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MIT Sea Grant Fluid Dynamics Expert Dixia Fan (PhD ’19) Wins De Florez Award

The Robotic Intelligent Towing Tank for Self-Learning Complex Fluid-Structure Dynamics

After six years of working with MIT Sea Grant Director Professor Michael Triantafyllou–culminating in a novel intelligent towing tank design – Dixia Fan recently completed and defended his Mechanical Engineering dissertation at MIT. Now, Dr. Fan has won the de Florez Award Competition in a four-way tie in the Graduate Science Category, demonstrating “Outstanding Ingenuity and Creative Judgment”.

Dr. Fan set out to overcome what he calls the “curse of dimensionality” inherent in hydrodynamics research. An experiment with eight parameters affecting performance, from pressure to flow velocity, would result in 100 million experimental runs. Reasoning that it would take a single PhD student up to six years to perform 3,000 experiments of this scale, he decided to create a “smarter way of doing this.”

Working between the MIT Towing Tank in the Center for Ocean Engineering and the MIT Sea Grant facility, Dr. Fan created a robotic intelligent towing tank system that could perform, analyze, and design experiments automatically through applications in artificial intelligence and deep learning. In six months,the smart tank completed nearly 100,000 experiments. “If we performed traditional techniques on the problem we studied,” Dr. Fan explains, “it would take 950 years to finish the experiment.”A key shift in both the physics observation and machine learning methods was moving away from a white box or black box approach, in which the researcher knows every intermediate step, or none at all,between the inputs and outputs. With the physical-informed self-learning system, Dr. Fan applied a grey box approach, leveraging both the physical law (as constraints) and data-driven machine learning techniques. He designed the intelligent towing tank to take partial control over the parameters of each experiment, automatically adapting to achieve a range of objectives, from understanding physical phenomena to reducing drag and increasing lift.

Dr. Fan and Prof. Triantafyllou involve undergraduates and international researchers in the work. Over MIT’s Independent Activities Period, first year Logan Vawter joined the research to investigate vortices, a classic problem linked to towing cylinders in the water. Vortices shed from moving cylinders can cause a multitude of real-world repercussions like offshore oil platform collapse. Vawter analyzed flow patterns and incorporated sensors to measure the pressure distribution around the cylinder.This fall semester, MIT Sea Grant will also host two visiting students from the Netherlands and China, also Dr. Fan’s country of origin. Under the supervision of Dr. Fan and Professor Michael Triantafyllou, the international collaborators will dive into smart flow adaptations and vortex-induced vibrations to extract flute energy from water currents. “We tried to suppress these vibrations,” explains Dr. Fan. “Now we try to harness them.”

Recognized for their application of creative judgement in engineering design, three other MIT students were awarded the de Florez Award in the Graduate Science Category:

Chinmay S. Kulkarni, Persistent Rigid Sets in Ocean Flows Help Predict the Environmental Impact of Deep Sea Mining Activities

Justin D. Beroz, Stability Limit of Electrical Droplets

Nickolas P. Demas, A Miniature, Broadband Acoustic Spectrometer: Design of a Unified Attenuation Model, Device Development, and Experimental Performance