Ultrahigh Reynolds (Re) and Rayleigh (Ra) number flow can be produced and s
tudied under controlled laboratory conditions using cryogenic liquid and ga
seous He. Recent results on Rayleigh-Benard convection, pipe flow and towed
grid turbulence are discussed together with some aspects of the future dev
elopment. (C) 2000 Elsevier Science B.V. All rights reserved.