abstract:In fluid mechanics, Kelvin's circulation theorem (named after the Irish scientist who published this theorem in 1869Katz, Potkin: Low-Speed Aerodynamics) states In an inviscid, barotropic flow with conservative body forces, the circulation around a closed curve (which encloses the same fluid elements) moving with the fluid remains constant with time.Kundu, P and Cohen, I: Fluid Mechanics, page 130.