[THA SEANGHAI]

Hello! I am really having a hard time with ANSYS FLUENT, I want to input mass flux of a species on a boundary, then I knew that there is no Boundary condition for species mass flux, so people on the internet told me that I have to write UDF, and now I already wrote UDF for species mass flux, but I do not know which boundary condition should I choose for inputting species mass flux? First, I chose Mass Flux Boundary condition,but the velocities were changed, and the results seem to be wrong, so after that I chose Wall Boundary condition and compile or interprete UDF at Wall BC=> Species=> Mass fraction=> then select UDF that I already interpreted or compiled. Is that the correct way? Finally, I want to compare the values of mass flux that I input and the result of mass flux after calculation, thus how can I compare? I have no idea at all!Thank you in advance!