Circulation may refer to:

Science and technology

Atmospheric circulation Atmospheric circulation is the large-scale movement of Atmosphere of Earth, air and together with ocean circulation is the means by which thermal energy is redistributed on the surface of the Earth. The Earth's atmospheric circulation varies fro ...

, the large-scale movement of air *

Circulation (physics) In physics, circulation is the line integral of a vector field around a closed curve embedded in the field. In fluid dynamics, the field is the fluid velocity field. In electrodynamics, it can be the electric or the magnetic field. In aerodyn ...

, the path integral of the fluid velocity around a closed curve in a fluid flow field *

Circulatory system In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. It includes the cardiovascular system, or vascular system, that consists of the heart ...

, a biological organ system whose primary function is to move substances to and from cells *

Circulation problem The circulation problem and its variants are a generalisation of network flow problems, with the added constraint of a lower bound on edge flows, and with flow conservation also being required for the source and sink (i.e. there are no special nod ...

, a generalization of network flow problems *

Circulation (architecture) In architecture Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and constru ...

, the flow of people through a building *

Circulation (currency) In monetary economics, the currency in circulation in a country is the value of currency or cash (banknotes and coins) that has ever been issued by the country’s monetary authority less the amount that has been removed. More broadly, money in ...

, all currency held by consumers and businesses, but not by financial institutions and governments *

Exhaust gas recirculation In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide () emissions reduction technique used in petrol engine, petrol/gasoline, diesel engines and some hydrogen internal combustion engine vehicle, hydrogen engines. ...

, a nitrogen oxide reduction technique used in most gasoline and diesel engines *

Library circulation Library circulation or library lending comprises the activities around the lending of library books and other material to users of a lending library. A circulation or lending department is one of the key departments of a library. The main public ...

, the activities around the lending of library books and other material to users of a lending library *

Ocean circulation An ocean current is a continuous, directed movement of seawater generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contours, ...

, the large-scale movement of water *

Rhetorical circulation Rhetorical circulation is a concept referring to the ways that texts and discourses move through time and space. The concept seems to have been applied to texts sometime in the mid-1800s, and it is considered, by most scholars, to be either subordin ...

, the ways that texts and discourses move through time and space

Other uses

Print circulation Print circulation is the average number of copies of a publication. The number of copies of a non-periodical publication (such as a book) are usually called print run. Circulation is not always the same as copies sold, often called paid circula ...

, the average number of copies of a publication *

Circulation Festival 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 biol ...

, an annual circus and fire performance festival held in Dunedin, New Zealand * ''Circulation'' (film), a 2008 psychological thriller-fantasy film by Ryan Harper * ''Circulation'' (journal), a journal published by the American Heart Association {{disambig