Axial fansare connected in series in plants to increase the pressure. In theory,connecting two fans in series doubles the pressure increase. The trainerallows the investigation of a two-stage axial fan. A measuring device is usedto determine the pressure and velocity distribution. The trainer includes ameasuring section with two identical axial fans. The carefully designed nozzlecontour and a flow straightener at the air inlet ensure a uniform velocitydistribution with little turbulence in the measuring section. The rotors areequipped with individually adjustable blades to change the angle of attack. Thefans are equipped with outlet guide vane systems. These guide mechanismsredirect the angular momentum of the outflow in the axial direction and allowan increase in pressure. A pipe bend may optionally be installed to rotate theflow at the outlet of the measuring section. One of the fans can be removedfrom the measuring section so that the remaining fan can be studied inindividual operation.