Gradient of species mass fraction
I found from the manual of FLUENT at UDF manual 5.3. It says that in order to retain the gradient data, you can prevent the solver from freeing up memory by issuing the text command "solve/set/expert" and then answering yes to the question "Keep temporary solver memory from being freed?". However, I set this anwser as "NO" and calculated the gradient of one UDS by "C_UDSI_G" macros. The gradient value is reasonable. Do you know why i don't set this text command to keep the memory, but i got reasonable gradient data. However, no matter what i answer this command "YES" or "NO", i can not get the correct gradient about species mass fraction by C_YI_G or C_YI_RG? Thanks.