I posted a discussion before a week ago and found no useful answer
My problem is i am simulating a fluid in a very small channels and Initial automatic mesh cells is too big for this small Chanel even when i use 8

i removed the mark from automatic settings and and make the number of cells per plan 1000 which is max now the results close to the exact solution i have from Navir Stocks equation with the same assumption but there still an error.
My question is
Is there any way to reduce the size of mesh cells further by controlling the cells size ? i see i can control only number of cells am i wrong ? is there any way ?