Hydrodynamic Plane Wave Generator

thingiverse

Here is my version of a Hydrodynamic Plane-Wave Generator as designed by:\r\n\r\nD. M. Harris, J. Quintela, V. Prost, P.-T. Brun, & J. W. M. Bush\r\nDepartment of Mathematics, Massachusetts Institute of Technology, Cambridge, USA\r\nE-mail: pierrethomas.brun@gmail.com\r\n\r\nHere is a link to their design:\r\nhttps://math.mit.edu/~bush/wordpress/wp-content/uploads/2016/09/JOVI-S-20161.pdf\r\n\r\nI basically followed their design with the following changes:\r\n\r\nI used an old Dell laptop charger that I had laying around, which outputs 19.5 volts at 4.62 amps.\r\n\r\nI swapped out the cell phone frequency generator application for a modular frequency generator (purchased from Amazon in kit form as KKmoon XR2206), making it easier to use in public demonstrations.\r\n\r\nThe frequency generator requires a voltage input of 9-12 volts, so I added a voltage buck module (available on Amazon - any model will do, but I got one with a voltage display) to reduce the voltage to 10.0 volts.\r\n\r\nFor personal use, a cell phone with the frequency generator application should work without needing the frequency generator and buck module.\r\n\r\nI chose the amplifier model "AOSHIKE TPA3116 DC 12-24v 100W Subwoofer Amplifier Board" from Amazon, which also powers the light strip.\r\n\r\nThe speaker is a 6.5" 8 ohm 30 watt unit scavenged from a friend - thanks Camilo!\r\n\r\nI replaced silicon oil with linseed oil, easy to obtain and suitable for this application; I plan to experiment with other oils as well.\r\n\r\nFor the oil dish, I used Amazon's "100 mm Glass Petri Dish, Autoclavable Tissue Culture Plate, Borosilicate Glass, Pack of 2" by Chang Bioscience.\r\n\r\nThe light strip is a high-brightness LED strip from Amazon - LEDMO LED Strip Lights, SMD 2835 Non-Waterproof LED Strip DC12V 600LEDs 16.4Ft 6000K 15Lm/LED High CRI80 LED Light Strips 3 Times Brightness Than SMD3528 LED Strip White.\r\n\r\nOne amplifier output powers the speaker, while the other powers the light strip.\r\n\r\nThe strobe effect from the light strip effectively stops the bouncing motion of the oil drop or shows it in slow motion - is it magic or science?\r\n\r\nInteresting phenomena occur both above and below the Faraday threshold; this setup may be used as an analogy to demonstrate Talbot effects, quantum effects, etc., but it's also just fun to bounce a drop of oil on an oil surface!\r\n\r\nThe OpenScad file includes all the parts and electronic components - use comments to control what gets displayed or printed.\r\n\r\nAdjust the box height for your speaker.\r\n\r\nI started working on a "cover" for the petri dish, using 3D printing to create a cylinder with an O-ring seal for transport or storage - not complete yet.\r\n\r\nAll electronics are mounted on the outside of the box; I chose this configuration for educational value and to avoid overheating components during extended use.\r\n\r\nComponents remain cool to the touch after running it for a few hours at a time, but it may be possible to mount them inside the box with only knobs protruding - the box might need to be slightly larger for this setup.\r\n\r\nI spray painted the bottom of the petri dish dark brown (black would have been better) to help see the drops clearly.\r\n\r\nFour small blobs of epoxy (JB Kwik) were used to mount the petri dish to the speaker cone.\r\n\r\nThe speaker was mounted to the bottom of the box using four small blobs of epoxy (JB Kwik).\r\n\r\nA bead of Liquid Nails Small Projects Adhesive was used to mount the light ring to the speaker.\r\n\r\nEnjoy!