Metaphoric optical computing of fluid dynamics

We present theoretical and numerical evidence to show that self-defocusing nonlinear optical propagation can be used to compute Euler fluid dynamics and possibly Navier-Stokes fluid dynamics. In particular, the formation of twin vortices and the K\'arm\'an vortex street behind an obstacle, two well-known viscous fluid phenomena, is numerically demonstrated using the nonlinear Schr\"odinger equation.