Hi, I want to use y+ adapt but it notes me always : cells to coarsen not to refine and my mesh isn't fine at all !!! it is so illogical to have large cells and the fluent want to coarsen them, perhaps I forgot or I must change something in the allowed min and max, please help.

as i know,

y+ value depends upon the flow behaviour, like velocity, density and viscosity etc,

so first of all calclute a y+ value analatically for your geometry. and give this value in fluent as max.

u can also calculate you y+ by pressing compute button in y+/y*.

for different turbulence model its value differes.

u can also you wall function.

dear read fluent manuall, specially SA model and K-E model and also detail of y+

Thanks!