Based on the continuity equation and the motion equation of fluid dynamics, a mathematical model of high pressure transients in water hydraulic pipeline is presented. In the model, the friction item is consist of steady friction item and dynamic friction item, using the Darcy-Weisbach equation to solve steady viscous friction item and using four exponential terms instead of weighting function to solve dynamic friction item. By finite difference method accompanied with Matlab/Simulink, an example of high pressure turbulent flow in water hydraulic pipeline is configured so as to simulate the dynamic characteristics of pressure transients. The comparison between the observed result and the simulation result shows the mathematical model of high pressure transients in water hydraulic pipeline with turbulent flow is reasonable.

A newly constrained multi-objective differential evolution optimization technique (CMODE) for security constrained economic/environmental dispatch (EED) was proposed. The proposed CMODE evolved a constrained multi-objective version of differential evolution (DE) by employing the traditional multi-objective differential evolution (DEMO) and constrain handle technique to balance the search between feasible region and infeasible region. The proposed CMODE method had been applied to solve the security constrained EED problem. Experiments had been carried on a standard test system. The results demonstrate the high efficiency of the proposed method to solve security constrained EED problem, and the necessary of taking security constrains into consideration.