building of version 1.0 proved difficult. As the first attempt at creating the Ruben's Tube, I had to work out the design and learn the construction steps for the first time. To start, the metal duct pipe was substituted for a black ABS plastic material,
as PVC pipes and metal duct pipes to the length i was looking for were unavailable. I found that i had used the incorrect drill bit to make a hole for the gas and had to seal the pipe with duct tape. I later also discovered the propane gas line i
had used had bad ends for my purposes. The mae threaded end that i screwed into the pipe-cap was meant to go into the regulator, and there was nothing now to connect it. Future reference , buy a male to male adapter to create solid connection.
Now that my propane line was ineffective, i had to tape the end closed, and proceeded to drill a hole for my barb MIP adapter. I only attached one to the end of the pipe, and used a full length of 20 ft. of latex hose to connect to the propane
tank. I jury rigged the tank to the line with the second barb MIP connecor a washer, and a rubber o-ring gasket. After initiating a flow of propane to the Ruben Tube, i had waited for flames to ignite from the lighter. My friend assited with gas flow
at the end of the 20 ft line for safety.
After a few minuets of nothing happening, i worried there was a leak somewhere in the system. After switching spots with my partner, i increased the gas flow to full open on the tank, and after a
few more seconds the pipe hole finally lit. After some math i discovered that the system was way to large to be fed by a single line, 20 ft in distance from tank to system. a total area of 141.4 cubic feet of space was being filed by a single 20 ft
long by 1/4 in. diameter gas line. This proved ineffective.
after the system finally built enough pressure to sustain flames of decent height, black smoke began to appear, at which point it was discovered that the black ABS pipe was melting
from the flame. I worried that flashback might occur, comprimising the entire system due to this literal meltdown. At this point, i donned my gas mask, and smothered the device with a Dry-Chemical fire exstinguisher.
Finally, Version 1.0 will be officialy abandoned. I shall attempt again with metal duct pipe, although smaller and possibly harder to drill for Version 2.0.
V2.0 proved incredibly more successful. Design the second time around was much easier since it was known. The used material for this was a metal duct pipe instead of ABS platic piping. The metal duct was smaller with a diameter of 2 inches, and a length of 30, half the origional length. Most of the construction steps were the same os V1.0. It took longer to drill into the metal duct than it did the ABS pipe.
Test of the Lab Gas intake valves instead of propane proved to be a monumental improvement. With the better flow of gas from the nozzles in the lab, we had better control over flame height. In the beginning, we tested with full valve, giving the maximum ammount of gas flow available. After testing and measuring different tones, we had found that by decreasing the flow rate and using a smaller flame, changes in tone and waves were much more easily seen. The end result was the consensus that for best results, use a low gas flow to produce about 2-3cm high flames for the best results.
This was the first version melting. Black smoke can be seen from the plastic melting:
This is the operation of build V2.0:
This is a problem found in build V2.0:
Here are some video demonstrations of the Rubens Tube with different forms of music:
Dubstep, and other heavy base tones prove to show the greatest change in waves and have the best effects on the Rubens Tube. High Treble songs provide higher pitches which are too finely tuned to be visualized with this version of a Rubens Tube.
500Hz Wave:
Frequency | Distance from Nodes |
---|---|
378Hz | 27cm |
404Hz | 28cm |
440Hz | 17.5cm |
450Hz | 22cm |
460Hz | 23cm |
500Hz | 24.5cm |
514Hz | 23.5cm |
533Hz | 29cm |
550Hz | 46cm |
The graph demonstrates our results from measuring the distance between nodes in relation to the frequency. The bars represent our error margin in measuring the distance, as it was done by eye instead of avanced methods. Our error bars are +/- 5cm
The Rubens Tube proved successful in creating standing waves with the produced frequencies. By looking at the data table you can notice there is a trend that as we increased the frequency, then the distance between nodes also increased. This was also demonstrated visually with my graph. On the graph, you will notice bars above and below my data points. These are the error bars. The error bars demonstrate the range of error i had when measuring the distance between nodes. In future experiements, a measuring device should be used that is more accurate than just using a ruler and eye-balling it. The graph trend line helps visually confirm the previous notion that as our frequency increased, the distance between our nodes also increased.