Axial flow fans are required at many places and hence study of their performance has become essential. The 'DYNAMIC' unit is a ducted axial flow fan having guide vanes on upstream and downstream sides. The unit is having standard aerofoil shaped blades. Both the guide vanes have adjustable angle. The rotoris driven by a variable speed motor and a butterfly valve is also provided to vary the head. Thus the characteristics of fan can be determined at various settings and hence the equipment becomes an important tool for students.