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and normal responses, with the square of Poisson’s ratio, γ2, as the small parameter. Somewhat sur- prisingly, Rudolph found that well below the shell’s ring frequency, with a radial drive the zero’th order ratio of normal-to-surface motions is one of local reaction. It is not until the theory is carried out to O(γ2) that “wave propagation from axial compression begins to assert itself”. After his formal presenta- tion but quite applicable to his talk, Rudolph shared a wonderfully
amusing anecdote that typified Miguel’s humor, often self-dep- recating. Apparently Miguel was able to argue, albeit without much success, that his appearance of weight gain was merely a consequence of Poisson coupling owing to his becoming short- er with age.
Ann Stokes, in her paper “Sound radiation by parallel coated plates separated by a fluid layer: here and then”, fond- ly recalled Miguel’s extraordinary facility to reduce this com- plex configuration, and in turn complex set of equations , to a manageable asymptotic mathematical model that was read- ily solved, while retaining the fundamental physics. In this particular case, with the primary interest being the far field (on-axis) radiated pressure from driven submerged vehicles, a lumped parameter model for the various individual layers generated valuable insights into the resonance enhancements predicted by the full analytical model. And, as described by Ann, such insights continue to be beneficial, when similar models are developed for evaluating noise control strategies for underwater pile driving activities. More generally, this modeling proficiency became one of Miguel’s trademarks, and led to many of the canonical problems in structural- acoustics with which he is identified.
Klaus Kleinschmidt talked about an often overlooked aspect of Miguel’s career, his work on acoustical products development, in his paper “Cooperating with Miguel on improvements of the acoustical product SOUNDBLOX”. SOUNDBLOX is a slotted concrete block, designed to behave as a Helmholtz resonator, enhancing acoustic absorption in the vicinity of the cavity natural frequency. The cavity may be filled with absorptive material and a broader absorption spectrum was obtained with multiple cavities. As Klaus noted, the fact that the product, first introduced in the 1950’s is still on the market, reflects well on their collaboration.
Miguel Junger was born in Dresden, Germany on 23 January 1923. His father was a journalist for the French and German press, and his family lived in Germany, Spain and France, where he received his high school education at the French Lycee. Miguel Arrived in the USA with his parents in 1941. He entered the Masssachusetts Insittute of Technology, earning the B.S. degree in 1944 and the M.S. degree two years later. He subsequently went to Barry Controls where he was mentored by C.E. Crede. His work with Crede on the shock resistance of shipboard mechanical equipment was published in book form by the Navy Bureau of Ships. Here, it is inter-
esting to note that it was conversations with Crede that led Miguel to pursue his doctoral studies, and Miguel was hon- ored by the ASA in 1987 with the Trent-Crede Medal, one of the men for whom the medal is named.
Miguel received his Sc.D. from Harvard University in 1951 as a Gordon McKay Fellow and worked under F.V. Hunt at the Harvard University Acoustics Research Laboratory. It was here that Miguel met fellow student Preston Smith, Jr. In 1955 Miguel and Preston became founding partners of Cambridge Acoustical Associates, Inc. a small consulting firm in Cambridge, MA. While Preston left CAA and joined Bolt, Beranek and Newman in 1959, Miguel worked at CAA as President, and as Chief Scientist until his retirement in 1997.
Miguel’s extraordinarily productive career has resulted in almost one hundred technical papers, many in the JASA, chap- ters in books of collected works, and two published books, one in French, the other in English. The first book, coauthored with M. Perulli and entitled “Elements d’Acoustique Physique”, grew out of a collaboration while Miguel lectured at the Universite’ de Technologie de Compiegne. The second, “Sound, Structures and their Interaction”, coauthored with David Feit, first published in 1972, and reissued as a second edition in 1986 and then reprint- ed by the ASA in 1993. It is widely acclaimed and international- ly recognized as one of the classic structural-acoustic texts.
In both style and content, and without exception, Miguel’s writings read as celebrations of discovery and understanding, and are joys to behold.
Complementing his scholarly contributions, Miguel has played an equally important teaching role as lecturer and mentor. In addition to his stint at the Universite’ de Technologie de Compiegne, he has lectured at MIT and Pennsylvania State University. Additionally, the work of his associates at CAA and “graduates” of the firm who have pro- gressed elsewhere, including those who join us in this tribute today, provide a continuing testimony to his role as educator.
Miguel has been honored by his peers throughout his career. For examples, he has been elected to fellowship in both the Acoustical Society of America and the American Society of Mechanical Engineers, chosen to present a distinguished Lecture at Noise-Con 87, and selected to receive the Per Bruel Gold Medal by ASME, and, as mentioned above, earned the ASA’s
Trent-Crede Medal in 1986. In closing, both for his sci- entific brilliance and per- sonal warmth and integrity, Miguel C. Junger, “the father of structural acoustic”, will be profoundly missed.
Portions of this article were excerpted from the Citation to Miguel C, Junger in con- nection with his being awarded the Trent-Crede Medal by the ASA.
Miguel Junger and son Sebastian
36 Acoustics Today, October 2013