ABSTRACT
This chapter delves more deeply into the kinematics and properties of fluid flows. Laplace's equation has the same mathematical structure as the gravitational potential in a vacuum, which means that one can easily adapt (numerical) methods for computing gravitational fields to incompressible fluid problems and vice versa. The De Laval nozzle provides an insightful example of the behaviour of fluid flow in a scenario of converging and diverging streamlines. Flow lines can be a powerful tool to gain direct insight into the physical implications of fluid flow patterns. For steady flow the difference between streaklines, parcel paths and streamlines dissappears. The chapter explores the behaviour of fluid parcels along streamlines by considering the vorticity of a fluid flow. Bernoulli's equation is an insightful conservation law that holds along a streamline under certain conditions. Potential flow that is also barotropic obeys a strong form of Bernoulli's equation.
