Dr. Spyrou gives Weinblum lecture at Carderock

The 39th Weinblum Memorial Lecture was given by Dr. Kostas Spyrou at Naval Surface Warfare Center, Carderock Division in West Bethesda, Maryland, on Nov. 13. Spyrou is a professor at the School of Naval Architecture and Marine Engineering for the National Technical University of Athens in Greece.

Dr. Kostas Spyrou, a professor at the School of Naval Architecture and Marine Engineering for the National Technical University of Athens, Greece, gives a lecture Nov. 13, 2017, at Naval Surface Warfare Center, Carderock Division, as part of the Weinblum Memorial Lecture series, named for Georg Weinblum. (U.S. Navy photo by Monica McCoy/Released)

This lecture series was established in 1978 by colleagues of Georg Weinblum, a German engineer who studied ship hydrodynamics and had major contributions to aspects such as waveresistance theory, maneuvering, ship motions and hydrofoils. Weinblum also worked at Carderock from 1948-1952, then known as the David Taylor Model Basin. The lecture series honors a person each year who exemplifies the ideals of Weinblum.

Spyrou’s lecture, “Homoclinic Phenomena in Ship Motions,” was given first in Hamburg, Germany, about a year ago and then at Carderock, which is normal for the lectures.

“The title homoclinic is strange for most people, but it is not strange to me as it is a Greek word and I’m a Greek person, so I understand the deeper meaning of the word,” Spyrou said, describing homoclinic as one special class of non-linear phenomena that can affect ship systems that are dynamic, such as a giant wave that would be very rare.

Spyrou has been working with Dr. Vadim Belenky, a naval architect with Carderock’s Simulations and Analysis Branch (Code 851), over the past nine years in a collaborative effort to study these rare events and looking into extreme values, into the extremes in ship motion, such as capsizing.

Specifically, the objective of Spyrou’s lecture was to identify the cases of strange behavior that might happen to a ship and may affect the safety of the system in a critical mode as something that happens very suddenly. Once identified, Spyrou said it’s possible to approach the problem with rational scientific approach and engineers or Sailors may be able to predict the phenomena, and therefore see ways to avoid the phenomena.

“I have tried to identify all the cases we know about such phenomenon, which are relevant to ship motions, from the studies that have taken place in the past,” Spyrou said. “It’s not the kind of work that many people are actually doing right now because it’s about something that’s very rare. You don’t expect a ship to capsize in its lifetime, but you know that this is something you need to avoid at any cost.”

Spyrou said it is essential to put some effort in this area of study. With more knowledge, there may be a way to prevent a disaster with simple design changes. But there may be operational strategies, as well, by avoiding getting the ship into trouble in the first place.

“One of the conclusions was that we need to do more to educate naval architects to understand the phenomenon,” Spyrou said, adding that the math used to describe homoclinic phenomena needs to be included in the naval architect curriculum.

By Kelley Stirling, NSWCCD Public Affairs