As Rohit Velankar, a senior at Fox Chapel Area High School, pours juice into a glass, he notices the rhythmic “glug, glug, glug” flexing the walls of the carton. This simple observation sparked his curiosity and led him to wonder if a container’s elasticity influences the way its fluid drains. What began as a science fair project evolved into a collaborative research endeavor with his father, Sachin Velankar, a professor of chemical and petroleum engineering at the University of Pittsburgh Swanson School of Engineering.
Setting up an experiment in their family’s basement, the Velankars delved into the intricate relationship between container design and fluid dynamics. Their collaborative efforts culminated in the publication of their findings in the prestigious journal Physics of Fluids, marking the beginning of a new chapter in their scientific journey as father and son. Sachin Velankar shared, “I became quite invested in the project myself as a scientist. We were committed to seeing it through and uncovering the underlying principles.”
Rohit’s initial experiments revealed that deli containers with rubber lids emptied faster than those with plastic lids, shedding light on the phenomenon of “glugging.” According to Velankar, “Glugging occurs when the exiting fluid reduces the pressure within the container, leading to intermittent flow. Flexible containers, such as IV fluid bags or boxed wine, exhibit smoother fluid dispensing due to their elasticity.” This discovery prompted the Velankars to explore the impact of container flexibility on fluid drainage further.
To investigate this phenomenon, the Velankars designed acrylic bottles with rubber lids using resources available at Fox Chapel Area High School’s makerspace. By incorporating sensors near the bottle’s bottom hole to measure pressure oscillations during drainage, they were able to simulate different levels of flexibility. Their experiments confirmed that flexible bottles not only drain faster but also exhibit larger, less frequent “glugs,” providing valuable insights into optimal container design for efficient fluid dispensing.
Through their collaborative research, Rohit and Sachin Velankar have not only deepened their understanding of fluid dynamics but also highlighted the importance of interdisciplinary exploration and innovative problem-solving. Their journey serves as a testament to the power of curiosity, teamwork, and perseverance in scientific inquiry, inspiring future generations to embrace the wonders of discovery.