Analyzing fluid flows via the ergodicity defect
The ergodicity defect -a relatively new approach for analyzing fluid flows- is presented. The method measures the complexity of individual fluid particle trajectories which in turn is used for the identification of Lagrangian coherent structures in the flow. The technique combines ideas from ergodic theory and wavelet theory and is compared and contrasted with other methods for identifying coherent structures. We also consider the theory behind the ergodicity defect and several practical applications of the method.