Fred Stern: Revolutionizing Ship Hydrodynamics

For 17-year-old Fred Stern, the future looked bright from the deck of a sailboat racing across the waters of Lake Ontario. The young man from Syracuse, N.Y., took advantage of his home’s close proximity to the Great Lakes to spend every moment he could sailing.

With a small push from his father, Stern channeled his love for sailing into a successful career as a mechanical engineer focusing on ship hydrodynamics. Stern started with a correspondence course in yacht design, followed by BS, MS, and PhD degrees in naval architecture and marine engineering from the University of Michigan.

Revolutionary Research

Today, Stern heads up the ship hydrodynamics program at IIHR—Hydroscience& Engineering, where he is one of his field’s foremost visionaries, leading a revolution in naval ship design.

No longer must the navy “build and test” its ships — with real sailors aboard, risking their lives — to find out how vessels will perform under real-life conditions. Researchers at IIHR are using simulation-based design (SBD) — a sort of virtual reality of ship hydrodynamics, supported by model-scale experiments — to develop a safer, less expensive way to design modern high-performance naval vessels.

"This is revolutionizing engineering," the IIHR research engineer and director of ship hydrodynamics says. In an interview with the Big Ten Network, Stern explains, “Engineering will become more and more based on simulation techniques as time evolves.”

Cracking the Code

Under his leadership, researchers at IIHR have developed a groundbreaking computer code, CFDShip-Iowa, simulating air and water flow around a virtual ship. CFDShip-Iowa is the most advanced computational fluid dynamic (CFD) computer code in the world for ship hydrodynamics, allowing researchers to predict the performance of a virtual ship prototype under extreme environmental conditions.

Computer simulations at IIHR guide model-scale physical experiments conducted in a towing tank and in a state-of-the-art wave basin at the University of Iowa Research Park. The experiments help evaluate the limitations of current mathematical models and allow researchers to develop better models. With uncertainty analysis and optimization methods, researchers are able to develop the best possible design, Stern explains.

UI engineering students, in particular, benefit from this revolution in engineering. Graduate students have been the co-developers of CFDShip-Iowa since its genesis in the early 1990s.

Undergraduates also participate, Stern says. “We need to ensure that they’re highly-trained, expert users of tools such as computational fluid dynamics,” he explains.

Stern believes an understanding of CFD is a crucial part of a 21st century engineering education. “Our students need to be exposed to and use simulation technology and computer technology from the get-go,” he says.

For Stern, sharing his expertise with students, particularly undergraduates, is a passion — it’s his way of making a difference that will extend for decades into the future. “Undergraduates are a joy to teach,” Stern toldIowa Engineer magazine. “They are so enthusiastic and open to new ideas and approaches.”

SayyedMaysamMousaviraad began as one of Stern’s students and went on to be a postdoc and now assistant research scientist, says that Stern’s solid mentoring and dedication has helped shape his research and advance his career. “He keeps the standards very high, which inspires you to face the challenge and meet the expectations,” Mousaviraad explains.

The Iowa Paradigm

Stern shows no signs of slowing down. “There’s still plenty of work for us to do,” he says. Over the next decade, he hopes to build on the “monumental strength” of the current program, based on the “Iowa paradigm” of integrated computational fluid dynamics, experimental fluid dynamics, uncertainty analysis, and optimization research.

Of course, he won’t do it all alone. The Iowa program has always depended on the talents and hard work of students, both undergraduate and graduate, as well as collaborators at IIHR and around the world. His vision for the future emphasizes international collaborations and the building-block, step-by-step approach, focusing on second-generation SBD tools, supported by physical experiments in IIHR’s towing tank, flumes, and wave basin.

Stern hopes to mentor his young faculty colleagues at IIHR so they can carry on the ship hydrodynamics program that has been a strength of the institute since Lou Landweber arrived in 1954.

Like Landweber, Stern has helped build IIHR’s unique combination of resources, facilities, and people, which promises an ongoing role for the University of Iowa in the front lines of naval ship design.