Inge L. Ryhming – författare

The aim of the 1989 GAMM Workshop on 3D-Computation of Incompressible Internal Flows was the simulation of a realistic incompressible flow field in an important industrial application. In view of the difficulties involved in formulating such a test case, requiring the availability of an experimental data base, extreme care had to be taken in the selection of the proper one. Professor I. L. Ryhming''s proposal, that the flow through a Francis turbine configuration or parts thereof would be feasible as a test case, because of the numerical challenges as well as the possibility to produce an experimental data base by using the experimental facilities of the Hydraulic Machines and Fluid Mechanics Institute (IMHEF) at the Swiss Federal Institute of Technology in Lausanne (EPFL), was accepted by the GAMM Committee in April 1987. A scientific committee, formed under the chairmanship of Professor I. L. Ryhming, met a few times to decide on the Francis turbine configuration, the test case specifications, etc. , whereby the design input came from the water turbine experts. This committee decided to restrict the studies to the three following typical applications for the best operating point of the turbine: • simulation of the 3D flow in a Francis runner in rotation • simulation of the 3D flow in the distributor (stay and guide vane rings) of this turbine • simulation of the 3D flow in an elbow draft tube The simultaneous computation of two or three of these geometries was encouraged.

The IMACS-COST conference on "Computational Fluid Dynamics, Three-Dimensional Complex Flows" was held in Lausanne, Switzerland, September 13 - 15, 1995. The scien­ tific sponsors of the conference were • IMACS: International Association for Mathematics and Computers in Simulation, • COST: European Cooperation in the field of Scientific and Technical Research, • ERCOFTAC: European Research Community on Flow, Turbulence and Combus­ tion. The scientific interests of the IMACS and ERCOFTAC associations are closely related to computational fluid dynamics whereas the European Union programme COST covers a wider range of scientific subjects. The COST'' Action F1'' launched in 1992 by Professor I. L. Ryhming deals with "Complex three-dimensional viscous flows: prediction, modelling, manipulation and control". It has several subtopics among which numerical methods and modelling issues are the main areas of research and development. The meeting gathered together eighty-seven scientists, engineers and researchers from sev­ enteen countries: Belgium, Finland, France, Germany, Greece, Hong Kong, Israel, Italy, Japan, the Netherlands, Norway, Russia, Spain, Sweden, Switzerland, United Kingdom, United States of America. All major numerical approximation methods were discussed: finite differences, finite volumes, finite elements, spectral methods. The topics covered by the sixty communications spanned the full spectrum of computational fluid dynam­ ics: direct numerical simulation, large-eddy simulation, turbulence modelling, free surface flows, non Newtonian fluids, thermal convection, etc.

The IMACS-COST conference on "Computational Fluid Dynamics, Three-Dimensional Complex Flows" was held in Lausanne, Switzerland, September 13 - 15, 1995. The scien­ tific sponsors of the conference were • IMACS: International Association for Mathematics and Computers in Simulation, • COST: European Cooperation in the field of Scientific and Technical Research, • ERCOFTAC: European Research Community on Flow, Turbulence and Combus­ tion. The scientific interests of the IMACS and ERCOFTAC associations are closely related to computational fluid dynamics whereas the European Union programme COST covers a wider range of scientific subjects. The COST' Action F1' launched in 1992 by Professor I. L. Ryhming deals with "Complex three-dimensional viscous flows: prediction, modelling, manipulation and control". It has several subtopics among which numerical methods and modelling issues are the main areas of research and development. The meeting gathered together eighty-seven scientists, engineers and researchers from sev­ enteen countries: Belgium, Finland, France, Germany, Greece, Hong Kong, Israel, Italy, Japan, the Netherlands, Norway, Russia, Spain, Sweden, Switzerland, United Kingdom, United States of America. All major numerical approximation methods were discussed: finite differences, finite volumes, finite elements, spectral methods. The topics covered by the sixty communications spanned the full spectrum of computational fluid dynam­ ics: direct numerical simulation, large-eddy simulation, turbulence modelling, free surface flows, non Newtonian fluids, thermal convection, etc.

This volume contains the 22 contributions of the Workshop on 3D-Computation at Incompressible Internal Flows held in 1989 at the EPFL, Lausanne, Switzerland. This was the first GAMM Workshop on Numerical Methods in Fluid Mechanics developed to a real industrial problem, namely the flow simulation through a Francis turbine configuration. A large part of this book deals with the analysis of the contributed simulations and with their comparisons with the experimental data. It also contains a detailed description of the text cases, of the experimental set up and of the experimental data base.