The mixing performance of an experimental device-the enhanced mixing simulator (EMS)-is studied in this paper. In this device, the Couette flow is perturbed laterally, so that uniform and quick mixing can be achieved. Numerical simulation of the mixing in EMS flows is performed, which shows good agreement with the experimental results. Spline interpolation and advanced integration techniques are used in particle tracking, so that accurate results are obtained at low costs. Poincare sections are used to study the long-term mixing behavior. The uniformity of the simulated mixture is evaluated using statistical approaches-the variation coefficient and the Kolmogorov test. The Kolmogorov test is adequately implemented for our purpose and incorporated with efficient sorting algorithms. The mixing rate is determined from the time evolution of uniformity during mixing. It is also shown that although the Lyapunov exponent can identify chaos, it does not measure the mixing rate. Optimal design of the EMS is discussed.