The Batchelor–Chandrasekhar equation is the evolution equation for the scalar functions, defining the two-point velocity correlation tensor of a homogeneous axisymmetric turbulence, named after George Batchelor and Subrahmanyan Chandrasekhar. They developed the theory of homogeneous axisymmetric turbulence based on Howard P. Robertson's work on isotropic turbulence using an invariant principle. This equation is an extension of Kármán–Howarth equation from isotropic to axisymmetric turbulence.