Abstract
In the large-scale gas or stream turbine, the flow around the blade tip becomes transonic, and the shock waves are generated in the blade passage. These shock waves induce the boundary layer separation and the vibration of blades, which degrade the efficiency. This unstable flow phenomenon is closely related to the secondary flow associated with the large change in flow direction in the blade passage. To measure the secondary flow, the nonintrusive diagnostic technique is desirable, and the laser-induced fluorescence (LIF) method offers one of the best tools for this purpose. In the present research, the curved nozzle with rectangular cross-section was made to simulate the transonic turbine cascade, and the gas temperature distribution inside the nozzle was obtained by using the LIF method.
