Preface. Images of Leen van Wijngaarden; P.J. Zandbergen. A Brief Summary of L. van Wijngaarden's Work Up Till his Retirement; A. Prosperetti. 3. Cavitation Research and Ship Propeller Design; G. Kuiper. 4. On the Shape and Dimensions of Three Dimensional Cavities in Supercavitating Flows; M.P. Tulin. 5. The Peculiar Dynamics of Cavitation Bubbles; W. Lauterborn, C.-D. Ohl. 6. The Art, Craft and Science of Modelling Jet Impact in a Collapsing Cavitation Bubble; J.R. Blake, et al. 7. Sheet Cavitation and Cloud Cavitation, U-Entrant Jets and Three-Dimensionality; D.F. De Lange, G.J. De Bruin. 8. The Iordansky-Kogarko-van Wijngaarden Model: Shock and Rarefaction Wave Interactions in Bubbly Media; V.K. Kedrinskii. 9. MHD Turbulence at the Laboratory Scale: Established Ideas and New Challenges; R. Moreau. 10. Selforganization of Quasi 2-D Flows in a Rectangular Container; G.J.F. van Heijst, H.J.H. Clerckx. 11. The Fascination of Vortex Rings; N. Riley. 12. Ocean Spray Modelling for Tropical Cyclone Wind Speeds; J. Lighthill. 13. Unsteady Liquid Jets; G.E.A. Meier, et al. 14. Biharmonic Problem in a Rectangle; V.V. Meleshko. 15. Nonlinear Waves and the Origin of Bubbles in Fluidized Beds; G.M. Homsy. 16. Instability of Sedimenting Bidisperse Particle Gas Suspensions; P. Valiveti, D.L. Koch. 17. On the Direct and Radiated Components of the Collisional Particle Pressure in Liquid-Solid Flows; R. Zenit, et al. 18. The Fokker-Planck Equation for Bubbly Flows and the Motion of Gas Bubble Pairs; J.B.W. Kok. 19. Properties and Averaged Equations for Flows of Bubbly Liquids; P.D.M. Spelt, A.S. Sangani. 20. Shape Oscillations of Rising Bubbles; K. Lunde, R.J. Perkins. 21. Bouncing and Coalescence of Bubble Pairs Rising at High Reynolds Numbers in Pure Water and Aqueous Surfactant Solutions; P.C. Duineveld. 22. Some Aspects of the Lift Force on a Spherical Bubble; J. Magnaudet, D. Legendre. 23. Dispersion of Gas Bubbles in Large-Scale Homogeneous Isotropic Turbulence; P.D.M. Spelt, A. Biesheuvel. 24. Qualitative Questions in Fluid Mechanics; J.C.R. Hunt.