- Видео 22
- Просмотров 176 296
ONERA CFD
Добавлен 23 июн 2016
ONERA CFD productions
Large Eddy Simulation of a Quadcopter Drone in Hover
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 ( cassi...
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 ( cassi...
Просмотров: 2 485
Видео
High fidelity CFD simulation around a three-bladed light propeller
Просмотров 4,4 тыс.10 месяцев назад
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 mode...
Wall-modeled LES of the flow inside an aircraft engine compressor
Просмотров 11 тыс.Год назад
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 ...
High fidelity CFD simulation of helicopter rotor in forward flight
Просмотров 23 тыс.2 года назад
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 m...
DNS of a hypersonic transitional shockwave-boundary layer interaction
Просмотров 3,3 тыс.2 года назад
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 ( cassiopee.onera.fr ). The Fast ...
Numerical analysis of wake interactions on a high speed compound helicopter at moderate speed
Просмотров 1,3 тыс.3 года назад
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 interact...
Numerical analysis of wake interactions on a high speed compound helicopter at low speed
Просмотров 4263 года назад
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 interact...
Numerical analysis of wake interactions on a high speed compound helicopter in hover
Просмотров 7433 года назад
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 interact...
LES of a swirled pressurized ethylene air flame with Lagrangian soot tracking (CEDRE)
Просмотров 1,2 тыс.5 лет назад
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...
Large-Eddy Simulation of a multi-element wing section
Просмотров 22 тыс.5 лет назад
LEISA2 test case from AIAA BANC workshops: Mach number=0.178, AoA=6.15°, Reynolds number=1.23e6 The multi-element wing section is modeled with immersed boundary conditions (IBC). Automatic Cartesian mesh generation and IBC pre-processing are performed by Cassiopée ( cassiopee.onera.fr ). The Fast solver ( fast.onera.fr ) is used to run the LES simulation with AUSM scheme. Author: T. Renaud (ONE...
Simulation of VEGA launcher liftoff with CEDRE
Просмотров 2,9 тыс.5 лет назад
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...
Aerodynamic of the NREL 5-MW floating offshore wind turbine
Просмотров 2,5 тыс.5 лет назад
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...
Direct Numerical Simulation of a wing profile
Просмотров 9 тыс.5 лет назад
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 Physic...
Flow past a cylinder at Re=3900 with immersed boundary conditions
Просмотров 6 тыс.5 лет назад
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...
Aerodynamic investigation of a helicopter rotor hovering in the vicinity of a building
Просмотров 2,6 тыс.5 лет назад
3D URANS computation with elsA solver ( elsa.onera.fr ). The building is modelled by IBC (immersed boundary conditions) in the simulation. Part of Garteur AG22 project ( 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, U...
Hovering rotor in ground effect interacting with a square yard
Просмотров 6 тыс.6 лет назад
Hovering rotor in ground effect interacting with a square yard
CFD computation of helicopter fuselage and soft rotor
Просмотров 11 тыс.7 лет назад
CFD computation of helicopter fuselage and soft rotor
CFD computation of helicopter blade dynamic stall
Просмотров 11 тыс.8 лет назад
CFD computation of helicopter blade dynamic stall
What software did you use for the simulation? it is great
Sorry, I think the tail rotor turn on other side.
O sentido do expiração está errado para o passo direito
This gives fractal zooms a serious run for their money.
what is the forward slat for
Extending chord length
good simulation. better if you add the procedure on how to do it.
its great really
why 4 vortices? why not 1 or 2 of them? please help
Is there models to calculate the lift forces acting on the blade. Do manufacturers of helicopters have to do these CFD simulations in order to caculate these things? If that's the case how did they develop earlier helicopters?
Hi, yes there are simpler models to get the lift and drag forces for this configuration for instance based on lifting line and vortex wake models. But CFD can provide much more accurate information on boundary layer and vortices interactions. Besides, it can provide data for acoustic propagation.
@@oneracfd8725 Thank you so much for uploading these stuff.
Can you explain what this is
Hi, this is a classical test case for CFD numerical schemes. See for instance : en.wikipedia.org/wiki/Taylor%E2%80%93Green_vortex
Why is this in my recommendations?
because you are an NPC who thinks google is your mama, spoonfeeding you only your kinks. choose ofans. :)
Is it possible to share the amount of ram required for the method and 1Bn element.
may I ask, what is the variable you are showing?
Hi, the first part shows isolines of Q-criterion and the second part shows an isosurface of Q-criterion colored by vorticity magnitude.
Thanks. Lag time is Bad.
please tell us the software name
Hi, Navier-Stokes solver is onera code fast ( fast.onera.fr) and post/pre/viz is done with Cassiopee (cassiopee.onera.fr).
Can I just ask why does it sound like you have Titanic singing in the background?
looks cool, no idea why 0 comments tho
Stunning! thank you for posting this video! More please!
Impressive in such a level that can not be described in words
Hi Great, How can we simulate this figure in Ansys fluent? If you have any ideas, could you share them with me? tnx. Also How do you put its oscillating movement?
Hi Great, How can we simulate this figure in Ansys fluent? If you have any ideas, could you share them with me? tnx. Also How do you put its oscillating movement?
Sir please provide the full tutorial
This is fuckin beautiful
Why is there high pressure at the trailing edges of the wings and tail/ rudder ?
Because the trailing edge has some non-zero angle, and two streams (above and below the wing, or from left and right side of the rudder) are colliding with each other. Google "cfd 2d airfoil pressure" and in images you can find similar effect for low angle of attack.
Que coisa maravilhosa
What is a heat flux streak?
Dose compression of airflow calculated very rapidly and short-timing?
Basicly, here in Europe, maple syrup is not as easy to encounter as in North America. We have good honey, dont get me wrong, but its not the same as when I used to go to aunt Marcela's place to enjoy a nice apple pie. Keep up the good comments!
WOW !!!
Soooo beautiful
hâte de le voir voler ^^
I saw blade has conctant flap angle in simulation. I wonder flapping motion is included in simulation or not. I mean Helicopter blade rotates flapping motion and it has different angle with respect to azimuth angle.
Hello, blade flapping, lead-lag and pitch variation during rotation are taken into account in this simulation.
That leading blade vs trailing blade lift differential was a big deal in the two blade AH-1 Cobra.
perfect, how can i obtain the CAD model of this aircraft?
RC helicopter model RC pilots have processed 80% of your problems in quite a few years. So I don't see what we have to admire?
I'm not sure what I see around 0:21 - 0:32 🤣🤣🤣
What do you mean?
Use les ? Urans ? Or dns ? Thats amazing
It appears LES
Hello, in this simulation RANS model (Spalart Almaras) is used near the blades and LES in the remaining part of the computational domain.
Given the amount of work that went into building this model, it would be very interesting to learn more about what specific goal it was built for. Was it the demonstration of sliding meshes, demonstration of software capabilities, or a specific physical aspect? I assume that this is just a prescribed motion of the blades, and not coupled with structural mechanics to analyze forces on the blades, fluid structure interaction, or lift forces. Even as a pure CFD model, this is very powerful in showing the interaction of complex blade motion with the air in the domain. There is of course always the question what software was used to build and run this model, how stable it is, and so on. This represents a ton of work. Excellent video.
this represents a ton of computing time rather
Wich size of RAM did you use?
The simulations and the visualization with your software is really amazing. Much kudos! I wrote similar CFD software, have a look at my RUclips channel :)
If you add some explanation at the start instead of in the description, I think this video could really take off... :D As someone with a tiny bit of science background, iso surface is something I can manage, but Q criteria and vorticity magnitude are alien to me. Anyway, I'm glad the algorithm sent me here. It was nice to watch blade angle of attack change and to see the whole thing.
Hello, thanks for the comment. We'll try to take it into account for our next videos.
We paint the air not ur wall the next level ^,^....
the sheer amount of computation necessary just to perform one rotation
Exactly lol..first thing that came to mind just from seeing the thumbail
Hello, CFD (computational Fluid Dynamics) requires an accurate mesh for solving the equations of fluid motion. For accurately solving the boundary layer, the first cell on blade wall must have a height of 2 mm for this simulation. For accurately solving the wake and main blade vortex, cells of length 2 cm must be used. This leads to a mesh of 4.1 billion cells representing about 2000Gb of data. Thats why we need to perform the simulation in parallel on HPC clusters. But it enables to predict unsteady loads, transcient phenomena that deteriorate the rotor performance and radiated noise (tonal and broadband to some extent).
Would it differ in "Other" atmospheres than our Earth ??
What program is this? Ty
CFD
@@aileronhelicopters “Where’d you get that cheeseburger?” “Fast food”
What software
@@Resch72113 that actually made me spit my drink out 😂
@@Resch72113me die 😂😂😂😂
impressive
Étonnant on dirai qu’il ce crée un vide D airs ça devrai imploser genre cavitation
Dear, could you please share a complete video of this simulation with me
Magnifique modélisation. Dommage que la variation de l'incidence n'apparaisse pas.
Je partage la remarque. La vidéo perd tout son intérêt C’est dommage
@@erickflightair8714 Comment ça "la vidéo perd tout son intérêt" ?
@@professionalprocrastinator8103 la variation (augmentation) de l'angle : corde de profil/direction du vent relatif n'est pas présentée. Hors la perte de portance d'un profil ne peut se faire qu'avec cette variation qui va entrainer une diminution de la couche limite avant le décrochage. Rien de tout cela n'est montrée dans cette vidéo. Frédéric le fait aussi remarquer. Un néophyte ne comprendra donc rien à ces images sans un commentaire accompagnateur. Bref cette vidéo s'adresse à un public averti. Voilà pourquoi je dis que cette vidéo n'a aucun intérêt pédagogique en l'état.
L'incidence du profil est l'angle alpha, affiché en haut à gauche dans la vidéo.
@@oneracfd8725 En effet, je n'y avais pas porté attention. Merci pour la précision.
cool simulation :) - what is the title and author of soundtrack?