If you’ve ever squeezed honey or syrup out of a bottle, you may have noticed that the thick, sticky liquid does a curious thing when it’s poured – it coils, like a snake or a rope. You may not have thought anything much about the shape your condiments were making at the time, but it turns out that this coiling behavior is a little-understood phenomenon in physics. The liquid rope coil effect, as it’s called, is mesmerizing to watch, especially in slow motion, as you can see below:
Melted plastic behaves much like a viscous liquid when it’s extruded through a 3D printer; you’ve probably seen the liquid rope coil effect yourself to some extent during a print job gone wrong. Understanding the physics of this behavior is more important than you might expect, especially when it comes to the use of 3D printers in space, and how microgravity affects them.
Ilersich, along with fellow University of Toronto engineering students Neell Young, Caulan Rupke, and Michael Lawee, is part of Team AVAIL (Analyzing Viscosity and Inertia in Liquids), which is one of four teams chosen to participate in the Canadian Reduced Gravity Experiment Design Challenge (CAN-RGX), supported by the National Research Council and the Canadian Space Agency. (Team AVAIL is one of two teams studying 3D printing as part of the experiment.) Experiments designed by the four teams will be carried on a Falcon-20 Research Aircraft, a jet designed for parabolic flights that simulate a reduced gravity environment.
“We were surprised that [the liquid rope coil effect] hasn’t been given the full treatment yet in the scientific literature,” said University of Toronto engineering student Andrew Ilersich. “It turns out to be a very complex process to describe mathematically.”
The challenge required the teams to build experiments that fit inside a 50 x 50 x 50 cm box. Team AVAIL built a system that controls the flow of a viscous liquid (corn syrup, in this case) through 15 different nozzles. A video camera is mounted inside the box to record the rope coiling behavior of the liquid in microgravity, and custom-built software will analyze the behavior. The system was designed to simulate the behavior of a 3D printer.
Those applications include 3D printing in space, which would allow astronauts to fabricate hand and medical tools and other items on an as-needed basis rather than bringing loads of equipment on missions, which isn’t often feasible. A better understanding of the liquid rope coil behavior could lead to new applications here on Earth, too; a reliable mathematical model could be used to control the behavior and use it to fabricate new materials out of coils woven together. Those materials could have carefully controlled properties such as strength and flexibility, and could include porous materials for tissue engineering, filtration and catalysis.
“We think our project was chosen because of its novelty and its applications,” said Ilersich.
“This project has been an exciting introduction to the research process,” said Ilersich. “I’ll draw upon everything I learned here when I do my undergraduate and graduate theses, and potentially in a research career after I graduate.”
Team AVAIL is in Ottawa this week for three days of training and the experimental flight. They will make 12-14 parabolic flights, each about 20 seconds in duration, today, July 25th.
Ready to fly pic.twitter.com/7GPE2dTc8r
— CAN-RGX Team Avail (@CAN_RGX_AVAIL) July 25, 2017
Discuss in the Team AVAIL forum at 3DPB.com.[Source: University of Toronto]