Home study projects of complex fluids in anyone’s kitchen, using easily available equipment and substances —


Though the COVID-19 pandemic induced many disruptions within the academic system, it additionally led to some stunning advantages.

In Physics of Fluids, by AIP Publishing, scientists from the College of Illinois at Urbana-Champaign describe their work with college students on an at-home examine of complicated fluid habits. The course covers a sort of physics referred to as rheology, which is used to check the way in which non-Newtonian liquids or semisolid substances movement.

Newtonian fluids have a relentless viscosity, however non-Newtonian fluids can deform when pressure is utilized. Typically, they reply with plastic movement. Easy rheometric measurements will be carried out in anybody’s residence to measure portions similar to viscoelasticity, shear thinning, and different rheological properties.

“We initially known as the mission Shelter-in-Place Rheometry because of the acute nature of the COVID-19 pandemic and shelter-in-place guidelines,” stated Randy Ewoldt, the professor concerned in growing the course. “However we realized that the thought is extra common and have since taken to calling it do-it-yourself rheometry.”

The initiatives assigned to the scholars had two components: gathering qualitative visible proof of rheological properties and taking quantitative measurements. The scholars checked for 4 behaviors: shear thinning viscosity, viscoelasticity, shear regular stress distinction, and extensional viscosity.

Even with out entry to laboratory rheometers, the scholars developed artistic and distinctive methods to hold out their measurements. They studied quite a lot of frequent substances, together with buttercream frosting, toothpaste, yogurt, peanut butter, mayonnaise, egg whites, and lots of different substances accessible of their properties.

One pupil, Ignasius Anugraha, developed a compression squeeze movement evaluation to check buttercream frosting. Anugraha positioned the frosting between two cardboard discs and subjected it to a pressure by stacking ramekins stuffed with water atop the discs.

The frosting was capable of assist the load of the water till a important worth was reached, at which level the frosting collapsed on one aspect and squeezed out. Utilizing equations involving the load of the water, Anugraha was capable of measure a amount referred to as the yield stress.

One other pupil, Max Friestad, devised an experiment to check a habits referred to as gravity-driven filament stretching. Friestad suspended a tube of toothpaste vertically and gently squeezed it, expelling a dollop of toothpaste that slowly prolonged, stretching downward. Utilizing a cellphone with a high-speed frame-rate digital camera, Friestad was capable of take measurements and calculate the extensional viscosity.

The course was so profitable that the college proceed to supply it, each in-person and on-line.

“We’re at the moment engaged on a assessment of strategies which we imagine shall be helpful not just for coursework and instruction but in addition for analysis and technical communication,” stated M. Tanver Hossain.

Story Supply:

Supplies supplied by American Institute of Physics. Word: Content material could also be edited for type and size.