make a simulation work with 3 physics' in a COMSOL model

a metal body (in the center) is placed in a cube of air. there is a fan that is defined by a velocity field of v_z=-1 m//sec through a cylinder. the model with three physics': heat in solids (for the metal body), heat in fluid (for the air surrounding the body) and laminar flow (of the air). the laminar flow solver doesn't seem to work. You need to define the model properly.