Pi Brain vs iTurbo

How many digits of pi can you remember? Since pi is an irrational number, the digits never end or repeat. You will probably never have to use more than a dozen digits in any calculation, so why learn the digits of pi? For some people this is a challenge. The Guinness record for remembered digits is 67,890 digits. With this program you will have the opportunity to test your memory, and learn a universal number. Have contests with your friends and family. This is a great learning tool for all ages. You be surprised how much you can remember with a little practice. The option to save the score will only appear if you do not make more than one mistake and do not use the hint or switch to the learn mode. Scores can be sorted by date, name, or score. Use this list to verify your retention over long periods.

This application performs a Direct Numerical Simulation (DNS) where the Navier-Stokes equations are solved for two dimensional incompressible homogeneous turbulence. These equations are a set of nonlinear partial differential equations. The time stepping is performed with a simple Euler method where the time step is calculated so that the CFL number does not exceeds the given number (should be less than 0.8 otherwise the simulation blows up). The equations are solved in the Fourier space where the calculation of the nonlinear term transforms to a simple multiplication. The main CPU usage is consumed by transforming the vorticity field back and fourth between the Normal space where the time-stepping is performed and the Fourier space where the nonlinear term is calculated.