Research Activities

High-speed flows over rough walls

Turbulent boundary layers on high-speed vehicles can be significantly affected by surface roughness. Although flight systems are designed to be relatively smooth, roughness can appear or develop for various reasons: pitting, corrosion, spallation or contamination deposits alter the surface locally, while tiled thermal protection systems exhibit seams and steps over large areas. Roughness interacts with the incoming turbulent boundary layer, strongly increasing drag and heat transfer. Owing to the complexity of supersonic and hypersonic flows, the additional impact of roughness has rarely been studied. We explore it with high-fidelity simulations of boundary layers over distributed roughness, from subsonic to hypersonic conditions (PRACE project LEISURE, 2020; EuroHPC Extreme Access project CREST on LUMI-G, 2025), and we use the resulting data to assess the Reynolds analogy and to develop wall models for rough high-speed flows. The DNS databases of supersonic and hypersonic boundary layers produced by the group are publicly available and used as reference data by the community.

Related publications:

D. Modesti, S. Sathyanarayana, F. Salvadore, M. Bernardini, J. Fluid Mech. 942, A44 (2022) — doi:10.1017/jfm.2022.393
M. Cogo, D. Modesti, M. Bernardini, F. Picano, J. Fluid Mech. 1009, A56 (2025) — doi:10.1017/jfm.2024.1232
M. Cogo, D. Modesti, F. Picano, M. Bernardini, J. Fluid Mech. 1025, A21 (2025) — doi:10.1017/jfm.2025.10935
M. Cogo, D. Depieri, M. Bernardini, F. Picano, J. Fluid Mech. 1039, A34 (2026) — doi:10.1017/jfm.2026.11842

Supersonic flow control and drag reduction

Micro-ramps are passive control devices that counteract the detrimental effects of shock-wave/boundary-layer interactions in supersonic inlets and transonic wings. Our direct numerical simulations unravel the complex flow organisation around the micro-ramp, which includes the formation of lateral counter-rotating vortices merging into the ramp wake and a fascinating train of vortex rings undergoing an azimuthal instability. These simulations clarify how such devices can be used to manipulate supersonic turbulent flows and control boundary-layer separation, and how their size and location affect the controlled interaction (EuroHPC Extreme Access project DISCOVERY on MareNostrum 5, 2024; Leonardo Early Access project DISCOVERER, 2023). We also study active control by streamwise-travelling waves of spanwise wall velocity, which reduce turbulent skin friction in the compressible regime, and drag reduction over superhydrophobic and liquid-infused surfaces.

Related publications:

G. Della Posta, M. Blandino, D. Modesti, F. Salvadore, M. Bernardini, J. Fluid Mech. 974, A44 (2023) — doi:10.1017/jfm.2023.764
F. Salvadore, A. Memmolo, D. Modesti, G. Della Posta, M. Bernardini, Phys. Rev. Fluids 8, 110508 (2023) — doi:10.1103/PhysRevFluids.8.110508
G. Della Posta, M. Fratini, F. Salvadore, M. Bernardini, AIAA J. 62(2), 542–556 (2024) — doi:10.2514/1.J063363
G. Della Posta, E. Martelli, F. Salvadore, M. Bernardini, J. Fluid Mech. 998, A12 (2024) — doi:10.1017/jfm.2024.742
M. Galante, G. Della Posta, E. Martelli, M. Bernardini, AIAA J. 64(6), 3078–3092 (2026) — doi:10.2514/1.J066012
F. Gattere, M. Zanolini, D. Gatti, M. Bernardini, M. Quadrio, J. Fluid Mech. 987, A30 (2024) — doi:10.1017/jfm.2024.408

Shock wave/boundary layer interaction

The interaction between shock waves and turbulent boundary layers is a central problem in aerospace research, as it occurs in a broad range of transonic, supersonic and hypersonic systems: supersonic inlets, transonic wings, rocket nozzles and control surfaces. Shock-wave/turbulent boundary-layer interactions (SBLIs) must be carefully considered in the design process, as they can harmfully affect the performance of aerospace systems by increasing aerodynamic drag and wall heat transfer and by triggering large-scale, low-frequency unsteadiness. We use direct numerical simulations to reproduce SBLIs under different conditions (Mach and Reynolds numbers, wall temperature, transitional and turbulent regimes) and to investigate the mechanisms behind their unsteadiness and heat-transfer amplification.

Related publications:

M. Bernardini, G. Della Posta, F. Salvadore, E. Martelli, J. Fluid Mech. 954, A43 (2023) — doi:10.1017/jfm.2022.1038
P.S. Volpiani, M. Bernardini, J. Larsson, Phys. Rev. Fluids 5, 014602 (2020) — doi:10.1103/PhysRevFluids.5.014602
M. Bernardini, I. Asproulias, J. Larsson, S. Pirozzoli, F. Grasso, Phys. Rev. Fluids 1, 084403 (2016) — doi:10.1103/PhysRevFluids.1.084403
F. De Vanna, M. Bernardini, F. Picano, E. Benini, Int. J. Heat Fluid Flow 98, 109071 (2022) — doi:10.1016/j.ijheatfluidflow.2022.109071

Aerodynamics and aeroacoustics of space launchers

The lift-off of space launch vehicles generates strong acoustic waves that interact in a complex and potentially dangerous way with the launch pad and the launcher itself. Engineering tools developed in the past have limited validity and cannot provide reliable predictions. It is therefore essential to develop and validate advanced computational models able to capture the transient flow induced by motor ignition. We use three-dimensional large-eddy simulations to predict the acoustic field produced by the lift-off of realistic launchers such as Vega and Vega C, with results that compare well with flight measurements despite the challenging operating conditions and geometry. The activity now extends, in collaboration with Roma Tre University, AVIO and ESA, to the transonic ascent and descent phases (buffeting, wall-pressure fluctuations, aeroacoustic loads on the FD1 demonstrator), to lift-off with water injection and to the VEGA-C/VEGA-E configurations, within ESA and AVIO research contracts (2021–2025).

Related publications:

G. Della Posta, E. Martelli, F. Stella, D. Barbagallo, A. Neri, F. Salvadore, M. Bernardini, Comput. Fluids 263, 105945 (2023) — doi:10.1016/j.compfluid.2023.105945
A. Di Marco et al., Aerosp. Sci. Technol. 168, 110765 (2026) — doi:10.1016/j.ast.2025.110765
G. Della Posta et al., Aerosp. Sci. Technol. 179, 113533 (2026) — doi:10.1016/j.ast.2026.113533
D. Palma, L. Pirillo, M. Bernardini, F. Stella, Int. J. Heat Fluid Flow 121, 110409 (2026) — doi:10.1016/j.ijheatfluidflow.2026.110409
R. Camussi et al., Aerosp. Sci. Technol. 99, 105772 (2020) — doi:10.1016/j.ast.2020.105772

Supersonic and hypersonic boundary layers

The study of high-speed turbulent boundary layers is essential to predict aerodynamic heating and drag on supersonic and hypersonic vehicles. The interest of the research community is fed by the development of vehicles capable of sustained hypersonic flight in the atmosphere, sub-orbital flight and planetary re-entry. We investigate the structure of high-speed, zero-pressure-gradient turbulent boundary layers at moderate-to-high Reynolds numbers through direct numerical simulation of the Navier–Stokes equations, assessing the effects of Mach number and wall heat transfer on turbulence statistics, compressibility transformations and wall-pressure fluctuations.

Related publications:

M. Cogo, F. Salvadore, F. Picano, M. Bernardini, J. Fluid Mech. 945, A30 (2022) — doi:10.1017/jfm.2022.574
M. Cogo, U. Baù, M. Chinappi, M. Bernardini, F. Picano, J. Fluid Mech. 974, A10 (2023) — doi:10.1017/jfm.2023.791
S. Pirozzoli, M. Bernardini, J. Fluid Mech. 688, 120–168 (2011) — doi:10.1017/jfm.2011.368

Wind energy

To reduce the cost of wind energy, rotor diameters now exceed 200 m. For such long and flexible blades, fluid–structure interaction plays a significant role in the design of the turbine. Given the difficulty of measuring these phenomena, high-fidelity numerical models combining computational fluid and structural dynamics are needed. With the University of Texas at Dallas we developed an aeroelastic model for wind turbines that couples a three-dimensional LES solver with a modal beam-like structural solver, and improved the description of the local blade aerodynamics with a semi-empirical model for dynamic-stall hysteresis.

Related publications:

G. Della Posta, S. Leonardi, M. Bernardini, Wind Energy 26(1), 98–125 (2023) — doi:10.1002/we.2789
G. Della Posta, S. Leonardi, M. Bernardini, Renew. Energy 190, 971–992 (2022) — doi:10.1016/j.renene.2022.03.158

Rocket nozzles and solid rocket motors

Rocket nozzles operating at over-expanded conditions exhibit flow separation and shock unsteadiness that generate dangerous side loads; solid rocket motors are prone to vortex shedding and pressure oscillations coupled with the internal acoustics. We investigate these phenomena with scale-resolving simulations (LES, DES and DNS) on realistic geometries, including dual-bell nozzles and full-scale motors, using immersed-boundary methods to handle complex and moving boundaries. The results support the design of the propulsion systems of European launchers, in collaboration with AVIO, ESA (thrust unsteadiness of large solid rocket motors) and the University of Campania.

Related publications:

E. Martelli, L. Saccoccio, P.P. Ciottoli, C.E. Tinney, W.J. Baars, M. Bernardini, J. Fluid Mech. 895, A29 (2020) — doi:10.1017/jfm.2020.280
M. Cimini, E. Martelli, M. Bernardini, Flow Turbul. Combust. 107, 551–574 (2021) — doi:10.1007/s10494-021-00243-4
M. Bernardini, M. Cimini, F. Stella, E. Cavallini et al., AIAA J. 58(12), 5191–5201 (2020) — doi:10.2514/1.J058866
A. Di Mascio, E. Martelli, M. Bernardini, F. Stella, A. Neri, AIAA J. 61(5), 2314–2318 (2023) — doi:10.2514/1.J062554
E. Martelli, P.P. Ciottoli, L. Saccoccio, F. Nasuti, M. Valorani, M. Bernardini, AIAA J. 57(1), 239–251 (2019) — doi:10.2514/1.J057162

Planetary entry: capsules and supersonic parachutes

Entry, descent and landing on Mars rely on blunt capsules decelerated by supersonic parachutes deployed in the turbulent wake of the vehicle. We study the unsteady supersonic flow around entry capsules at different angles of attack and the coupled dynamics of the capsule–parachute system with large-eddy simulations, in collaboration with the University of Padova, with the aim of understanding the flight instabilities observed during supersonic descent. The activity is supported by the PRIN 2022 project ADMIRE (ADvanced Modeling of hIgh-speed aerodynamics for MaRs Entry, national PI) and by the PRACE STOMP (2022) and ISCRA SPEAR (2024) allocations.

Related publications:

L. Placco, M. Cogo, M. Bernardini, A. Aboudan, F. Ferri, F. Picano, Aerosp. Sci. Technol. 143, 108709 (2023) — doi:10.1016/j.ast.2023.108709
L. Placco, G. Soldati, M. Bernardini, F. Picano, Aerosp. Sci. Technol. 160, 110026 (2025) — doi:10.1016/j.ast.2025.110026

Cryogenic propellant tanks

Cryogenic propellants stored in launcher and spacecraft tanks experience self-pressurisation, active pressurisation and sloshing, phenomena that must be predicted accurately under both ground and reduced-gravity conditions. In collaboration with ASI and AVIO we develop and validate CFD methodologies for the thermodynamics of cryogenic tanks, including phase change at the liquid–vapour interface and the damping of lateral sloshing by anti-sloshing devices.

Related publications:

F. Rossetti, M. Pizzarelli, R.C. Pellegrini, E. Cavallini, M. Bernardini et al., Cryogenics 147, 104059 (2025) — doi:10.1016/j.cryogenics.2025.104059
F. Rossetti, M. Pizzarelli, R.C. Pellegrini, E. Cavallini et al., Cryogenics 144, 103959 (2024) — doi:10.1016/j.cryogenics.2024.103959

STREAmS and exascale computing

STREAmS is our open-source solver for the direct numerical simulation of compressible turbulent flows on GPUs. Developed with CINECA, it runs on NVIDIA, AMD and Intel accelerators through CUDA Fortran, OpenMP offload and HIP back-ends, it is adopted by research groups worldwide and it has demonstrated excellent scalability on the largest European systems (LUMI-G, MareNostrum 5, Leonardo); in 2025 our EuroHPC project was admitted to the JUPITER Research and Early Access Program towards exascale. Version 2 introduced curvilinear grids, in situ visualisation and new physical models, enabling simulations with tens of billions of grid points. The development is supported by the ENEA PTR programme, by the Centres of Excellence EXCELLERAT and CERISSE-X and by the ICSC National Centre. Read more on the Software page.

Related publications:

M. Bernardini, D. Modesti, F. Salvadore, S. Pirozzoli, Comput. Phys. Commun. 263, 107906 (2021) — doi:10.1016/j.cpc.2021.107906
M. Bernardini, D. Modesti, F. Salvadore, S. Sathyanarayana, G. Della Posta, S. Pirozzoli, Comput. Phys. Commun. 285, 108644 (2023) — doi:10.1016/j.cpc.2022.108644
F. Salvadore, G. Soldati, A. Ceci, G. Rossi et al., Comput. Phys. Commun. 314, 109652 (2025) — doi:10.1016/j.cpc.2025.109652
S. Sathyanarayana, M. Bernardini, D. Modesti, S. Pirozzoli, F. Salvadore, J. Parallel Distrib. Comput. 196, 104993 (2025) — doi:10.1016/j.jpdc.2024.104993
F. Salvadore, G. Rossi, S. Sathyanarayana, M. Bernardini, J. Supercomput. 80, 21094–21127 (2024) — doi:10.1007/s11227-024-06254-y

Turbulent combustion and reacting flows

A recent line of activity extends our high-fidelity tools to reacting flows: large-eddy simulation of supersonic combustion in scramjet engines (HyShot II combustor), the development of a compressible multicomponent reactive solver based on STREAmS-2, and the simulation of ammonia/hydrogen combustion in MILD regime for gas turbines, in collaboration with ENEA (PTR 2025–2027 programme) and ESA (turbulent reacting multiphase flows).

Related publications:

M. Fratini, G. Della Posta, M. Bernardini, "Large eddy simulation of the HyShot II combustor", THMT-25 (2025) — doi:10.1615/THMT-25.330
"Development and validation of a compressible multicomponent reactive flow solver based on STREAmS-2.0", EUCASS 2025.

Computing resources and funding

Our simulations run on CINECA systems (ISCRA programme, Leonardo Early Access) and on EuroHPC machines — LUMI-G, MareNostrum 5 and JUPITER — through PRACE and EuroHPC Extreme Access allocations, and on the ESA Space HPC facility. Research is funded by the European Union (Horizon Europe Centres of Excellence EXCELLERAT and CERISSE-X; PNRR National Centre ICSC), by the Italian Ministry of University and Research (PRIN 2022 ADMIRE, SIR), by ESA, ASI, AVIO, ENEA, Regione Lazio and Sapienza University of Rome.

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