This document discusses fluid dynamics and agitation. It defines the difference between agitation and mixing, and describes the purposes of agitation such as suspending solids, blending liquids, and enhancing heat and mass transfer. It also discusses agitator vessel design including the vessel, baffles, impellers and motor. Different types of impellers like axial and radial flow impellers are described. Factors affecting agitator design and applications of agitation in industries are summarized.