[fluent_beginner]

Hello everybody,

i want to install a fan in a closed box. I have tried every settings but i didn't find the right one. The problem is that nothing happens. I just have a velocity because of natural convection. To me my settings seem correct. The fan direction is correct. The faces which are defined as a fan are surrounded by air. I only have enabled "Limit Polynomial Velocity Range" and "Calculate Pressure-Jump from Average Conditions". I defined both the "Min" and "Max Velocity as 3.2326 m/s. The "Pressure Jump" is defined as constant and 0. Everything else is not enabeld.

Where is my mistake?

Thank you and best regards

[Chris D]

If you define a constant pressure jump, then I don't think the min/max velocity that you set is being used. So, since dp = 0, the fan isn't moving any air.

[fluent_beginner]

Thank you Chris for your quick reply!
I'm not sure which settings I have already tried. A better documentation could be useful At first I set the "Pressure Jump" as polynomial with no value. Maybe I should try it again if nobody has any other idea or experience with fans.

[Chris D]

Chapter 7.20 in the fluent 6.3 user guide has a pretty good description on how to setup a fan boundary condition. If you set the pressure jump to a nonzero constant, you should get some flow through the fan.

[Saima]

Hi All,

I am doing NASA rotor 67 profile(2D) in CFX, when i import 2D meshing in CFX it automatically convert in 3D by taking unit width.. I picked section number-6 which is on staking angle 50 deg.

There are three options available for Inlet and outlet boundary conditions:

1. I put inlet: Total temp and Total Pressure
Outlet: static pressure
2. I put inlet: Mass flow rate
Outlet: static pressure and static temp
3. I put inlet: Total temp and Total Pressure
Outlet: Mass flow rate

I choose 1 with total pressure and tem at inlet and static pressure outlet.
I fixed whole domain stationary and select my blade rotating with speed 16046 RPM.If i take domain rotation it doesn't run and gave error right away.

I chose periodic conditions but periodicity translation because if i took rotational it doesn't run and gave error right away.

As i told u CFX automatically covert 2D air foil in 3D but with small thicknes. So i took top and bottom as Hub and shroud but with symmetry boundry conditions. I tried Wall but i was not run.

I choose Material :Air ideal Gas.
Heat Transfer Model : Total Energy
Turbulance Model: SST

It runs. But result are not reasonable as i am not getting any temperature difference.

T01= 288 K
P01 = 101352.0 Pa

I am getting
T02: 288.17 K
P02 = 110235.20 Pa

But i havent got good result. All the time my inlet and outlet total temperature is same in all three cases. Why is that?

I solved CFX and Fluent tutorial for 3D blade my conditions are almost same.Kindly suggest me what shud i do.

Thank you and Regards,

[Chris D]

You should start your own thread.

[jasonliu]

[jasonliu]

as u can c, there is a reasonable result if U have correct configuration