The current concerns over global warming and its consequential effects have brought back into consideration schemes that exploit wind power for maritime propulsion. Of these, the most promising is arguably the Flettner rotor which 85 years ago enabled the Baden-Baden to make such a spectacular record crossing of the Atlantic to be feted on docking in New York.

The present seminar reviews the historical development and current commercial initiatives as a preliminary to considering the CFD modelling of the flow around the Flettner rotor. The enquiry, by the Turbulence Mechanics  group at Manchester University, also includes the proposal, originally tested and advocated by Thom, of adding discs to the Flettner rotor to intensify the Magnus force. Comparisons, employing an unsteady RANS approach, are made at lower spin rates and far lower Reynolds numbers with available DNS and LES studies as well as with experimental data at Reynolds numbers and spin rates more representative of those at which Flettner-propelled vessels would operate. Generally good agreement with the various data sources has emerged, including the fact, first reported rather incredulously by Thom, that with discs present, at moderately high spin rates negative drag coefficients may occur. Further steps to be taken in the future are briefly discussed.

Professor Brian Launder read Mechanical Engineering at Imperial College, London and carried out doctoral research in Fluid Mechanics at MIT, obtaining his doctorate for experimental studies of laminarization in 1965 before returning to a lectureship at Imperial. Thereafter he was promoted to Reader in Fluid Mechanics in 1971 for his early research on Turbulence Modelling. In 1976 he moved to the University of California, Davis as a full professor where he stayed for nearly four years before returning to the UK to head the Mechanical Engineering Department’s Thermo-Fluids Division at UMIST in Manchester. He led the Division for more than fifteen years and served two terms as Head of Department.

In 1998 he became the first chairman of UMIST’s Environmental Strategy Group. Outgrowths of that role were his appointment to the regional directorship of the Tyndall Centre for Climate Change Research from 2000-2006 and his securing funding to create the Mason Centre for Environmental Flows. These appointments led to his deepening involvement in the problems of climate change and, in particular, the strategies that may be taken should mankind fail (as seems increasingly likely) to keep carbon dioxide levels within safe limits. Arising from these concerns he edited the book Geo-engineering Climate Change: Environmental necessity or Pandora’s box? (CUP, 2010) and served on the Royal Society’s committee of enquiry into geoengineering. His principal research interest has however been developing models of turbulence to explain complex engineering phenomena within the framework of RANS-based CFD. His efforts in this area have been brought together in a textbook that Cambridge University Press have recently published, written with his first PhD student, Kemo Hanjalić: Modelling Turbulence in Engineering and the Environment: Second-moment Routes to Closure (CUP, 2011). Complementary to that interest, he recently completed Osborne Reynolds: A Turbulent Life that appeared as the opening chapter in the popular volume A Voyage through Turbulence (CUP, 2011).

Professor Launder was elected a Fellow of both the Royal Society and the Royal Academy of Engineering in 1994 for his contributions to the modelling, measurement and computation of turbulent flows. Other awards have included an honorary professorship from Nanjing Aeronautical Institute, honorary doctorates from the INP, Toulouse and the Université Paul Cézanne, Aix-en-Provence, France and the University of Thessaloniki, in Greece. In 2004 he was awarded the James Clayton Prize of the IMechE for his lifetime research achievements. Since 1987 he has served as editor-in-chief of the International Journal of Heat & Fluid Flow, a position he relinquished to enable him to make his present round-the-world trip.