R. Cengiz Ertekin

After almost 30 years, he retired from the University of Hawaii in September 2015. Starting in March 2014, he became a Guest Professor at the College of Shipbuilding Engineering of Harbin Engineering University in China.

Some of the recent tsunami and hurricanes, such as Tohoku tsunami in Japan (2011) and Hurricane Katrina in the United States (2005), caused significant damage to the decks of coastal bridges and structures. Interaction of surface waves with coastal bridges is a complex problem, involving fluid-structure interaction, multi-phase fluids, wave breaking, and overtopping. These are of course in addition to the difficulties associated to the structural analysis. Ertekin and his students studied bridge failure mechanisms and possible mitigating solutions. They developed models used to assess the vulnerability of coastal bridges in USA to tsunami and storm surge and waves.

Starting 1990's, Ertekin pioneered the research on hydroelasticity of VLFS. He and H. Ronald Riggs of the Civil Engineering Department at the University of Hawaii coined the term VLFS. They have solved the hydroelasticity problem of VLFS by use of both linear and nonlinear approaches, in two and three dimensions. Ertekin has also introduced new approaches and equations to study this topic, including the use of nonlinear water wave models to analyse the hydroelastic response of VLFS of mat type (see e.g., and ).

He has been on the editorial board of more than ten internationally leading journals since early 1990s (see e.g., and ), and editor of several special issues in various journals, see e.g. Renewable Energy: Leveraging Ocean and Waterways special issue of Applied Ocean Research journal (2009). He was the Co-Editor-in-Chief of Elsevier's Ocean Engineering journal (2006-2010), and he is the Founding Editor-in-Chief of Springer's Journal of Ocean Engineering and Marine Energy. Ertekin has been keynote speaker of several leading meetings and conferences, see e.g. and.

In 1985, Ertekin joined the Research Center of Shell Development Company in Houston, Texas. He took a faculty position (hired at the Associate Professor level) at the Department of Ocean Engineering of the University of Hawaii at Manoa (UH) in 1986, and received tenure within four years and was promoted to Professor in 1994. The Ocean Engineering Department of UH was established by Prof. Charles Bretschneider in 1966 and is one of the first of its kind in USA.

R. Cengiz Ertekin was born and raised in Turkey. He received a B.Sc. degree in Naval Architecture and Marine Engineering from Istanbul Technical University, the top technical university of Turkey, in 1977. Following the encouragement of his advisor, Prof. M Cengiz Dokmeci, he moved to the Department of Naval Architecture and Offshore Engineering of the University of California at Berkeley, United States, for higher education. He received his M.Sc. and Ph.D. degrees in 1980 and 1984, respectively. His M.Sc. advisors were Professors Marshall P. Tulin and William C. Webster. His Ph.D. advisor was Professor John V. Wehausen. Cengiz was the last student of Prof. John V. Wehausen before his retirement. After graduation, Prof. Wehausen offered Cengiz a Postdoctoral Research Assistant position for 18-months at U.C. Berkeley.

The Green-Naghdi (GN) equations are nonlinear water wave equations that were originally developed by British mathematician Albert E. Green and Iranian-American mechanical engineer Paul M. Naghdi in the 1970s (see,). The original equations, namely the Level I GN equations, are mostly applicable to the propagation of long waves in shallow waters. However, high level GN equations are also developed which are applicable to deep water waves. The equations differ from the classical water wave theories (e.g. Boussinesq equations) in that the flow need not be irrotational, and that no perturbation is used in deriving the equations. Hence, the GN equations satisfy the nonlinear boundary conditions exactly, and postulate the integrated conservation laws. Although the GN equations were developed very recently (compared to other wave theories), they are well-known and fairly understood by the research and scientific community.