“Flipped Classroom” Energizes Computational Fluid Dynamics Course



“Two . . . one . . . zero. Change!”

Clutching an iPhone, Assistant Professor Lorena Barba (ME) works a brightly lit computer lab at the Photonics Center like a Hollywood movie director, cueing her ENG ME 702 – Computational Fluid Dynamics (CFD) students to take their places on the set of what she calls the “Navier-Stokes Speed Dating Game.” As the action unfolds, five of the 10 graduate students and seniors in attendance—selected at random by an app on Barba’s iPhone—remain at their workstations and display their software solutions to a physics problem using the classic equations that describe fluid motion. The other five pair off with a succession of three-minute “dates” at each workstation, compare notes, and select the date with the most impressive solution. The winning programmer then projects his code and graphical results on a whiteboard at the front of the room, sparking a lively discussion about its merits.

The scene departs dramatically from what took place in last spring’s version of the course, when Barba delivered a lecture on the same topic, deriving equations on the whiteboard as students mainly listened and took notes. That’s because this year she decided to “flip the class,” posting videos of lectures online for home study and using class time to guide highly interactive, collaborative problem-solving sessions that clarify concepts presented in the lecture—i.e., the “homework.” Rather than deliver information from on high, she meanders through the

Barba guides a discussion in which ME master's student Yunshen Cai (left) questions ME PhD student Andrew Wixom (far right) on his interpretation of 3D graphs displayed on a nearby whiteboard. Most of the class eventually joins in.

room, offering an occasional leading question to help a student get unstuck, or facilitating a conversation about the relative advantages of different approaches to the problem at hand.


From Lecture to Workshop

“Creating an active and engaged learning environment is automatic when flipping a class, and with today’s technology for creating multimedia learning materials, it can be done without losing any of the content,” maintains Barba, who made the switch by editing 40 hours of lecture videos that she had already recorded and posted on iTunes U for students in previous incarnations of the CFD course. “In fact, it is the perfect use of technology for education.”

It takes more than technology, however, to implement a flipped classroom successfully, she observes.

“The challenge of the flipped model, I have found, is designing the class activities by which the students are led to discover the important concepts, and explain them to each other. During these activities, the instructor can walk among the students giving them personalized attention, sometimes giving a tip or asking a question.”

While the flipped classroom strategy has been around for more than five years, the widespread availability of online video technology has recently accelerated its adoption in schools and colleges across the globe. Also driving its use is a growing body of empirical studies that underscore the ineffectiveness of the traditional lecture. Informed by these studies, a recent President’s Council of Advisors on Science and Technology report concluded that flipping the classroom, active learning and other more dynamic teaching methods are essential to producing sufficient numbers of science, technology, engineering and mathematics (STEM) graduates to maintain U.S. preeminence in STEM fields.


Upgrading the Learning Experience

For Barba’s students, the flipped classroom has not only captivated their attention, but also deepened their command of the subject matter.

“Class meetings are active, engaging, and encourage cooperative learning,” said Brad Garner, a LEAP student pursuing an MEng degree in mechanical engineering. “Watching condensed versions of traditional lectures at home allows me to reinforce the concepts demonstrated in class without sacrificing the ability to ask questions of Professor Barba or my classmates.”

“The biggest upside to the ‘flipped classroom’ concept is that it provides a structured platform for peer-to-peer learning; every class is like a study group,” added Andrew Wixom, a first-year PhD student in mechanical engineering. “In our class, everyone helps out and the coding projects feel almost like a collaborative effort.”

Barba credits the approach for improving student performance.

“Last time, students usually had a bug or more in their code during their final presentations and never fixed them afterwards,” she recalls. “This time, nearly all are discovering and correcting their errors way before their presentations. Nearly everyone’s code works, leading to much more relaxed, creative presentations.”


A Rising Tide of Innovative Education at ENG

The flipped CFD course is one of a growing number of College of Engineering courses in which innovative educators are transforming the classroom into a center for active learning. Also underway are more formal initiatives, such as the University-wide Redesigning the Undergraduate Learning Experience (RULE) program, that are replacing the traditional lecture hall in courses such as EK301: Engineering Mechanics I with a learning studio where students collaborate at round tables to solve problems under the guidance of faculty and graduate teaching fellows.

“One of the greatest benefit of ‘flipping’ and other active learning approaches is the rapid feedback that students receive at a time when the ideas are still fresh in their mind,” noted Professor Donald Wroblewski (ME), Associate Dean for Educational Initiatives, who began flipping the aerospace senior design course in 2009. “Students leave class with a level of clarity and a sense of accomplishment that are hard to achieve in traditional lecture formats.”

After one round of the “Navier-Stokes Speed Dating Game,” the most popular date describes the underlying physics behind his solution on the communal whiteboard. Soon another student joins him at the board, challenging his interpretation, and in no time more than half the class weighs in from their workstations. The room is abuzz with the kind of spontaneous intellectual exchange that would appear out of place during a traditional lecture. Though Barba guides the discussion, the class practically runs itself, decisively turning the old paradigm on its head.


More information about the flipped CFD classroom is available here.

By Mark Dwortzan