Suscripción a Biblioteca: Guest
TSFP DL Home Archivos Comité Ejecutivo

RANS-SMC AND HYBRID LES/RANS MODELLING OF A BACKWARD-FACING STEP FLOW SUBJECTED TO INCREASINGLY ENHANCED WALL HEATING

Bjorn Kniesner
Fachgebiet Stromungslehre und Aerodynamik, Technische Universitat Darmstadt Petersenstr. 30, D-64287 Darmstadt, Germany

Roland Jester-Zurker
Department of Mechanical Engineering, Darmstadt University of Technology, Petersenstr. 30, D-64287, Germany

Suad Jakirlic
Department of Mechanical Engineering Institute of Fluid Mechanics and Aerodynamics (SLA) / Center of Smart Interfaces (CSI) Technische Universitat Darmstadt Petersenstrasse 17, D-64287 Darmstadt, Germany

Kemal Hanjalic
Department of Physics, Novosibirsk State University (NSU), 1, Pirogov Str., Novosibirsk, 630090, Russia; Faculty of Applied Sciences, Delft University of Technology (TU Delft), Building 58, Van der Maasweg 9, 2629 HZ, Delft, The Netherlands

Sinopsis

Turbulent flow over a backward-facing step (ReH = 5540; ER = 1.5) subjected to large temperature gradients originating from an increasingly enhanced heat flux through the step wall is investigated computationally by using a near-wall Second-Moment Closure model (SMC) in the RANS (Reynolds-averaged Navier-Stokes) framework and a hybrid LES/RANS (HLR) scheme. Reference Large Eddy Simulations (LES) were performed by Avancha and Pletcher (2002). Corresponding isothermal flow was investigated experimentally by Kasagi and Matsunaga (1995). The results obtained by present simulations follow closely the reference database, especially for the mean velocity evolution and the bulk and wall temperature variations. An important outcome of the present study is a substantial increase of the friction coefficient with the increase in the wall heating both in the flow reversal and recovery region, associated with the local flow acceleration in the immediate wall vicinity.