Reynolds number effects in shock-wave/turbulent boundary-layer interactions

L. Laguarda, S. Hickel, F.F.J. Schrijer, B.W. van Oudheusden (2024)
Journal of Fluid Mechanics 989: A20. doi: 10.1017/jfm.2024.361

We investigate Reynolds number effects in strong shock-wave/turbulent-boundary layer interactions (STBLI) by leveraging a new database of wall-resolved and long-integrated large-eddy simulations (LES). The database encompasses STBLI with massive boundary-layer separation at Mach 2.0, impinging-shock angle 40° and friction Reynolds numbers Re_τ = 355, Re_τ = 1226, and Re_τ = 5118.

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Passive stabilization of crossflow instabilities by a reverse lift-up effect

J. Casacuberta, S. Hickel, M. Kotsonis (2024)
Physical Review Fluids 9: 034903. doi: 10.1103/PhysRevFluids.9.043903

A novel mechanism is identified, through which a spanwise-invariant surface feature (a two-dimensional forward-facing step) significantly stabilizes the stationary crossflow instability of a three-dimensional boundary layer. The mechanism is termed here as reverse lift-up effect, inasmuch as it acts reversely to the classic lift-up effect; that is, kinetic energy of an already-existing shear-flow instability is transferred to the underlying laminar flow through the action of cross-stream perturbations.

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Large eddy simulations of reacting and non-reacting transcritical fuel sprays using multiphase thermodynamics

M. Fathi, S. Hickel, D. Roekaerts (2022)
Physics of Fluids 34: 085131. doi: 10.1063/5.0099154

We present a novel framework for high-fidelity simulations of inert and reacting sprays with highly accurate and computationally efficient models for complex real-gas effects in high-pressure environments, especially for the hybrid subcritical/supercritical mode of evaporation during the mixing of fuel and oxidizer at transcritical conditions.

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Adaptive reduced-order modeling for non-linear fluid-structure interaction

A. Thari, V. Pasquariello, N. Aage, S. Hickel (2021)  
Computers and Fluids 229: 105099. doi: 10.1016/j.compfluid.2021.105099

We present an adaptive reduced-order model for the efficient time-resolved simulation of fluid–structure interaction problems with complex and non-linear deformations. The model is based on repeated linearizations of the structural balance equations. Upon each linearization step, the number of unknowns is strongly decreased by using modal reduction, which leads to a substantial gain in computational efficiency.

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Our group is organizing DLES15 in Delft on 20-22 May 2026!

The 15th ERCOFTAC Workshop on Direct and Large-Eddy Simulation will be held in Delft, The Netherlands, from 20 to 22 May 2026. Building on a long-standing and highly regarded series within the ERCOFTAC community, DLES15 will bring together researchers and practitioners working on Direct Numerical Simulation (DNS) and Large-Eddy Simulation (LES) of turbulent flows. While traditionally called a workshop, DLES has evolved into a full-fledged international conference, offering a rich scientific program and ample opportunities for in-depth discussion. 

Topics will include, but are not limited to: Advanced numerical methods and algorithms for LES and DNS; High-performance computing on present and next-gen hardware; Novel models for transition, turbulence, heat and mass transfer, reactive and multiphase flows; Data analysis, data assimilation, reduced-order modeling, and machine learning; Applications of DNS, LES, and hybrid methods in engineering, biological, medical, environmental, geophysical and astrophysical flows; Fundamental theories informed by insights from DNS and LES. 

Please save the date and visit the conference website for more information. We are looking forward to seeing you all in Delft!

Join us at ETMM15 in Dubrovnik on 22-24 September 2025.

For the 15th International ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurements (ETMM15), marking the 35th anniversary of the ETMM conference series, we return to the ETMM origins in Croatia. Please save the date and follow the ETMM website for more information.

AIAA Applied Aerodynamics Best Paper Award!

AIAA liked our paper on GPU-accelerated simulations for eVTOL aerodynamic analysis. Happy and proud to have contributed one more step towards sustainable high-speed regional air mobility for people and goods, the all-electric vertical take-off and landing Lilium Jet.