Effect of inlet wake on total pressure loss of a linear turbine rotor cascade

Experiments are carried out to investigate the effect of inlet wake on the total pressure loss of a linear turbine rotor cascade. The test cascade consists of seven blades of 250 mm chord and 100° camber angle. The inlet wake upstream of the cascade is generated by means of a 10 mm thick, 200 mm chord flat plate. The relative circumferential distance (YR/S) between the wake generator (WG) and the leading edge of the cascade blade is varied in discrete steps, while the axial distance between them is kept fixed at 25% of the cascade chord. Velocity measurements at the mid span section are taken upstream to the cascade leading edge at an axial distance of 15% of chord and downstream of the cascade trailing edge at an axial distance of 10% of chord with precalibrated three-hole and five-hole probes respectively. Static pressure measurements are also taken on the blade surfaces. The results of the experiments indicate that the effect of WG is to increase the total pressure loss coefficient at all the positions tested. The lift coefficient exhibited a maximum when the WG is positioned at YR/S = -0.06.