Numerical Simulation On Some Phenomena Of The Badbehaved Flow In The Pelton Turbine

The high head hydraulic resource is very rich in the west of our country. Themost significant characteristic of pelton turbine is that it fits high head hydraulicresource well. So pelton turbine is one of the essential turbine in developing highhead hydraulic resource. But compared with the technology on designing teactionturbine，the technology on pelton turbine is just on the way. The flow in peltonturbine is more complicated than that in reaction turbine. When researching thegas-liquid two-phase flow in the pelton turbine, not only the interaction betweenwater and air but also the interaction between water and pelton in the turbine shouldbe considered. The interaction may cause some bad-behaved flow in the peltonturbine, and it can influence the power output and efficiency of the turbine. So it isvery important to do something on researching the flow in pelton turbine.To research the bad-behaved flow in pelton turbine, CFD Numerical Simulationfor a pelton turbine has been conducted using VOF two-phase model.and the maincontent of this article is as follows.(1) Do CFD numerical simulation for the water-leading part of pelton turbine.Analysis the bad-behaved flow and flow loss in the distributing pipe, and donumerical simulation to the flow in nozzle to get the relationship betweenthe needle stroke and massflow.(2) Do CFD numerical simulation for the gas-liquid two-phase flow in thepelton turbine. Analysis the flow in one pelton of different moment. Andanalysis the flow in different peltons of the same moment.(3) According to the gas-liquid two-phase flow analysis in the pelton turbine,Three kinds of bad-behaved flows in this pelton turbine were found. Thenthe reasons that cause the bad-behaved flows can be found. And someadvices to avoid them were given.According to the results, some conclusions can be found. The sudden turn inthe distributing pipe is the mainly reason which cause the bad-behaved flow in it.The vast majority loss in the distributing pipe generates when water flows out. Thereare totally three kinds of bad-behaved flows in this pelton turbine. And they can beavoid by redesigning the pipe and the runner.