论文部分内容阅读
The stretching and folding of fluid element during chaotic mixing field isstudied using numerical method. The chaotic mixing process is caused byperiodicsecondary flow in a twisted curved pipe. Using the nonlinear discrete velocity field as thedynamical system, the present study connects the fluid particles stretching along itstrajectory in one period to a linearized time-varying variational equation. After numericalapproximation of the variational equation, fluid stretching is calculated on the whole crosssection. The stretching distribution shows an exponential fluid stretching and folding,which indicates an excellent mixing performance.