|
[Sponsors] |
July 8, 2019, 21:11 |
Boundary Conditions for an impeller
|
#1 |
New Member
Join Date: Jul 2019
Posts: 9
Rep Power: 7 |
Hello Everyone
I am carrying out a simulation of a steady simulation of a centrifugal fan. The experimental values I have are : Total Pressure 918.07 N/m2 Static pressure 86.36 N/m2 Velocity Pressure 94.141 N/m2 Flow rate 3.426 kg/s And Shaft power 3.62 kW My boundary conditions are the following Two stator bodies (inlet bellmouth and stationary outlet ) and a rotatory body (impeller) Turbulence model: SST Wall distance Y+ <10 Convergence criteria: 10-5 Number of nodes: 1.3 million Rotor RPM: 1760 My simulation converges properly and velocity and pressure residuals reach below 10^-5 after 400 steps. I tried two inlet and outlet conditions : Operating pressure: 1 atm Condition 1 : Intel condition: Flow rate : 3.426 kg/s and Outlet pressure : 0 atm Condition 2 : Inlet condition : Inlet pressure : 918.07 N/m2 and outlet pressure : 0 atm When I calculate the shaft power from the simulation results the values show more than 50 % error. Calculate shaft power for condition 1 was 1.9 kW and for condition 2 was 0.8 kW. I am not sure why I am getting such low values. My suspect is the boundary condition. Please let me know how to solve it. Thank you Last edited by rj26; July 9, 2019 at 02:01. |
|
August 2, 2019, 09:44 |
|
#2 |
New Member
Eyyup DUMAN
Join Date: Dec 2013
Posts: 1
Rep Power: 0 |
hi ,
Did you try inlet BC :0 pa outlet BC : ...kg /s Mass flow? |
|
August 3, 2019, 03:04 |
|
#3 |
Senior Member
Hamid Zoka
Join Date: Nov 2009
Posts: 293
Rep Power: 19 |
Hi;
- Try total pressure @ inlet and massflow @ outlet. - Check the physics of flow through the impeller. - Compare the calculated velocity levels with those available from experimental values. - Recheck the torque calculation equations. Regards |
|
Tags |
cfd, fan, impeller, mrf. |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
sliding mesh problem in CFX | Saima | CFX | 46 | September 11, 2021 08:38 |
Centrifugal fan | j0hnny | CFX | 13 | October 1, 2019 14:55 |
CGNS Boundary conditions using SU2 | denzell | SU2 | 3 | July 9, 2018 06:58 |
Velocity vector in impeller passage | ngoc_tran_bao | CFX | 24 | May 3, 2016 22:16 |
GETVAR Error in Multiband Monte Carlo Radiation Simulation with Directional Source | silvan | CFX | 3 | June 16, 2014 10:49 |