mass flow of inlet and outlet is not equal
 

a simulation, the force result looks convergence, but de mass flow of inlet is not the same as the one of outlet. why? how should i deal with the issue?

Is the mass just not converged yet?

looks like you are doing a marine vof case on the wigly hull. you need to be careful when measuring mass flows of water and air in and out of such cases when motion is involved etc. i'd be create a monitor and plot of this to look at the history and when such models are well setup the mass flows do converge but also cycle around zero due to motion and waves. most marine users never do such a report and instead look and convergence of forces, moments and motions.