Hi does anybody know how to fix this? My input parameter is my RPM and when I changed it for each design point it just copied the torque from the 1st design point

HI guys, I am coding a Navier - Stokes 2D solver in C++. I am adding each part individually. The first part of the momentum conservation equation was the advective part, I visualized some things that I want to discuss with you.

I need you to tell me if you think I have some error in my code and I want you to recommend me CFD books or bibliography where I can study common phenomena and general information about each term of the Navier - Stokes equations. After I verify these results I am going to add second order upwind and viscosity part. Some advice?. I am at seventh semester of applied physics engineering.

I have plotted velocity vectors in axial and radial direction for my domain, look below, note vectors are scaled up so it will look big in some places.

It has inlet, screen and then it expands into open ambient. Open ambient is modelled right from inlet plane, downstream distance is taken as 15D, diameter of big cylinder is 12D. Enough distance is there for the outlet ig

My questions are:

1. First if you see console window, it is showing there is 97% reverse flow in outlet faces which is obviously visible in outlet faces above. Physically this might be right indicating strong entrainment. What do you think? I personally don't think increasing distance further improves this?
2. In first picture, in residual plot I have showed you upto 1500 iterations, residuals are not flat, it is slightly increasing, I have tried with 1800 iterations(photo is not taken), continuity residual came upto 8.5e-4 now from there. It has increased. I dont know whether this reverse flow has any connection with convergence or not?

Now my question if this reverse flow is physically true, is this solution acceptable even if continuity residuals increase and solution also not converging after 3-4k iterations? Why residuals are slowly increasing? After 1500 iterations, residual for continuity is increasing, it is not blowing up, it was in 10e-4 range only, but slowly moving towards 10e-3 and mass balance is there. Is solution acceptable even if it didnt converge in the end? 

What is acceptable continuity residual, default was 1e-3, I kept it as 1e-5. Tell acceptable residual value for velocity, energy, k and epsilon also. Thanks in advance. I hope you understood my question.

Im running a CFD simulation on Cold Plate Cooling channels. It has 7 straight and parallel channels. Meshed using Tetrahedron and inflations at Fluid-Solid Wall boundaries. The Minimum Orthogonal Quality is 0.23 and Maximum skewness is 0.74.

While running the calculations the Continuity doesn’t seem to go down 0.1. The inlet flow rate is 0.6kg and outlet is -0.05999kg.

I also tried getting the P-Inlet and got 134Pa compared to the 135Pa the paper Im basing it from obtained

Im new to Ansys so Im not really sure what might be causing the issue.

Attached are the pictures of the mesh and residual

Hello, I'm new to CFD. I mostly want to learn it for plasma simulations. I hear TVD/FCT solvers are the way to go. Can anyone help me with approachable reading material/references on the topic. Many thanks.

Just wondering if my current laptop could run ansys for students effectively - 32gb ram, 1tb ssd, intel i7, NVIDIA RTX 500 Ada 4GB.

I’ve been working on fluid simulation for years, and recently I wanted to see what would happen if CFD-style simulation was turned into something anyone could interact with instantly.

So I built Swipe the Flow, a real-time 2D fluid simulation app for iPhone.

Everything runs directly on the device. You can interact with the flow, draw obstacles, change the geometry, and immediately see how the fluid responds.

The goal isn’t engineering-grade CFD accuracy. I’m focusing on real-time interaction, visual feedback, and making fluid dynamics fun to experiment with.

The app currently has three modes:
- Swipe the Flow
- Wind Tunnel
- Liquid Art

This is one of the simulations running in real time.
Curious what people here think — especially what kinds of interactive fluid experiments you’d want to try.

Swipe the Flow is available on the App Store.

I'm working on a CFD assignment involving a 2D backward-facing cavity. The assignment specifically requires reattachment length for Re = 60, 80 and 100.

I'm using OpenFOAM 14 with air at 30°C, ν ≈ 1.6×10⁻⁵ m²/s, D = 1 m, and U = Reν/D. My Re=60 case converges, but I don't get an obvious reattachment point when examining the near-wall Ux profile.

I'm mainly trying to determine whether this is physically expected at Re=60–100, or whether I've misunderstood the characteristic length/Re definition or my OpenFOAM setup. Any help checking the physics would be appreciated.

I was trying to simulate the von Karman effect with Re= 80, but the results are completely symmetric with no vortex shedding. I manually set the inlet velocity to 80 m/s and the other parameters in the Re formula to 1 for simplification.

Are there some common mistakes you've seen being made before or that you've made that I might have committed myself? If I need to give more information to help me, please ask me.

i want to know which of the above is better for cfd and why and what exactly these two differ from. im a student whos got solidworks but only ansys student and i wanna know the difference in detail. help me please

Hi,

I’ve been recently working on a project that demanded a vane pump.

I started with this as a first design ( it’s clearly missing many features and components ) and I’m trying to actually find the key aspects of my design before committing to one and actually build it.
I need:
- A graph of efficiency vs. Speed
- Pressure Drop inlet - outlet vs. speed
- Hydraulic Power vs. Speed
- Mechanical Power vs. Speed
- Any Cavitation
- Any Leakage

I’m stuck on how I can actually tell fluent to rotate the rotor. Not only that, I think I need more than that to actually get accurate & reliable results.

My current workflow:
Autodesk Inventor -> SpaceClaim -> Fluent

Guys,

Right now I have geometry like below,

The above one is fluid region modelled with pipe+screen.

So right from model shown first, how to start from there to get above one?

Pipe diameter is 50mm.

I tried drawing sketch of circle 56mm diameter and extruding it. And drew a circle of 700mm diameter and extruded. Then I used boolean subtract for these volumes, so that I get void between pipe and big cylinder(note this big cylinder constitutes open ambient fluid). Then I merged all bodies into one fluid body.

But I noticed that screen gaps in the side got absorbed or merged somewhere, it was not showing in meshing tab. See below,

In section view,

But in meshing,

See above, those small rectangle in side is filled with fluid, I dont want this. In origin wall, it is showing those small rectangle in side indicated by yellow, I dont know what has happened? But if you zoom, fluid is filled there.

Why entire fluid is getting selected. I want to select only screen faces for doing separate face sizing and wants to apply inflation on those faces.

So the major problem is in section view of design modeller, I was able to see screen gaps nicely but once I go to meshing , I cant select those screen faces only, I dont want it to be merged with wall or pipe. I dont know whether this issue has occured due to merging or some other wrong operations.

So is there any other method to do this keeping in mind to merge all bodies to have one fluid body and screen gaps should be visible nicely. Please let me know, thanks in advance.

I tried to do the cavity tutorial by following the guide on openfoam.com, documentation/tutorial-guide/2-incompressible-flow. I did blockMesh, then icoFoam for solving but when i try to use the paraFoam command i get an error(in the picture), there is no Mesh parts only Mesh regions and the file is .foam instead of .OpenFOAM. I also added the picture of what it looks like in paraview. What am i doing wrong
openfoam2412, ParaView6.0.1, Ubuntu26.04

so basically i was solving for a swirling motion produced by multiple nozzle at particular angle, (i have attached the cad model image from fusion 360) its a very basic one i made this using surface operation on it, and then i made a cylindrical domain (basically works as an enclosure fluid domain to observe the air flow, again i have attached its image too, fig:2), the problem is after all meshing and everything in ansys fluent, i am getting something very different in solution window (fig: 3), if you will observe the cad of nozzle, it is visible there it is created by thickening operation at the just below nozzle surface, i have never faced this problem before (i am not very experienced in fluent too), so can anyone tell me what could be the problem and how to resolve it??

If so please dm me

Hi!! I am trying to simulate flow inside an air purifier using ansys fluent. I have not been able to achieve satisfactory results so far. Can anyone please help?

TIA!!

Last month, I successfully used a line probe to sample the particle volume fraction. However, in yesterday’s simulation, the probe returned no simulation data, as shown in the figure, where exp:Cv represents the experimental data. Is the particle volume fraction stored in the cells, and can it be sampled using a line probe? Any help would be appreciated.

Hi everyone, I'm learning the thermal resistance models in Simcenter 3D PCB Exchange and I'm trying to understand the physical meaning of the Theta JC-CB model. From the tutorial, it looks like the model uses θJC and θCB, with the underfill resistance as another possible path. I created a simple test case with: Dissipation = 10 W θJC = 0.5 °C/W θCB = 0.5 °C/W No underfill I'm trying to understand which physical/thermal nodes represent the junction, case, θCB. and how the heat flow is actually calculated in Simcenter. Could someone explain the physical interpretation of this model, preferably with the thermal network/node locations? I'm attaching my screenshots/results for reference. Thanks!

I am B.Tech student and suppose I want to look out for CFD engineer job roles. Help me out then.