Using an AeroPress Coffee Brewer to Teach Fluid Mechanics

Fluid mechanics is a cornerstone of chemical engineering, but courses in fluid mechanics typically require students to have prior knowledge of advanced mathematical and

physical concepts. The steep prerequisites complicate efforts to create entry-level, introductory fluid mechanics pedagogy for engineering or non-engineering students. Here, we describe a laboratory module called “Pressure Driven Flow through Coffee Grounds”, which is offered as a part of a general education, no-prerequisite class titled “The Design of Coffee: An Introduction to Chemical Engineering”, a course which regularly enrolls over 500 students each academic quarter at the University of California Davis. In this laboratory session, students perform hands-on experiments with an “AeroPress” brewer that allows students to simultaneously measure the manually applied pressure difference and the resulting flow rate of brewed coffee. After the experiment, students are expected to have learned how to: (1) relate the concepts of pressure and flow rate using Darcy’s Law, (2) assess how the flow rate affects the strength and quantity of the brewed coffee, and (3) clearly communicate technical data via graphs. We measured gains in achievement of these first two learning objectives using quizzes administered before and after the lab session, and we assessed the third learning objective by comparisons of submitted graphs versus a standardized rubric. We present statistical analyses of achievement in each category, and we further discuss how the AeroPress module can be incorporated into existing first-year classes tailored to different cohorts of students.