|
[Sponsors] |
![]() |
![]() |
#1 |
New Member
Tpozkar
Join Date: Jan 2012
Location: Mexico
Posts: 4
Rep Power: 14 ![]() |
Hello prestigious community of CFD online,
I'm simulating transient combustion using the non-premixed model. When I made the normal calculation (no udf, constant flow rate), both mass and energy balances are low enough to consider their continuity. However, when I use an UDF, which consists in pressure fluctuations at air inlet (flow rate changes with time), the energy imbalance increases. The higher the amplitude of pressure fluctuation at inlet the higher the energy imbalance (there is more heat incoming that going out). I get differences in heat between inlet and outlet up to 7%. Is that a value too high to consider the calculation was wrong. Otherwise, what could be the reason of that imbalance of energy? My mass balance still being low, only energy shows discrepancies. Any help or advice will be highly appreciated. |
|
![]() |
![]() |
![]() |
![]() |
#2 |
Senior Member
Alexander
Join Date: Apr 2013
Posts: 2,363
Rep Power: 34 ![]() ![]() |
Try to decrease timestep
Best regards |
|
![]() |
![]() |
![]() |
Tags |
energy balance, fluent - udf |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Out File does not show Imbalance in % | Mmaragann | CFX | 5 | January 20, 2017 10:20 |
Energy imbalance | seojaho | CFX | 6 | June 21, 2016 20:35 |
UDF to switch on energy equation each time step | galary | FLUENT | 1 | January 5, 2006 19:24 |
UDF to switch on energy equation after X iteration | mat w | FLUENT | 6 | December 5, 2005 07:35 |
UDF for energy source | mauricio sanchez | FLUENT | 0 | August 30, 2005 15:56 |