Aerodynamics

Flow past airplane wings and high-speed ground vehicles has captured the attention of fluid dynamicists, applied mathematicians, and computational sci- entists and engineers, not only because of their obvious technological signif- icance, but also because of the opportunity they present to perform elegant mathematical analysis and develop realistic and efficient numerical models. Al- though these flows occur at high Reynolds numbers and often at transonic or supersonic speeds that are comparable to or even exceed the speed of sound, the effect of viscosity is important in two ways. First, viscous stresses deter- mine the drag force exerted on moving surfaces and thus the energy required to sustain the motion. Second, viscous stresses are responsible for the production of vorticity which generates circulation and thereby induces a lift force.