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Computational Fluid Dynamics (CFD)
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/r/CFD
Figure 1: Overal image showing Figure 2 and Figure 3
Figure 3: Heights in the middle of a vertical split edge.
I tried to straigthen all of their length using "Edge Params" and copied them "To All Parallel Edges". It worked well but as I travel horizontally it, the heights vary and then decrease, then increase again at the very end (I don't put the image here but I think you get the idea). Later on I tried to split the vertical edges and "Edge Params" them all again and the heights turned out to decrease much faster and at the middle of a split edge it looks like a pyramid (Figure 3)
I am trying to simulate the static and dynamic part in ansys fluent , simulation but currently facing a lot of error , please is there is anybody willing to provide me a certain guidance in this matter , would be very helpful
Is there a way to use flamelet generated manifold with non-premixed combustion? It only becomes available if I select partially premixed combustion
I was wondering if anyone knows of chemkin mechanisms available for ionization reactions due to extreme heat for oxygen & hydrogen species (Ex: formation of H+, OH-, H3O, etc.). I've been looking online for a while, but am having difficulty finding any.
Any help is greatly appreciated, even if it's just pointing me in the right direction for making my own mechanism and how I'd calculate the necessary values.
Thanks!
It might be stupid question but I could figure it out. I have created a mesh using blockMesh, now I want to refine some regions near the wall using snappyHexMesh, in geometry section what should I put since I don't have .stl file. I have tried to keep it empty, snappy runs but I doesn't refine the mesh. If I tried to add the names of the boundaries it doesn't run. I tried to mesh it in pointwise but for some reason openfoam give me high residential and terminate the run (even though i ran the same geometry that i createdusing block mesh). Any suggestions?
I ran 2 different sims. Every setting is copy-paste the same. The only difference between the vessels, is the fact that the one has cargo (containers) on top, while the ohter doesnt. Why on earth does the no cargo sim, gives bigger wind resistance results? 🤔
First three images are of bullet like shape.
Last three images are of airfoil like shape.
{in air foil like shape , we can see both Boundary layer separation and reverse flow (vortex) but not in bullet} Thus interpretation inside curly bracket might be wrong.
and can you guys help me validate how Cd ration between the bodies hold for the drag force.
Hello everyone, I am looking for advice regarding geometry preparation for simulating a turbine blade with very small cooling holes (diameter is 0.5mm). The CAD Geometry I am using has sharp edges for the cooling holes. I am wondering if I should leave the geometry as it is or if I should add small fillets (0,05mm) to prevent singularities? Are such small fillets an improvement?
Hi!
For the final exam, I have to find a Nusselt correlation as a function of the Richardson number for a descending turbulent flow in a mixed convection regime inside a vertical pipe, using numerical tests on STAR ccm+ and compare it with correlations available in the literature.
Currently, I am stuck because I can't find anything in the literature and I've searched all possible papers that my university has access to, do you have any suggestions?
Are there any courses or books online that discuss post processing in detail in terms of not only how to do it in a solver, but also how to present it to teammates or effectively communicate results as part of a larger project? I am interested in doing the "soft" skill side of this better.
Hey, i have a Simulation on Star ccm+ and have a problem with Reversed flow. I heard there is an option to set the Outlet artificially backwards but i found nothing how it works. Picture of the Geometry in the comments.
Has anyone used Ansys fluent gpu solver. I have seen promotional posts by Ansys promising simulation speed up by 40x.
What is the speed up like, is it robust. Can you share your experience.
Dear Experts.,
1.How can I configure the relevant parameters in Pointwise to reduce the number of non-orthogonal and pyramidal cells in the volume grid?
2.While generating a volume grid in Pointwise, I noticed that some domains at the connection between the trailing edge of the wing and the fuselage are automatically triangulated. How can I adjust the settings to minimize this issue?
Thank you in advance for your help!
I wanted to find the height of the boundary layer on my airfoil (Eppler 216) for AoA = 10.5 and Reynold's Number = 20000
So I tried to export the BL data from the xflr5 software. I got a text file which had various terms and parameters that were varying along x in the top and bottom side.
can someone please help me in understanding what each of the terms mean? I would be grateful if you could list the sources where I can find info regarding these.
I want to simulate this MOSFET in ansys or solidworks, using this pdf https://fscdn.rohm.com/en/products/databook/applinote/common/how_to_use_the_rth_and_thermal_characteristics_parameters_an-e.pdf
my idea is to make 2 cubes one inside another (as a representation of mosfet)
inner one representing junction and outer representing case
i want to use the resistance given to us to accurately represent the effect of heat sink on the junction temp.
the idea is to set thermal resistances as thermal conductivity of material for an inner cube (junction to case resistance)
my lead told me we can get case temp from your simulation( i got confused, how will i simulate it without Junction interaction) and get the junction temp.
(my lead is of electrical department)
so my question is how will you guys approach this while simulating a heat transfer case with mosfets , how will you model an accurate heat generation model of mosfet in FEA or FVM software(with or without)
(this is making no sense, ;-; , please give me some idea i can work on )
For example, If I want to model ethyl alcohol as a gas injected into a combustion chamber, what would happen if you sent the inlet temp to 300k, where ethanol is a liquid. Will it have trouble converging or give a floating point error, create a pressure singularity so that the temp is possible in a gas phase, or something else?
Hey all,
I've seen some really talented people on here and wanted to say we have some really exciting roles for both automated multiphysics adjoint optimization and mesh generation and refinement at Open Orion.
Hello everyone,
I'm trying to simulate the pressure drop along a line in a 2D OpenFOAM simulation. I've successfully simulated this type of case before, but now I need to add a flow restriction in a specific area to better represent real-world conditions.
I'm struggling to find a clear reference or example on how to implement this. Is it possible to add a pressure drop zone in a 2D simulation? If so, what is the correct way to do it? Any guidance or resources would be greatly appreciated!
Thanks in advance!
Good evening! I'm a graduating high school student, and I urgently need assistance with Autodesk CFD for our research data analysis. This isn't covered in our school curriculum, so I'm struggling to understand how it works, and the deadline is fast approaching. If you're able to help, please feel free to reach out. I'm based in the Philippines. Thank you! 🥹
Hello Fellow, Can anyone suggest some good tutorial on 3D overset meshing using Ansys Fluent. Actually i am trying to simulate the flow through ghe syringe which will fall down on the substrate to make the dispensed fluid line. I want to move the syringe but I dont know how to simulate the motion of the syringe. Can anyone suggest me how to do that or any other information regarding the same. Thank you
Hi all, Aim is to do the external flow and find the Cd and drag force of the car.
I understand that cad cleaning is important for smooth meshing.
Do you have any tips for Cleaning up this Driveaer car geometry using Spaceclaim ?
I have a limit of 1 million cells,
I would appreciate any cleanup tips to avoid error in fluent meshing and also please share any good meshing strategy if any.
Thank you
Hi! I am trying to do a very basic CFD simulation of some Nitrogen flowing threw a rectangular domain. The height is 40 cm and the length of the domain in 10 m and I was told to make the width infinity and to adapt it in Abaqus, but I don't really know how that works. Any ideas?
Has anyone used the default ethanol+air reaction mixture? When I use eddy dissipation or eddy dissipation concept, the temp of the entire domain reaches 4500k or higher, which is significantly higher than that reaction can reach, even in oxygen rich combustion. Any idea what could be causing this? I tried relax to chemical equilibrium as well as direct source. I am trying to simulate ethanol and oxygen combustion in a rocket engine, and was planning to get it working with the default mixture before switching to a more complex mechanism
Does anyone have experience with multi-block HEX mesh generation using Pointwise? I am especially interested in mesh generation for faceted formats like STL, but appreciate if any experienced Pointwise user could point me to a tutorial/guide for the general workflow regardless of the CAD format, since I am not too optimistic in finding one.
I found some tutorials, but still the workflow is not totally clear to me. I do not know what exactly to export from the CAD software to use for mesh generation in Pointwise, and what features exist in Pointwise for this purpose. For example, if I have to create blocks (vertices/edges/surfaces) externally and import in Pointwise together with the 3D model?
My other question is to what extent is Pointwise capable of handling faceted formats in general (not only HEX grids). Is there any treatment you find helpful on the the CAD models externally (like reducing poly count, surface smoothing, skewness quality improvement of the geometry polygons)?
If there is no tutorial available online, I appreciate if anyone could give a workflow for meshing of a simple setup like flow around a sphere, where the sphere is a faceted format.
Hi everyone,
I am working on a centrifugal fan, I have the fan curve. When I match the results with the graph, I get very close values. But I wonder this? When I don't have any information, how can I simulate a fan whose only speed is known? When I define atmospheric pressure on both sides as inlet and outlet conditions, the results are not very realistic? Do you have any advice?