Wall-modeled LES of the flow inside an aircraft engine compressor ONERA CFD 2023-02-03 | Wall-modeled LES of the CREATE compressor with labyrinths, designed by Safran Aircraft Engines. Simulation performed by ONERA.A hybrid curvilinear/Cartesian mesh with 1.46 billion cells is used to simulate the turbulent compressible flow in the 3.5 stage high-pressure CREATE compressor. The channel is discretized with structured curvilinear grids, whereas the labyrinth is handled by Cartesian meshes and immersed boundary method (IBM) (10.1016/j.jcp.2021.110240).The simulation is performed on 656 Intel Broadwell cores and requires 58,000 CPU hours (less than 4 days) to compute a full 360° revolution.Post-processing and flow images are made with Cassiopée ( https://cassiopee.onera.fr ).The Fast solver ( https://fast.onera.fr) is used to run the LES simulation.Author: Ivan Mary ( ONERA/DAAA, https://www.onera.fr/en/daaa )
Large Eddy Simulation of a Quadcopter Drone in Hover ONERA CFD 2024-04-29 | Large Eddy Simulation simulation of a complete drone in hovering flight.Regions close to the rotors are discretized with body fitted grids rotating in an off-body Cartesian grid thanks to the overset grids method.Each rotor grid comprises 58 million points and the background grid contains 2.2 billion points.The fuselage is taken into account within the computational domain as an immersed boundary (IBM).The rotation speed corresponds to a very light-weight fuselage (70g).The Cartesian mesh is stretched far away from the Cartesian core to save on the number of points, with coarser cells at the external borders."Post-processing and flow images are generated in parallel with Cassiopee ( https://cassiopee.onera.fr ).ONERA FAST solver ( https://fast.onera.fr ) is used to run the LES simulation.The simulation is performed on 1120 Intel Broadwell cores.Authors: A. Dorange, C. Benoit and B. Constant (ONERA/DAAA, https://www.onera.fr/en/daaa )
High fidelity CFD simulation around a three-bladed light propeller ONERA CFD 2023-10-23 | CFD simulation of ONERA HAD-1 propeller using structured overset grids.Q-criterion isosurface shows vortices structures in the flow.Numerical Schlieren shows the creation of acoustic waves and their propagation.The overset mesh is made of curvilinear grids around the blades and the spinner and an off-body Cartesian mesh for a total of 1.5 billion points. ZDES (RANS/LES) model is used to model turbulence.Post-processing and flow images are made with Cassiopée ( https://cassiopee.onera.fr ).ONERA FAST solver ( https://fast.onera.fr) is used to run the ZDES simulation.The present work was performed in the framework of the joint research project INPRO with the support of the French Civil Aviation Authority as part of the "Plan National de Relance et de Résilience français" (PNRR) and of the New Generation EU recovery plan.Author: C. Benoit, B. Constant and A. Dorange ( ONERA/DAAA, https://www.onera.fr/en/daaa )
High fidelity CFD simulation of helicopter rotor in forward flight ONERA CFD 2022-07-26 | Hybrid RANS-LES simulation using chimera method performed on the 7A helicopter rotor in high speed forward flight (mu = 0.4, Mtip = 0.6462). Each blade mesh contains 5 million points and the background grid contains 4.1 billion points. 1536 CPU cores were used to run this simulation. A revolution is achieved in 24h. The video shows a Q criteria iso surface of value 5000 colored with vorticity magnitude.Post-processing and flow images have been made with Cassiopée ( https://cassiopee.onera.fr ).The Fast solver ( https://fast.onera.fr ) is used to run the RANS-LES simulation with AUSM scheme on Cartesian grids and Roe scheme on blade grids.Simulation and video realized by Baptiste Méral.
DNS of a hypersonic transitional shockwave-boundary layer interaction ONERA CFD 2021-10-21 | Direct Numerical Simulation of a hypersonic transitional shockwave-boundary layer interaction on an axisymmetric compression ramp. The flow conditions are : M=5, ReL=1.1 million, Pi=4.14Bar, Ti=574K. The simulation is a reproduction of an experiment conducted in the ONERA R2Ch blowdown facility.Mesh generation and pre/post-processing are performed by Cassiopée ( https://cassiopee.onera.fr ). The Fast solver ( https://fast.onera.fr ) is used to run the DNS simulation, with an explicit rk3 time integration (timestep of 8ns) and a new low dissipation shock capturing second order scheme. The computation is performed on 2200 cores thanks to an allocation by ONERA/DSI on a structured grid of 757 million elements.Reference:Lugrin, M., Beneddine, S., Leclercq, C., Garnier, E., & Bur, R. (2021). Transition scenario in hypersonic axisymmetrical compression ramp flow. Journal of Fluid Mechanics, 907.Author: M. Lugrin (ONERA)
Numerical analysis of wake interactions on a high speed compound helicopter at moderate speed ONERA CFD 2021-07-20 | In the context of the development of high-speed compound helicopters, the main rotor may not be an efficient propulsive device at high speeds and adding a propulsive propeller is a means to enable higher speed. On such configuration, at low speed, the propellers are in strong interactions with the main rotor wake which affects their performance and aircraft maneuverability.Aerodynamic interactions of the wakes from a main rotor and a propeller at moderate speed conditions (advance ratio 0.15) are investigatedbased on CFD computations.3D URANS computations with elsA CFD solver ( http://elsa.onera.fr )Co-processing with Cassiopee ( https://cassiopee.onera.fr )Part of this work was granted access to the HPC resources of CINES under the allocation 2017-A0032A10264 made by GENCI.R. Boisard "Aerodynamic investigation of rotor / propeller interactions on a fast rotorcraft", 44th European rotorcraft forum, Delft, Netherland, September 18-21, 2018. ( http://hdl.handle.net/20.500.11881/3996 )R. Boisard, J. W. Lim, "Aerodynamic Analysis of Rotor/Propeller Wakes Interactions on High Speed Compound Helicopter", 47th European rotorcraft forum, Virtual conference, September 7-9, 2021.Author: R. Boisard (ONERA)
Numerical analysis of wake interactions on a high speed compound helicopter at low speed ONERA CFD 2021-07-20 | In the context of the development of high-speed compound helicopters, the main rotor may not be an efficient propulsive device at high speeds and adding a propulsive propeller is a means to enable higher speed. On such configuration, at low speed, the propellers are in strong interactions with the main rotor wake which affects their performance and aircraft maneuverability.Aerodynamic interactions of the wakes from a main rotor and a propeller at low speed conditions (advance ratio 0.05) are investigated based on CFD computations.3D URANS computations with elsA CFD solver (http://elsa.onera.fr)Co-processing with Cassiopee (https://cassiopee.onera.fr)Part of this work was granted access to the HPC resources of CINES under the allocation 2017-A0032A10264 made by GENCI.R. Boisard "Aerodynamic investigation of rotor / propeller interactions on a fast rotorcraft", 44th European rotorcraft forum, Delft, Netherland, September 18-21, 2018. (http://hdl.handle.net/20.500.11881/3996)R. Boisard, J. W. Lim, "Aerodynamic Analysis of Rotor/Propeller Wakes Interactions on High Speed Compound Helicopter", 47th European rotorcraft forum, Virtual conference, September 7-9, 2021.Author: R. Boisard (ONERA)
Numerical analysis of wake interactions on a high speed compound helicopter in hover ONERA CFD 2021-07-20 | In the context of the development of high-speed compound helicopters, the main rotor may not be an efficient propulsive device at high speeds and adding a propulsive propeller is a means to enable higher speed. On such configuration, at low speed, the propellers are in strong interactions with the main rotor wake which affects their performance and aircraft maneuverability.Aerodynamic interactions of the wakes from a main rotor and a propeller in hover conditions are investigated based on CFD computations.3D URANS computations with elsA CFD solver (http://elsa.onera.fr)Co-processing with Cassiopee (https://cassiopee.onera.fr)Part of this work was granted access to the HPC resources of CINES under the allocation 2017-A0032A10264 made by GENCI.R. Boisard "Aerodynamic investigation of rotor / propeller interactions on a fast rotorcraft", 44th European rotorcraft forum, Delft, Netherland, September 18-21, 2018. (http://hdl.handle.net/20.500.11881/3996)R. Boisard, J. W. Lim, "Aerodynamic Analysis of Rotor/Propeller Wakes Interactions on High Speed Compound Helicopter", 47th European rotorcraft forum, Virtual conference, September 7-9, 2021.Author: R. Boisard (ONERA)
LES of a swirled pressurized ethylene air flame with Lagrangian soot tracking (CEDRE) ONERA CFD 2019-08-27 | Numerical simulation of the FIRST (Fuel Injector Research for Sustainable Transport) configuration, experimentally investigated at DLR, with the ONERA CEDRE code. The numerical simulation is performed by coupling the CEDRE/CHARME fluid mechanics solver and CEDRE/SPARTE Lagrangian dispersed phase solver. The flame - identified on the left by an isosurface of heat release (orange) - is stabilized by an inner recirculation zone. Soot particles are produced in the lower part of the chamber and oxidized in the upper part, partly through secondary air injection - identified on the left by an isosurface of oxygen mass fraction (blue) - which reproduces the behavior of RQL (Rich burn, Quick-mix, Lean burn) aeronautical combustors. Experimental and numerical time-averaged fields of the soot volume fraction (in ppm) are compared on the right and show a good agreement.
Large-Eddy Simulation of a multi-element wing section ONERA CFD 2019-06-17 | LEISA2 test case from AIAA BANC workshops: Mach number=0.178, AoA=6.15°, Reynolds number=1.23e6The multi-element wing section is modeled with immersed boundary conditions (IBC).Automatic Cartesian mesh generation and IBC pre-processing are performed by Cassiopée ( https://cassiopee.onera.fr ). The Fast solver ( https://fast.onera.fr ) is used to run the LES simulation with AUSM scheme.Author: T. Renaud (ONERA)
Simulation of VEGA launcher liftoff with CEDRE ONERA CFD 2019-03-12 | The video shows the numerical simulation of VEGA launcher liftoff, performed with CHARME fluid mechanics solver included in ONERA CEDRE simulation platform for energetics. The nozzle jet rushes into the exhaust flue for burnt gases, from where the exhaust plume gets out, here colored by the temperature (in Kelvin). The balance of aerodynamic forces applied on all surfaces of the vehicle enables to calculate its acceleration. From a numerical point of view, the mesh linked to the launcher follows the motion deducted from that acceleration. It intersects with the background mesh leading at each time step to an adapted domain discretization, ensuring this way a fully conservative computation.
Aerodynamic behavior of the NREL 5-MW floating offshore wind turbine ONERA CFD 2019-02-22 | The flowfield around the rotor blades of a wind turbine may be quite complex to predict, due to the occurrence of several aerodynamic phenomena. It is all the more true for floating offshore wind turbines (FOWT), for which the six rigid-body motions of the floating platform can induce blade/wake interactions. Therefore conventional numerical approaches for wind turbine applications, such as BEM, may be questionable for an accurate prediction of floating wind turbine aerodynamic loads. The aerodynamic behavior of the NREL 5-MW subjected to a prescribed pitch motion is here investigated based on CFD simulations.3D URANS computations with elsA CFD solver ( http://elsa.onera.fr )Co-processing with Cassiopee ( https://cassiopee.onera.fr )Most of this work was granted access to the HPC resources of CINES under the allocation2018-A0032A10280 made by GENCI.Caroline Lienard, Ronan Boisard, and Camille Daudin. "Aerodynamic behavior of a floating offshore wind turbine", AIAA Scitech 2019 Forum, AIAA SciTech Forum, (AIAA 2019-1575)doi.org/10.2514/6.2019-1575Music : The Time To Run (Finale) by Dexter Britain (http://www.dexterbritain.co.uk), Creative Commons Licence.Author: C. Lienard, R. Boisard (ONERA)
Direct Numerical Simulation of a wing profile ONERA CFD 2018-12-11 | 1 billion points DNS (Direct Numerical Simulation) on a NACA4412 profile at 5 degrees angle of attack. Reynolds number is 350000 per airfoil chord and Mach number is 0.117. Both upper and lower turbulent boundary layers are tripped respectively at 15% and 50% by roughness elements evenly spaced in the boundary layer created by a zonal immersed boundary condition (Journal of Computational Physics, Volume 363, 15 June 2018, Pages 231-255, sciencedirect.com/science/article/pii/S0021999118301104). The spanwise extent is 0.3*chord. The computation has been performed on a structured multiblock mesh with the FastS compressible flow solver developed by ONERA on 1064 MPI cores ( https:/fast.onera.fr ). The video shows the early stages of the calculation (equivalent to 40000 time steps) highlighting the spatial development of fine-scale turbulence in both attached boundary layer and free wake.Post-processing and flow images have been made with Cassiopée ( https://cassiopee.onera.fr ).Soundtrack is royalty-free.Author: V. Gleize (ONERA)
Flow past a cylinder at Re=3900 with immersed boundary conditions ONERA CFD 2018-10-04 | 3D LES simulation of turbulent flow past a cylinder at Reynolds number Re=3900. The cylinder wall is modeled by immersed boundary conditions (IBC) with a resolution of 0.003*d (d is the cylinder diameter). Farfield conditions are set at 500*d and the wake is refined till 6*d. The spanwise length of the cylinder is equal to pi*d. The mesh contains 90M points. Automatic octree mesh generation and IBC pre-processing are performed by Cassiopée ( https://cassiopee.onera.fr ). The Fast solver ( https://fast.onera.fr ) is used to run the simulation with AUSM scheme.More information in AIAA paper 2019-2179 (AIAA Scitech, January 2019, San Diego): "Validation of an immersed boundary method for compressible flows"Author: T. Renaud (ONERA)
Aerodynamic investigation of a helicopter rotor hovering in the vicinity of a building ONERA CFD 2018-09-24 | 3D URANS computation with elsA solver ( http://elsa.onera.fr ).The building is modelled by IBC (immersed boundary conditions) in the simulation.Part of Garteur AG22 project ( http://www.garteur.org/Helicopters.html )Publication: "Aerodynamic investigation of a helicopter rotor hovering in the vicinity of a building", R. Boisard, AHS International 74th Annual Forum & Technology Display, Phoenix, Arizona, USA, May 14-17, 2018.Author: R. Boisard (ONERA)
Hovering rotor in ground effect interacting with a square yard ONERA CFD 2017-12-20 | 3D URANS computation with elsA solver (http://elsa.onera.fr).The square building is modelled by IBC (immersed boundary conditions) in the simulation.Part of Garteur AG22 project (http://www.garteur.org/Helicopters.html)Publication: "Experimental and numerical investigation of the aerodynamic interactions between a hovering helicopter and surrounding obstacles", Q. Gallas, R. Boisard, JC. Monnier, J. Privost, A. Gilliot, ERF2017, 12-15 septembre 2017, Milan, ItalyAuthor: R. Boisard (ONERA)
CFD simulation of a wind turbine in offshore floating configuration ONERA CFD 2017-09-16 | 3D URANS computation with elsA CFD solver ( http://elsa.onera.fr ) of a wind turbine in pitching motion.Co-processing with Cassiopee ( https://cassiopee.onera.fr ).Author: C. Lienard, R. Boisard (ONERA)
CFD simulation of Dewoitine 551 ONERA CFD 2017-06-14 | 3D URANS computation with elsA CFD solver ( http://elsa.onera.fr ) of the World War II airplane Dewoitine 551.Co-processing with Cassiopee ( https://cassiopee.onera.fr ).Author: G. Delattre (ONERA)
Taylor Green Vortex ONERA CFD 2017-01-11 | Numerical simulation of Navier-Stokes equations for a Taylor Green Vortex at Reynolds 1600.Computed with ONERA elsA solver or Fast solver ( https://fast.onera.fr ), in-situ and in-memory post-processing and visualisation with Cassiopee ( https://cassiopee.onera.fr ).Cartesian mesh 256x256x256.Order 2 numerical scheme.Enstrophy (left), Q criteria slice, Q criteria isosurface colored by Vorticity magnitude (right).Author: T. Renaud (ONERA)
CFD computation of helicopter fuselage and soft rotor ONERA CFD 2016-09-30 | Aerodynamic simulation of a helicopter in forward flight with fluid/structure coupling on the main rotor blades.ONERA simulated the aerodynamics of a helicopter in cruise flight with the ONERA CFD solver elsA. The simulation was carried out on ONERA supercomputers. The control of the main rotor and the deformation of the blades are provided by a rotorcraft comprehensive analysis, coupled to elsA. Numerical predictions were validated by comparison with wind tunnel measurements.This research received funding from the Airbus-Safran-ONERA Agreement.Author: B. Ortun (ONERA)
CFD computation of an open rotor ONERA CFD 2016-09-23 | CFD simulations performed with the ONERA elsA solver of counter-rotating open rotors. The numerical results are compared to wind tunnel tests (TsAGi).The research leading to these results has received funding from the European Union Seventh Framework Program.Author: R. Boisard (ONERA)
Dynamic stall of a model helicopter blade by CFD ONERA CFD 2016-08-26 | Computation performed by ONERA on GENCI super-computers with FAST CFD code ( https://fast.onera.fr ).Post-processing with Cassiopee ( https://cassiopee.onera.fr ).Author: I. Mary (ONERA)
