1. Fluid Dynamics Laboratory, Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
2. Energy Technology Laboratory, Department of Mechanical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
3. Commonwealth Scientific and Industrial Research Organisation, Melbourne, Victoria 3190, Australia; and Swinburne University of Technology, Department of Mechanical Engineering, Hawthorn VIC 3122, Australia