Help!! Calculate drag force and down force with Fluent

[Kent83]

Hello guys,

Somebody can give me some information about calculate the drag force and downforce with fluent software?

Actually, I'm taking final year project with design aero package for Formula SAE racing car. Now, I already completed mesh my model in gambit but i really don't have idea how to get the drag coefficient and lift coefficient with fluent. Can you guys help me?



Sorry for my broken English and disturbing. Thanks you in million...

[sasquatch]

Which FSAE team are you involved with? Is your gambit mesh 3D or 2D? Have you run the simulation in Fluent already with a converged solution? If so..in the report solution, fluent can calculate the pressure and viscous forces from the your model. Then use your inlet velocity and cross sectional area of the model to calculate the CD.

[Kent83]

Which FSAE team are you involved with? Is your gambit mesh 3D or 2D? Have you run the simulation in Fluent already with a converged solution? If so..in the report solution, fluent can calculate the pressure and viscous forces from the your model. Then use your inlet velocity and cross sectional area of the model to calculate the CD.

Thank you for replying me. It is 3D mesh in gambit and I split my model with half and with a big box. I haven't succeed to run simulation cause I run it around 4 hour still cant get the converged solution. Maybe there have some problem with my setup in fluent. If possible, can you help to to check bout it? Thanks in advance. My step is as follow:

1. Read the grid file
2. Select segregated and implicit solve
3. Define model viscous with Spalart-Allmaras
4. Define Materials constant air density (default setting)
5. Operating condition with default setting
6. Boundary condition : Velocity inlet with 16m/s, 4 symmetry plane (default) and outflow plane(default)
7. Solve solution: Pressure = PERSTO
Momentum = second Order Upwind
Pressure-velocity coupling = SIMPLE
Modified Turbulent viscosity = First Order Upwind
8. Turn on residual Plotting
9. Initialize the solution: Compute from velocity inlet
10. Iterate with 2000

After that, I'm not much know how to continue about it because I still study with the software now. It is this software can help me to find out the coefficient drag and lift after succeed to get the converged solution?

[Guest]

Sounds like the solution method is ok. Do you have a email address so I can contact you.

[weis]

Hi i am a final year student also doing my FYP on race car aerodynamics

i have manage to run Fluent CFD analysis To get the C lift after the analsyis converged you can try
Report > reference value, then paste your frontal area value > compute
the print. However i could not get C drag. Anyway what is the mesh size of your model?my analysis took me more than 4 hours

Which FSAE team are you involved with? Is your gambit mesh 3D or 2D? Have you run the simulation in Fluent already with a converged solution? If so..in the report solution, fluent can calculate the pressure and viscous forces from the your model. Then use your inlet velocity and cross sectional area of the model to calculate the CD.

Thank you for replying me. It is 3D mesh in gambit and I split my model with half and with a big box. I haven't succeed to run simulation cause I run it around 4 hour still cant get the converged solution. Maybe there have some problem with my setup in fluent. If possible, can you help to to check bout it? Thanks in advance. My step is as follow:

1. Read the grid file
2. Select segregated and implicit solve
3. Define model viscous with Spalart-Allmaras
4. Define Materials constant air density (default setting)
5. Operating condition with default setting
6. Boundary condition : Velocity inlet with 16m/s, 4 symmetry plane (default) and outflow plane(default)
7. Solve solution: Pressure = PERSTO
Momentum = second Order Upwind
Pressure-velocity coupling = SIMPLE
Modified Turbulent viscosity = First Order Upwind
8. Turn on residual Plotting
9. Initialize the solution: Compute from velocity inlet
10. Iterate with 2000

After that, I'm not much know how to continue about it because I still study with the software now. It is this software can help me to find out the coefficient drag and lift after succeed to get the converged solution?