Vortex sheet
![Continuous vortex sheet approximation by panel method. Roll-up of a vortex sheet due to an initial sinusoidal perturbation.](/Images/godic/202502/20/Sheet1817223241.png")
A vortex sheet is a term used in fluid mechanics for a surface across which there is a discontinuity in fluid velocity, such as in slippage of one layer of fluid over another. While the tangential components of the flow velocity are discontinuous across the vortex sheet, the normal component of the flow velocity is continuous. The discontinuity in the tangential velocity means that the flow has infinite vorticity on a vortex sheet.