Mikhail Aleksandrovich Isakovich

Mikhail Aleksandrovich Isakovich
(1911-1982)

 

Mikhail Aleksandrovich Isakovich was born on May 28, 1911, in Odessa.

In 1928, Isakovich became a student of the Shipbuilding faculty of the Odessa Polytechnical Institute that was later transformed into the Institute of Water Transportation Engineers. Isakovich graduated from this institute in 1932.

In 1934, he became a post-graduate student at the Moscow State University. In 1938, he received a candidate degree for his studies of viscoelasticity.

From the very beginning of his scientific career, Isakovich was under the influence of the most prominent physicist L.M. Mandelshtam - the leader of a large scientific school to which Isakovich also belonged. After completing his post-graduate course, Isakovich taught theoretical mechanics at the Pedagogical institutes in Moscow and Orel.

During World War II, Isakovich was sent to an aviation school where he gave lectures on the theory of flight. These lectures formed the basis of his book published in 1947 under the title "Theory of Flight".

In 1946, Isakovich started working at the Acoustical laboratory of the Lebedev Physical Institute of the Academy of Sciences of the USSR.

In 1953, he received the degree of doctor of science.

In 1954, the Acoustical laboratory was transformed into the Acoustics Institute, and Isakovich became a deputy head of the Theoretical department of this institute. In 1962, he became head of this department and occupied this position till the end of his life.

The scope of scientific interests of Isakovich was fairly wide. He worked in different fields of acoustics: sound propagation in fluid and microinhomogeneous media, sound scattering at random inhomogeneities, nonlinear acoustics, vibrations of curved rods, sound radiation, and sound insulation - these are the subjects of his numerous scientific papers.

The early studies performed by Isakovich were concerned with viscoelasticity.

After 1945, he began investigating sound propagation in microinhomogeneous media, and these problems continued to attract his interest many years later.

In 1948, he published his two first papers on this subject - "On the Theory of Sound Absorption in Polycrystals" and "On Sound Propagation in Emulsions". The contents of these papers were subsequently included in many lecture courses on general and theoretical physics.

These publications were followed by the paper on "Wave Propagation in Highly Viscous Liquids" (1966) where Isakovich proposed a new approach to describing highly viscous (easily supercooled) liquids. According to Isakovich, such a liquid can be represented by a microinhomogeneous medium in the form of an unordered phase containing ordered regions that are able to rearrange themselves to a more or less ordered state under pressure (stress) variations in a wave. This publication aroused much interest, and, even to-day, it attracts the attention of many physicists.

Another series of studies performed by Isakovich was related to wave scattering at rough and inhomogeneous surfaces. His publication on "Wave Scattering from a Statistically Rough Surface" (1952) resulted in the replacement of the geometrical ray approach by a more precise diffraction approach in combination with the rigorous inclusion of the statistical characteristics of roughness.

Among acoustical engineers, Isakovich is known as the author of the system for sound and vibration damping constructed on the basis of similarly tuned resonators installed close to each other in waveguides or on vibrating plates, rods, or other structures. Dampers designed on the basis of such a system and called by Isakovich "waveguide" dampers proved to be highly efficient. The studies of sound scattering from inhomogeneities in waveguides served as a basis for another method of sound insulation proposed by Isakovich - the method based on forming a periodic roughness on the waveguide walls.

In late 1960s, Isakovich began the studies of vibrations and waves in rods of complex structure. These studies were initiated because of the need for the development of new instruments for ultrasonic surgery.

Isakovich was also deeply involved in tutorial activities. He wrote several chapters for the well-known "Text-Book on Elementary Physics" edited by G.L. Landsberg. For years, he delivered lectures on general acoustics at the Moscow Physico-Technical Institute. These lectures were included in his book published in 1973 under the title "General Acoustics".

More than ten post-graduate students became candidates of science under his supervision.