Seminar "Characterisation and modelling of wall turbulence with strong heat transfer" by Prof. Rene Pecnik
Prof. Rene Pecnik
Process and Energy Department
Delft University of Technology
Turbulent flows with strong heat transfer are common in nature and engineering applications. In general, heat transfer is accompanied with strong temperature gra- dients and consequently gradients in thermophysical properties. How these gradients affect turbulence has been subject to research for several decades. This talk will out- line a novel approach to characterize wall turbulence affected by heat transfer using conservation equations that have been scaled by semi-local quantities. Using direct numerical simulations of heated flows in a channel we show that the semi-locally scaled stress balance equation can be used to derive a universal velocity transforma- tion that is capable of collapsing velocity profiles from variable property flows with incompressible law of the walls. Moreover, if the turbulent kinetic energy equation is derived by semi-locally scaled momentum equations we show how models for LES or RANS can be corrected to yield accurate results.
In 2007 Rene Pecnik received his doctorate with distinction from Graz University of Technology, Austria. From 2007 to 2010 he was post- doctoral researcher at the Center for Turbulence Research at Stanford University, United States. In 2010 he joined Delft University of Technol- ogy as an Assistant Professor and since 2016 he is Associate Professor.