TURBULENT FLOWS UNDERGOING DISTORTION AND ROTATION - A REPORT ON EUROMECH-288

The 288th EUROMECH Colloquium, on the effects of distortion and rotati on on turbulent motion, was held in Ecully (Ecole Centrale de Lyon) fr om 6-8 April 1992 with the author acting as chairman. There were fifty -five participants with widely different backgrounds. A close mutual i nteraction did occur between scientists interested in 'Rapid Distortio n Theory' (RDT) or linear stability analysis, non-linear stability ana lysis, Direct (or Large Eddy) Numerical Simulation (DNS), and one- and two-point statistical approaches. Qualitative comparisons with recent experimental results were also made. Approaches in geophyiscal turbul ence were compared to those used in engineering, in order to clearly d isplay similarities and differences in conclusions despite their diffe rent terminology and 'jargon'. In addition to qualitative results on t he stability and turbulence, threshold values were proposed for dimens ionless numbers, close to specific Rossby numbers. Several talks illus trated how the statistical approach reflected the emergence of oriente d structures. New proposals for improving one- and two-point closure m odels for rotational mean flows were introduced. Twenty-seven papers w ere presented, covering these different topics. These papers are summa rized in this report with the purpose of giving an up-to-date view of current research in rotating fluids with distortion.