Master of Turbulent Forces: How Academician Yershin Brought Kazakhstan’s Hydromechanics to International Prominence

Abstract

Some scientists’ names remain only on the yellowed pages of dissertations. Others are builders capable of harnessing the intricate laws of physics to meet the needs of a vast country and making the world—from Moscow to Washington, the centres of the two most powerful opposing military superpowers—listen to the voice of Kazakhstan’s science. Academician of the National Academy of Sciences of the Republic of Kazakhstan, Doctor of Technical Sciences, Professor Shakhbaz Alimgireyevich Yershin (5 September 1926–2 August 2019) was one such person.

This year, a grateful scientific community commemorates the centenary of a man who established a distinctive national school of hydroaeromechanics, peered into the heart of raging flames, and put the Navier–Stokes equations to work for industry.

Drawing on the monograph Paradoxes of Aerohydrodynamics and publications by members of Yershin’s scientific school, this review discusses flows of viscous and viscoplastic media in channels, the effects of dissipative heating on viscosity and flow resistance, and the hydrodynamic conditions contributing to localised damage in oilfield pipelines. It examines transport through permeable walls, gas distribution in catalytic apparatuses, the development of free jets, and the evolution of vortical structures. Particular attention is paid to the effects of temperature on the structure of gas jets and the interplay between mixing, ignition, and fuel burnout during supersonic combustion. The review shows that apparent contradictions between conventional understanding and actual flow behaviour can be explained by accounting for interconnected physical processes and the limits of applicability of computational models. It emphasises the importance of comparing theory with experiment, distinguishing qualitative explanations from quantitative validation, and the role of a scientific school in cultivating a research culture. The review highlights the practical significance of Yershin’s legacy for the energy sector, the oil industry, and the improvement of technological apparatuses.