simply model, empty box
 

Hello everybody, I have simply problem..I need to create a empty box with thickness of walls 30 mm, Box have dimensions 0,5 m x 0,5 m x 0,5 m. I do this steps:
1. I create box, with earlier dimensions
2. with tool Thin/surface I set thickness of walls 30 mm
3. then I hide surfaces on side for next step
4. and then with tool "fill" I select interior surfaces of box to fill that volume inside box
, and I have now solid (box), and fluid inside box

Problem is in meshing, because there is no contact between meshes of fluid region and solid part. I do some on changing meshing method and similar, but helpless. I need this model for thermal analysis. I will be very appreciative for any suggestion. and sorry for poor english

King regards