Kovasznay flow corresponds to an exact solution of the NavierâÂÂStokes equations and are interpreted to describe the flow behind a two-dimensional grid. The flow is named after Leslie Stephen George Kovasznay, who discovered this solution in 1948. The solution is often used to validate numerical codes solving two-dimensional Navier-Stokes equations.
Let be the free stream velocity and let be the spacing between a two-dimensional grid. The velocity field of the Kovaszany flow, expressed in the Cartesian coordinate system is given by
where is the root of the equation in which represents the Reynolds number of the flow. The root that describes the flow behind the two-dimensional grid is found to be
The corresponding vorticity field and the stream function are given by
Similar exact solutions, extending Kovasznay's, has been noted by Lin and Tobak and C. Y. Wang.