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Obituary for Professor Klaus Oswatitsch
Fluid Dynamics Research North-Hoiland
13 ( 1994) 65-66
FLUID DYNAMICS RESEARCH
Obituary for Professor Klaus Oswatitsc~ Klaus Oswatitsch, professor emeritus at the Technical University of Vienna, died on August 1, 1993, at the age of 83. From 1960 to 1980 he was Professor of Fluid Mechanics at the Technical University of Vienna. From 1956 to 1973 he was also Director of the DFVLRInstitut fur Theoretische Gasdynamik at Aachen, and from 1973 to 1978 he continued to supervise his research group, which had become part of the Aerodynamische Versuchsanstalt (AVA) at G~ttingen. As a long-standing member of the Honorary Editorial Board of Fluid Dynamics Research, Professor Oswatitsch provided strong encouragement and stimulating support to this journal. Klaus Oswatitsch was born on March 10, 19 10, in Marburg, then Austria, now Slovenia. He studied mathematics and physics in Graz, Austria. Supported by a scholarship of the DFG, he was able to join Ludwig Prandtl’s research group at the ‘cKaiser-Wilhelm-Institut (now: Max-Planck-Institut) fur Stromungsforschung”. Soon Oswatitsch proved his abilities and talents with his now famous work on condensation of water vapor in the flow of humid air through Lava1 nozzles. The invention of the shock diffusor and the formulation of the entropy theorem, which relates the drag force of a body to the entropy production in the surrounding flow field, are further examples of Oswatitsch’s productivity while at Gottingen. After World War II, Oswatitsch worked for French and British institutions and then went to Stockholm, where he taught at the Kungl. Tekniska Hogskolan (KTH) from 1949 to 1956. Significant contributions originate from this period of his life. Almost simultaneously with Guderley and von K&-man, Oswatitsch formulated the transonic similarity law. Furthermore, Oswatitsch discovered a law of equivalence, which relates subsonic and supersonic flows around a slender three-dimensional body to the flows around an axisymmetric body of equal cross-sectional area distribution. The first correct proof of the hypersonic similarity law was also given by Oswatitsch. Oswatitsch devoted his later years in Aachen and Vienna mainly to the development and improvement of the so-called analytical method of characteristics. This method, which is related to the method of strained coordinates developed by C.C. Lin and others, proved to be most useful for solving a variety of hyperbolic problems including, among others, the sonic-boom problem, the detached shock wave in transonic flow, and the flow around a delta wing with transonic leading edges. Klaus Oswatitsch has influenced the development of fluid mechanics not only by his research work, but also by his books and survey articles. The first German edition of his book on gas dynamics was translated into English and Chinese. He contributed to the “Handbuch der Physik” and the “Handbook of Engineering Mechanics,” among others. He also co-edited new editions and up-dated several chapters of Prandtl’s “Fiihrer durch die Stromungslehre” (“A Guide Through Fluid Mechanics”). In recognition of his pioneering work, Oswatitsch was awarded many honors and prizes. The prestige that he enjoyed world-wide was based not only upon his scientific achievements, but was also due to his strong personality; he yielded neither to the plights of a world war nor to the temptations of our present society of prosperity. Impressed by his high standards and his confidence in young colleagues, numerous students were permanently influenced by Oswatitsch’s personality. After accepting a student as his scientific “son” or “daughter,” his trust was unlimited and unshakable. Klaus Oswatitsch was a family man. Married to his wife, Hedwig, for 53 years, he had four The Japan Society of Fluid Mechanics.
children, Ruthild, Gerhild, Martin and Irmgard, and he had happily welcomed the birth of two grandchildren. He also had many non-scientific interests and hobbies. including various sports and high-level games of chess. Yet his life-long passion was science. Never would it have occurred to him to rest on his laurels. He worked on various research problems. including condensation of binary mixtures and turbulence, until a few months before his death. Quite naturally he was not satisfied with his pace, but he still enjoyed the excitement of making progress in the understanding of a scientific problem. It is often said that no man is irreplaceable, but it seems impossible to agree with such conventional wisdom after Klaus Oswatitsch has passed away. In his life, he has given much more than he has taken. He provided help and he passed on his scientific ideas to colleagues and students with enormous generosity. His appreciation and support for others’ achievements was a unique source of encouragement to all of us - former students and colleagues alike. We shall hold him in grateful remembrance.
Wilhelm Schneider Vienna
13 ( 1994) 65-66
FLUID DYNAMICS RESEARCH
Obituary for Professor Klaus Oswatitsc~ Klaus Oswatitsch, professor emeritus at the Technical University of Vienna, died on August 1, 1993, at the age of 83. From 1960 to 1980 he was Professor of Fluid Mechanics at the Technical University of Vienna. From 1956 to 1973 he was also Director of the DFVLRInstitut fur Theoretische Gasdynamik at Aachen, and from 1973 to 1978 he continued to supervise his research group, which had become part of the Aerodynamische Versuchsanstalt (AVA) at G~ttingen. As a long-standing member of the Honorary Editorial Board of Fluid Dynamics Research, Professor Oswatitsch provided strong encouragement and stimulating support to this journal. Klaus Oswatitsch was born on March 10, 19 10, in Marburg, then Austria, now Slovenia. He studied mathematics and physics in Graz, Austria. Supported by a scholarship of the DFG, he was able to join Ludwig Prandtl’s research group at the ‘cKaiser-Wilhelm-Institut (now: Max-Planck-Institut) fur Stromungsforschung”. Soon Oswatitsch proved his abilities and talents with his now famous work on condensation of water vapor in the flow of humid air through Lava1 nozzles. The invention of the shock diffusor and the formulation of the entropy theorem, which relates the drag force of a body to the entropy production in the surrounding flow field, are further examples of Oswatitsch’s productivity while at Gottingen. After World War II, Oswatitsch worked for French and British institutions and then went to Stockholm, where he taught at the Kungl. Tekniska Hogskolan (KTH) from 1949 to 1956. Significant contributions originate from this period of his life. Almost simultaneously with Guderley and von K&-man, Oswatitsch formulated the transonic similarity law. Furthermore, Oswatitsch discovered a law of equivalence, which relates subsonic and supersonic flows around a slender three-dimensional body to the flows around an axisymmetric body of equal cross-sectional area distribution. The first correct proof of the hypersonic similarity law was also given by Oswatitsch. Oswatitsch devoted his later years in Aachen and Vienna mainly to the development and improvement of the so-called analytical method of characteristics. This method, which is related to the method of strained coordinates developed by C.C. Lin and others, proved to be most useful for solving a variety of hyperbolic problems including, among others, the sonic-boom problem, the detached shock wave in transonic flow, and the flow around a delta wing with transonic leading edges. Klaus Oswatitsch has influenced the development of fluid mechanics not only by his research work, but also by his books and survey articles. The first German edition of his book on gas dynamics was translated into English and Chinese. He contributed to the “Handbuch der Physik” and the “Handbook of Engineering Mechanics,” among others. He also co-edited new editions and up-dated several chapters of Prandtl’s “Fiihrer durch die Stromungslehre” (“A Guide Through Fluid Mechanics”). In recognition of his pioneering work, Oswatitsch was awarded many honors and prizes. The prestige that he enjoyed world-wide was based not only upon his scientific achievements, but was also due to his strong personality; he yielded neither to the plights of a world war nor to the temptations of our present society of prosperity. Impressed by his high standards and his confidence in young colleagues, numerous students were permanently influenced by Oswatitsch’s personality. After accepting a student as his scientific “son” or “daughter,” his trust was unlimited and unshakable. Klaus Oswatitsch was a family man. Married to his wife, Hedwig, for 53 years, he had four The Japan Society of Fluid Mechanics.
children, Ruthild, Gerhild, Martin and Irmgard, and he had happily welcomed the birth of two grandchildren. He also had many non-scientific interests and hobbies. including various sports and high-level games of chess. Yet his life-long passion was science. Never would it have occurred to him to rest on his laurels. He worked on various research problems. including condensation of binary mixtures and turbulence, until a few months before his death. Quite naturally he was not satisfied with his pace, but he still enjoyed the excitement of making progress in the understanding of a scientific problem. It is often said that no man is irreplaceable, but it seems impossible to agree with such conventional wisdom after Klaus Oswatitsch has passed away. In his life, he has given much more than he has taken. He provided help and he passed on his scientific ideas to colleagues and students with enormous generosity. His appreciation and support for others’ achievements was a unique source of encouragement to all of us - former students and colleagues alike. We shall hold him in grateful remembrance.
Wilhelm Schneider Vienna