Nonlinear, Nonlocal and Fractional Turbulence

Introduction.- Reynolds Averaging of the Navier-Stokes Equations (RANS).- The closure problem.- Boussinesq's 'constitutive law'.- First turbulence models for shear flows.- Review of nonlinear and nonlocal models.- The Difference-Quotient Turbulence Model (DQTM).- Self-similar RANS.- Elementary turbulent shear flow solutions.- Thermodynamics of turbulence.- Turbulence - a cooperative phenomenon.- Conclusions and outlook.

Peter W. Egolf made an apprenticeship as a heating designer and studied at the University of Applied Sciences of Central Switzerland heating and air conditioning. After working in an industrial R&D laboratory, he studied physics at the Swiss Federal Institute of Technology (ETH Zurich). In 1984 he obtained his diploma in Dynamical Meteorology. Then he entered a R&D division at Gebrüder Sulzer AG in Winterthur, where he invented and investigated industrial air conditioning systems. At an advanced age he had the opportunity to make a PhD in a Noble Laureate 'family' in low-temperature physics (superfluidity). In 1989 Egolf introduced the Lagrange-Hamilton description of the free surface of quantum fluid He II. In 1990 he obtained his PhD at ETHZ with an innovation award. In the late 1980's he invented the Difference-Quotient Turbulence Model (DQTM). From 1990 on a ten years' employment at the Swiss Federal Institute for Materials Testing and Research followed in the field ofenergy and buildings. In 1994 he entered the field of research on ice slurries. In 1998 Egolf created the International Working Party on Ice Slurries of the International Institute of Refrigeration (IIR) and was its first President. From 2000-2018 he was the head of the Theory and Numerics Division (SIT) of the Thermal Sciences Institute at the University of Applied Sciences of Western Switzerland. He initiated a second International Working Party of the IIR (on Magnetic Refrigeration), and for ten years he was serving as its President. Furthermore, he was awarded the first prices of the Swiss Technology Awards 1996 and 2006. Today, Peter W. Egolf is retired, however, he is still involved in the study of fundamental research on fractional turbulence and nonextensive thermodynamics of turbulence. He was a main organizer of eight international conferences. Egolf invented or co-invented a new melting/freezing model, an innovative storage device for ice slurries, a translucent solar