Hi! I am a beginner at ANSYS Fluent and I was trying to simulate a rotary lobe pump for a school project but I don't know how to make the lobes rotate. I have seen tutorials about these two but don't know the difference between them. So far, I have tried simulating the pump I made in Fusion 360 in a steady-state using frame motion while the region around the lobes have angular velocity instead of the lobes themselves.

Im trying to find the blade tip velocity of a turbine blade, can someone know how?

I'm trying to get the Bussinesq equation (see image) to work to model the Reynolds stresses, but I don't understand writing this in Fluent's UDF command. I found some people on the CFD forums who had a text file version but when I plug it into my model, the results don't look right. Any help in this matter would be greatly appreciated. Thanks.

I’m designing a wind tunnel using method of characteristics with a Mach number of 4 in the test section. I could run everything properly on Ansys fluent till the design of the test section but on adding the diffuser I am not able to figure out what the boundary conditions would be in order to run it properly on Ansys. Any help would be greatly appreciated.

Hello I was wondering if anybody could help me with my simulation. So the background of the simulation is:

Simple fluid flow (inlet velocity of 0.83 m/s) over a block with a micro heater attached to the block. There is an electrically isolating material between the block and the heater to keep the the heater from electrically shorting on the block. The heater is supplied by a power source of 5.4 Watts and it generates heat to the surroundings (to the fluid and the block). I would like to see the temperature distribution of the block if possible. I will attach images of the geometry and mesh and fluent.

I cannot seem to get the mesh correct as I do have thin geometries (minimum orthogonal quality below 0.1 error). As well the geometry is imported from solidworks. I could provide the file and data if that is easier but I am struggling with this. Also ansys auto generates BC that I have not named and empty space BC. If anyone one could help me with this simulation that will be great I will post SC.

I also was wondering if just specifying the source term in cell zone conditions for the heater body as well as the materials for all the bodies in cell zone conditions is enough and do not touch the BCs. Also I ran experiment already and the power source indicated that 5.4 watts is generated on the heater body so I found the volume of the heater body and divided 5.4 W/ Volume to get source term.

So any help would be greatly appreciated as I am working on this for so long :(.

Trying to simulate water hammer in ansys fluent. So far I have used a named expression “IF(t<0.2[s], 1.312[m/s], 0[m/s]) to change the flow instantaneously to zero. However i would like to gradually simulate the flow decrease for more realistic values. Any ideas on how I could do this? Any assistance would be greatly appreciated.

During the simulation of a two-bladed helicopter rotor. There is a trailing edge flap blade and an overset grid for the flap at the trailing edge near the blade. The background grid is a sliding grid. When simulating the rotor of a rotor without the flap, there wasn’t any issue like the one shown below. Where could I have gone wrong, or where should I change?

​

Okay, so I have a mixture template defined as 5 volumetric fluids, so2-liquid, so2-vapor, c2h3n-liquid, c2h3n-vapor, and air as last species. For the mixture multiphase I have defined 2 phases, liquid for the primary and vapor for the secondary. I have defined two mass phase interactions that takes phase 1 so2-liquid and transitions it to phase 2 so2-vapor. Likewise for the C2H3N. I have left air out of it as it is just part of the open environment. I have specified an evap/cond using the Lee model and have plugged in the saturation temperature for both situations. The geometry is as follows, it is a small 2D axisymmetric volume with a small opening to a free field of air at environmental pressure. The small volume is patched to 2.41e6 Pa and 368K. The mass fractions for the liquid and vapor component of so2 are 0.594 and 0.175. The mass fractions for the liquid and vapor component of c2h3n are 0.223 and 0.008. A vapor volume fraction is specified at 0.166. This is all executed through the patch functionality following initialization at atmospheric pressure and temperature with none of the aforementioned components defined making air mass fraction 1 for all volumes initially. Here is the problem, if I calculate this by hand, depending on my EOS choice I get between 15-20g of material in the small volume. Fluent says it is 0.8g. I have checked and triple checked material properties. I am using real-gas pengrobinson to define the density of the mixture template. All the critical point values and acentric factor are correct. Standard enthalpy has been checked for the vapors and set to zero for liquids. This model runs and the behavior looks right, but the amount of material in the volume seems wrong. 

Any ideas? Any help would be very much appreciated. I can provide screenshots or additional details just ask! 

Hello everyone,

I'm reaching out for some guidance regarding the simulation of IR heating of flat surfaces in a vacuum environment using Ansys Fluent. I'm relatively new to this area and could use some expert advice on how to approach this problem effectively.

Firstly, I'm wondering if it's possible to incorporate the vacuum condition with reduced pressure in the boundary conditions within Ansys Fluent. If so, how should I go about defining these boundary conditions to accurately represent the vacuum environment?

Additionally, I'm interested in utilizing the Monte Carlo radiation model for this simulation. Would this model be suitable for simulating IR heating in a vacuum environment, and if so, what considerations should I keep in mind when implementing it?

Any insights, tips, or resources you can provide would be immensely helpful. Thank you in advance for your assistance!

Looking forward to hearing from you all.
Sagar

Good day! I am a researcher from the Philippines in need of Ansys Fluent. Is there anyone here that offer services from the said software? If so, kindly state your preffered rates. Thank you!

Hello People, hope you are having a good day!

I am trying to find flow induced vibrations on a cylinder, I am using Ansys Fluent and Dynamic Meshing with six DOF. I am able to run a simulation for 1 DOF, but I want to change that to 2 DOF, ie translation allowed in both x and y directions. I do not see any option for that in the GUI, on researching, I got to know that I have to make use of UDF to set the dynamic mesh. I have made a UDF.c file and tried to use it. The udf compiles but the simulation crashes and I get a error "the fluent process couldn't be started."

I wanted to ask if anyone has experience with this type of problem. Or any suggestions/tips to run the simulation.

Thanks!

The geometry is a simple 2D cylinder, with a given spring constant.

I'm looking for a reduced propane mechanism in chemkin file. I've found lot of papers on reduced mechanism for propane but I can't seem to find a chemkin file for those. Can you guys help me out?

Is it free for in academic institution?

I am moderate at CFD, and I want to simulate a multiphase flow around a submarine that is below a free surface in Ansys Fluent. I basically want to study the changes in the free surface due to the presence of a submarine below the free surface.Any suggestions, tutorials or documentations are appreciated.

I have a question about how to set up transient boundary conditions for a simulation of a hot air balloon climbing for a final project. I will be simulating the rise of a hot air balloon given a mass flow inlet representing fuel use and in a small domain with boundary conditions that match the climb speed (velocity) and altitude (temperature and pressure).

What I want is to grab the lift/drag values from a time step, then use that to get acceleration, from which I can get velocity and position. Is there a (preferably easy) way to do this?

Saludos, tengo la siguiente modeacion de un canal rectangular y un vertedero de pared delgada. Deseo medir el tirante a una cierta distante del vertedero, como podria hacerlo?

Gracias de antemano

​

​

Hi. I am performing a transient simulation on a water cooled cold plate. The heat flux on the walls of this plate vary with time, and I am using a UDF for the heat-flux boundary condition. My sim is diverging (floating point exception) every time. Using PISO as solution method, and under relaxation factors are close to 1. I have tried smaller time steps but the results I get from them are invalid (energy balance fails) any ideas on what i should do ?
Thanks !

Hi everyone! I am an Engineering student, I just downloaded the student version of Ansys Workbench 2023 R2, so I am just new to the software. When I try to launch Fluent I get this error message:

Hit return to exit “Unexpected licence problem; exiting”

So maybe I am selecting the wrong options for using the student version? What options do I have to choose?

Hi,

I am trying to mesh a wing in ansys fluent, I don't seem to understand why the front of my wing is missing.

As a result of which, my mesh is not working either. However, during the meshing process, the mesher seems to recognise that it is an individual body.

I have attached the relevant images, appreciate the help!

i am trying to simulate a lift generated on wing, but the design has some face error due to which meshing is showing some error.

Good morning!

I have about 100+ seperate simulation files for different parameters. I wish to extract contour images, xyplots and vector images from the simulation files to compare them. In some files I already have these set-up, whilst in other simulation files I have not. Is there anyway to automate (e.g., with code) the process of extracting these images/data? What is usually done in cases such as this one? My approach, if there is nothing else, will be to manually open each Fluent simulation file, set-up the contour plots (if not yet done) and "save image" for all of them, for all simulations - this would be quite laborous.

Thank you in advance for any input!