Numerical Research Of Influence Of Real Operating Condition Factors Onreduction Of Tip Leakage Flow By Spontaneous Tip Injection

Turbomachinery is a kind of important power machinery which is used to realize energy conversion between the fluid and the shaft power. A gas machine is one of the representative of turbomachinery, and its’ core component is the gas turbine(GT). The existence of the GT rotor tip clearance will not only result in working medium leakage, which leads to power loss, but also have an important impact on the flow and heat transfer characteristics in cascade passage, and leads to additional flow loss. In this study, we take the low-speed linear cascade as research object. Analysis and discussion on the tip leakage and its’ control are made. In addition, the impact of several real factors on the suppression of the spontaneous tip injection(STI) to the leakage is studied systematically, which is theoretically and practically significant.In this study, the numerical model of single-hole spontaneous tip injection was established firstly and the grid independence check and numerical model validation were done. Then through a large number of examples calculation, the effect of endwall motion and blade rotation on the cascade flow characteristics, the leakage flow, the blade circumferential load and the turbine entropy efficiency were studied. Afterwards, by using the method of three-dimensional numerical simulation, the influence of the cascade inlet temperature on the cascade flow and heat transfer characteristics, the leakage flow, the blade circumferential load and the turbine entropy efficiency were also studied. Finally, how those real factors could influence the suppression of STI on the leakage flow were concluded, which provided a theoretical basis and technical support for this passive control method being further applied and which laid a foundation for improving the turbine efficiency, ameliorating the cascade working environment in the future.