defining regions

Harriet Pearson

hi, i wondered if someone could help me. I am trying to simulate a HGV in the wind tunnel, and have been told to make the meshing surrounding the model dense and everywhere else not so compact. The problem is that my object automatically creates regions where i dont want them and i cant create them away from the edge of my HGV. Could someone please let me know if it is possible to delete regions made when object is made and also is it posible to create them where ever you like in the wind tunnel.