Professor Algirdas Žukauskas was for a long time very dear friend of the Laboratory for Thermal Engineering and Energy of the VINCA Institute of Nuclear Sciences. Probably in the middle of sixties, he was for the first time guest of our Laboratory. Many of us have honour and pleasure to met him in Yugoslavia, at our homes, in Vilnius or Kaunas, or in many places in Soviet Union, in Moscow, Novosibirsk or in Minsk, at conferences or in relaxed friendly meetings in the evenings. Professor Algirdas Žukauskas was a frankly and great friend of Yugoslavia. He supported opening of scientific cooperation with our Laboratory and other scientific organizations in Yugoslavia. Many of our researchers passed long or short specialization in the Institute of Physical-Technical Problems of Energetic, of the Lithuanian Academy of Sciences. Influence of his scientific approach and results, in the field of cross flow around single cylinders or bundle of tubes, on the research program in this field in Laboratory for Thermal Engineering and Energy can not be overestimated. His contribution to the organization of the International Center for Heat and Mass Transfer, organized and working in Yugoslavia from 1968 to 1992, was extremely recognized. As a small contribution to the memory of Professor Algirdas Žukauskas, and to express our feelings of appreciation for his friendship and contribution to the development of heat and mass transfer science in Yugoslavia, and particularly in Laboratory for Thermal Engineering and Energy of the VINČA Institute of Nuclear Sciences, we decided to reprint a contribution published in his memory in the journal ENERGETIKA, 1998, Nr. 2. published by the Lithuanian Academy of Sciences.
Belgrade, Vinča, Yugoslavia, April 22, 1999.