Application of entropy production theory to hydro-turbine hydraulic analysis

The understanding of hydraulic behavior in the hydro turbine requires the detailed study of fluid flow in the turbine. Previous methods of analyzing the numerical simulation results on the fluid machinery are short of intuitiveness on energy dissipation. In this paper, the energy dissipation was analyzed based on the entropy production theory. 3-D steady flow simulations and entropy production calculations of the reduced hydro turbine were carried out. The results indicated that the entropy production theory was suitable for evaluating the performance of the hydro turbine. The energy dissipation in the guide vanes area weighted nearly 25% of the whole flow passage, and mainly happened at the head and tail areas of the vanes. However, more than half the energy dissipation occurred in the runner, mostly at the leading edge of runner blade and the trailing edge of runner blade. Meanwhile, close to 20% of the energy dissipation occurred in the elbow. And it can be concluded that the method of entropy production analysis has the advantages of determining the quantity of energy dissipation and where the dissipation happens.