88 citations · 381 across the 16 of their papers we have counts for
16 papers
Critical assessment of RANS Models for Turbulent Heat Transfer in Low-Prandtl-Number Forced Convection
Luca Marocco, Jonathan Schmitt, Jonathan Neuhauser +2
RANS modeling of turbulent heat transfer in liquid metals remains challenging because the very low Prandtl number weakens the similarity between momentum and thermal transport. Sev…
Prediction of equivalent sand-grain size and identification of drag-relevant scales of roughness -- a data driven approach
Jiasheng Yang, Alexander Stroh, Sangseung Lee +3
The purpose of the present work is to examine two possibilities; firstly, predicting equivalent sand-grain roughness size based on the roughness height probability density fu…
The effect of spanwise heterogeneous surfaces on mixed convection in turbulent channels
K. Schäfer, B. Frohnapfel, J. P. Mellado
Turbulent mixed convection in channel flows with heterogeneous surfaces is studied using direct numerical simulations. The relative importance between buoyancy and shear effects, c…
Tripping and laminar--turbulent transition: Implementation in RANS--EVM
N. Tabatabaei, G. Fahland, A. Stroh +5
Fundamental fluid--mechanics studies and many engineering developments are based on tripped cases. Therefore, it is essential for CFD simulations to replicate the same forced trans…
Objective barriers to the transport of dynamically active vector fields
George Haller, Stergios Katsanoulis, Markus Holzner +2
We derive a theory for material surfaces that maximally inhibit the diffusive transport of a dynamically active vector field, such as the linear momentum, the angular momentum or t…
Rearrangement of secondary flow over spanwise heterogeneous roughness
A. Stroh, K. Schäfer, B. Frohnapfel +1
Turbulent flow over a surface with streamwise-elongated rough and smooth stripes is studied by means of direct numerical simulation (DNS) in a periodic plane open channel with full…
Assessment of skin-friction-reduction techniques on a turbulent wing section
M. Atzori, R. Vinuesa, A. Stroh +2
The scope of the present project is to quantify the effects of uniform blowing and body-force damping on turbulent boundary layers subjected to a non-uniform adverse-pressure-gradi…
Global energy fluxes in fully-developed turbulent channels with flow control
Davide Gatti, Andrea Cimarelli, Yosuke Hasegawa +2
This paper addresses the integral energy fluxes in natural and controlled turbulent channel flows, where active skin-friction drag reduction techniques allow a more efficient use o…
A systematic study of turbulent heat transfer over rough walls
Pourya Forooghi, Matthias Stripf, Bettina Frohnapfel
Direct Numerical Simulations are used to solve turbulent flow and heat transfer over a variety of rough walls in a channel. The wall geometries are exactly resolved in the simulati…
Direct Numerical Simulation of Turbulent Channel Flow with Riblets at Low Reynolds Number
Verena Fink, Bettina Frohnapfel
In this report we briefly summarize the set-up and results for direct numerical simulations (DNS) of turbulent channel flows with riblets. The DNS are carried out with OpenFOAM whi…
Small scale dynamics of a shearless turbulent/non-turbulent interface in dilute polymer solutions
Giacomo Cocconi, Elisabetta De Angelis, Bettina Frohnapfel +2
We study the physics of turbulent/non-turbulent interface of an isolated turbulent region in dilute polymer solutions and Newtonian fluid. The performance of a FENE-P model with a…
Global effect of local skin friction drag reduction in spatially developing turbulent boundary layer
A. Stroh, Y. Hasegawa, P. Schlatter +1
A numerical investigation of two locally applied drag reducing control schemes is carried out in the configuration of a spatially developing turbulent boundary layer (TBL). One con…
Does the choice of the forcing term affect flow statistics in DNS of turbulent channel flow?
Maurizio Quadrio, Bettina Frohnapfel, Yosuke Hasegawa
We seek possible statistical consequences of the way a forcing term is added to the Navier--Stokes equations in the Direct Numerical Simulation (DNS) of incompressible channel flow…
Numerical simulation of turbulent duct flows with constant power input
Yosuke Hasegawa, Maurizio Quadrio, Bettina Frohnapfel
The numerical simulation of a flow through a duct requires an externally specified forcing that makes the fluid flow against viscous friction. To this aim, it is customary to enfor…
Prediction of turbulence control for arbitrary periodic spanwise wall movement
Andrea Cimarelli, Bettina Frohnapfel, Yosuke Hasegawa +2
In order to generalize the well-known spanwise-oscillating-wall technique for drag reduction, non-sinusoidal oscillations of a solid wall are considered as a means to alter the ski…
Money versus Time: Evaluation of Flow Control in Terms of Energy Consumption and Convenience
Bettina Frohnapfel, Yosuke Hasegawa, Maurizio Quadrio
Flow control with the goal of reducing the skin friction drag on the fluid-solid interface is an active fundamental research area, motivated by its potential for significant energy…