Seminar "Characterisation and modelling of wall turbulence with strong heat transfer" by Prof. Rene Pecnik

[Speaker]

Prof. Rene Pecnik

Process and Energy Department

Delft University of Technology
 

[Abstract]

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.

[Biography]

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.