some time during running fluent i m getting error named

Error: divergence detected in AMG solver: x-momentum Error Object: ()

can u tell me why it is coming or how to rectify it.

Based on what you provided? No...

Search the forum. You'll see divergence has many causes. 95% of the time it's your setup or your mesh. 5% of the time you have to do something special during the solution process (like ramp up from a slower velocity).

Search the forum and try the solutions you find there. If you still can't find an answer then post more info on your problem.

Best of luck. Jason

In my experience divergence is caused due to several issues such as grid, and unphysical initialization of the problem in hand. With limited information I will try to possibly give you the information of how I eliminate divergence in most of the cases:

For instance have your URFS tightened that helps sometimes, If you are using UDFs make sure you have allocated all the UDMI properly otherwise you can land up with segmentation violation, Specification of gravity should be paid exteme caution, Add models one by one to your case set up for instance if you are using E-E model then add interphase forces one by one, Check your boundary conditions: Many a times boundary conditons are a major contributor to divergence, if you are performing unsteady calcualtions then try with smaller step size for the first few iterations then switch to coarser time steps, use MUSCL scheme sometime it helps. I gahter this might be helpful.KP