// Workers AI · dad joke modeWhy did circulation go to therapy? It had a lot of fluid emotions.

Circulation may refer to:

Science and technology

• Atmospheric circulation, the large-scale movement of air
• Circulation (physics), the path integral of the fluid velocity around a closed curve in a fluid flow field
• Circulatory system, a biological organ system whose primary function is to move substances to and from cells
• Circulation problem, a generalization of network flow problems
• Exhaust gas recirculation, a nitrogen oxide reduction technique used in most gasoline and diesel engines
• Ocean circulation, the large-scale movement of water

Media

• Circulation (film), a 2008 psychological thriller-fantasy film by Ryan Harper
• Circulation (journal), a journal published by the American Heart Association
• Print circulation, the average number of copies of a periodical publication
• Library circulation, the activities around the lending of library books and other material to users of a lending library

Other uses

• Circulation (architecture), the flow of people through a building
• Circulation (currency), all currency held by consumers and businesses, but not by financial institutions and governments
• Rhetorical circulation, the ways that texts and discourses move through time and space