HELP ! MESHING
 

HELLO

i doing meshing in the box.But in that there is a sheet and after subtracting the sheet from box there is problem for meshing. If i made a another virual box inside the box and then mesh then it acept. But i want to know that it is right or wrong. Because in box there is hot water and sheet coming from top-right and coming left-top. So i want temperature distribution on sheet and in water.