Learning Forum

[marwan abdelhamid]

hello everyone i am working on a project for a natural ventilation in a 2d room as in the picture, the probem is that whe i tery toget the mass gettin in an out of the room it's not equl to zero, i am doing this in post prcessing using line with its coordinates for x and y from design modular, can anyone tell why this is

 happening , iam alculating the mass using surface integral then choosing mass flow rate.

[Rob]

You may want to check the mesh in the doorways. It's not great as you've only got one cell on the wall thickness and it's then likely going to effect accuracy. Have a look at thin walls in Fluent. 

Re the imbalance, how is your convergence, and how much of a difference are you seeing?